title: LHC searches for physics beyond the Standard Model with top quarks

abstract:
  Searches are presented for physics beyond the Standard Model involving
top-quark and related signatures. The results are based on proton-proton
collision data corresponding to integrated luminosities between 1 fb-1 and 5
fb-1 collected at a center-of-mass energy of 7 TeV with the ATLAS and CMS
detectors at the Large Hadron Collider in 2011. The data are found to be
consistent with the Standard Model. The non-observation of a signal is
converted to limits at the 95% confidence level on the production cross section
times branching ratio and on the masses of the hypothesized new particles for
appropriate benchmark models.


title: Interference Networks with No CSIT: Impact of Topology

abstract:
  We consider partially-connected $K$-user interference networks, where the
transmitters have no knowledge about the channel gain values, but they are
aware of network topology (or connectivity). We introduce several linear
algebraic and graph theoretic concepts to derive new topology-based outer
bounds and inner bounds on the symmetric degrees-of-freedom (DoF) of these
networks. We evaluate our bounds for two classes of networks to demonstrate
their tightness for most networks in these classes, quantify the gain of our
inner bounds over benchmark interference management strategies, and illustrate
the effect of network topology on these gains.


title: Feshbach resonances in a nonseparable trap

abstract:
  We consider a pair of atoms in an arbitrary trapping potential in the
presence of magnetically tunable Feshbach resonance. We find the energy levels
and occupation of the bound molecular states taking into account possible
coupling between center of mass and relative motion induced by the trap. As a
specific example we discuss the case of different atomic species in harmonic
potential, where each atom feels different trapping frequency.


title:
On the three dimensional minimal model program in positive
  characteristic

abstract:
  Let $f:(X,B)\to Z$ be a 3-fold extremal dlt flipping contraction defined over
an algebraically closed field of characteristic $p>5$, such that the
coefficients of $\{B\}$ are in the standard set $\{1-\frac 1n|n\in \mathbb
N\}$, then the flip of $f$ exists. As a consequence, we prove the existence of
minimal models for any projective $\Q$-factorial terminal variety $X$ with
pseudo-effective canonical divisor $K_X$.


title: Siegel Modular Varieties and the Eisenstein Cohomology of $\PGL_{2g+1}$

abstract:
  We use the twisted topological trace formula developed in an earlier paper to
understand liftings from symplectic to general linear groups. We analyse the
lift from $\SP_{2g}$ to $\PGL_{2g+1}$ over the ground field $\Q$ in further
detail, and we get a description of the image of this lift for the $L^2$
cohomology of $\SP_{2g}$ (which is related to the intersection cohomology of
the Shimura variety attached to $\GSp_{2g}$) in terms of the Eisenstein
cohomology of the general linear group, whose building constituents are
cuspidal representations of Levi groups. This description may be used to
understand endoscopic and CAP-representations of the symplectic group.


title:
Challenging claims of "elliptic flow" by comparing azimuth quadrupole
  and jet-related angular correlations from Au-Au collisions at $\sqrt{s_{NN}}
  = $ 62 and 200 GeV

abstract:
  Background: A component of azimuth correlations from high-energy heavy ion
collisions varying as $\cos(2\phi)$ and denoted by symbol $v_2$ is
conventionally interpreted to represent "elliptic flow," a hydrodynamic
manifestation of the initial-state \aa overlap geometry. Several numerical
methods are used to estimate $v_2$, resulting in various combinations of "flow"
and "nonflow" that reveal systematic biases in the $v_2$ estimates. QCD jets
contribute strongly to azimuth correlations and specifically to the
$\cos(2\phi)$ component. Purpose: We question the extent of jet-related
("nonflow") bias in and hydrodynamic "flow" interpretations of $v_2$
measurements. Method: We introduce two-dimensional (2D) model fits to angular
correlation data that distinguish accurately between jet-related correlation
components and a {\em nonjet azimuth quadrupole} that might represent "elliptic
flow" if that were relevant. We compare measured jet-related and "flow"-related
data systematics and determine the jet-related contribution to $v_2$
measurements. Results: Jet structure does introduce substantial bias to
conventional $v_2$ measurements, making interpretation difficult. The nonjet
quadrupole exhibits very simple systematics on centrality and collision
energy---the two variables factorize. Within a \auau centrality interval where
jets show no indication of rescattering or medium effects the nonjet quadrupole
amplitude rises to 60% of its maximum value. Conclusions: Disagreements between
nonjet quadrupole systematics and hydro theory expectations, the large
quadrupole amplitudes observed in more-peripheral \auau collisions and a
significant nonzero value in \nn $\approx$ \pp collisions strongly suggest that
the nonjet quadrupole does not arise from a hydrodynamic "flow" mechanism.


title: Spaces of matrices with few eigenvalues

abstract:
  Let K be a (commutative) field with characteristic not 2, and V be a linear
subspace of n by n matrices that have at most two eigenvalues in K
(respectively, at most one non-zero eigenvalue in K). We prove that the
dimension of V is less than or equal to n(n-1)/2 provided that n be greater
than 2 (respectively, the dimension of V is less than or equal to n(n-1)/2).
  We also classify, up to similarity, the linear subspaces of n by n matrices
in which every matrix has at most two eigenvalues (respectively, at most one
non-zero eigenvalue) in an algebraic closure of K and which have the maximal
dimension among such spaces.


title:
Binary populations in Milky Way satellite galaxies: constraints from
  multi-epoch data in the Carina, Fornax, Sculptor and Sextans dwarf spheroidal
  galaxies

abstract:
  We introduce a likelihood analysis of multi-epoch stellar line-of-sight
velocities to constrain the binary fractions and binary period distributions of
dwarf spheroidal galaxies. This method is applied to multi-epoch data from the
Magellan/MMFS survey of the Carina, Fornax, Sculptor and Sextans dSph galaxies,
after applying a model for the measurement errors that accounts for binary
orbital motion. We find that the Fornax, Sculptor, and Sextans dSphs are
consistent with having binary populations similar to that of Milky Way field
binaries to within 68% confidence limits, whereas the Carina dSph is remarkably
deficient in binaries with periods less than ~10 years. If Carina is assumed to
have a period distribution identical to that of the Milky Way field, its
best-fit binary fraction is 0.14^{+0.28}_{-0.05}, and is constrained to be less
than 0.5 at the 90% confidence level; thus it is unlikely to host a binary
population identical to that of the Milky Way field. By contrast, the best-fit
binary fraction of the combined sample of all four galaxies is
0.46^{+0.13}_{-0.09}, consistent with that of Milky Way field binaries. More
generally, we infer probability distributions in binary fraction, mean orbital
period, and dispersion of periods for each galaxy in the sample. Looking ahead
to future surveys, we show that the allowed parameter space of binary fraction
and period distribution parameters in dSphs will be narrowed significantly by a
large multi-epoch survey. However, there is a degeneracy between the parameters
that is unlikely to be broken unless the measurement error is of order ~0.1
km/s or smaller, presently attainable only by a high-resolution spectrograph.


title: Quantum Markovian Kinetic Equation for Harmonic Oscillator

abstract:
  Specific nonequilibrium states of the quantum harmonic oscillator described
by the Lindblad equation have been hereby suggested. This equation makes it
possible to determine time-varying effects produced by statistical operator or
statistical matrix. Thus, respective representation-varied equilibrium
statistical matrixes have been found. Specific mean value equations have been
found and their equilibrium solutions have been obtained.


title: Graph Layouts via Layered Separators

abstract:
  A k-queue layout of a graph consists of a total order of the vertices, and a
partition of the edges into k sets such that no two edges that are in the same
set are nested with respect to the vertex ordering. A k-track layout of a graph
consists of a vertex k-colouring, and a total order of each vertex colour
class, such that between each pair of colour classes no two edges cross. The
queue-number (track-number) of a graph G, is the minimum k such that G has a
k-queue (k-track) layout.
  This paper proves that every n-vertex planar graph has track number and queue
number at most O(log n). This improves the result of Di Battista, Frati and
Pach [Foundations of Computer Science, (FOCS '10), pp. 365--374] who proved the
first sub-polynomial bounds on the queue number and track number of planar
graphs. Specifically, they obtained O(log^2 n) queue number and O(log^8 n)
track number bounds for planar graphs.
  The result also implies that every planar graph has a 3D crossing-free grid
drawing in O(n log n) volume. The proof uses a non-standard type of graph
separators.


title: The $K$-theory of the Compact Quantum Group $SU_q(2)$ for $q=-1$

abstract:
  We determine the $K$-theory of the $C^{*}$-algebra $C(SU_{-1}(2))$ and
describe its spectrum. Moreover, we exhibit a continuous $C^{*}$-bundle over
$[-1,0)$ whose fibre at $q$ is isomorphic to $C(SU_{q}(2))$.


title:
Simplex Z_2 spin liquids on the Kagome lattice with Entangled Pair
  States: spinon and vison coherence lengths, topological entropy and gapless
  edge modes

abstract:
  Gapped Z_2 spin liquids have been proposed as candidates for the ground-state
of the S=1/2 quantum antiferromagnet on the Kagome lattice. We extend the use
of Projected Entangled Pair States to construct (on the cylinder)Resonating
Valence Bond (RVB) states including both nearest-neighbor and next-nearest
neighbor singlet bonds. Our ansatz -- dubbed "simplex spin liquid" -- allows
for an asymmetry between the two types of triangles (of order 2-3% in the
energy density after optimization) leading to the breaking of inversion
symmetry. We show that the topological Z_2 structure is still preserved and, by
considering the presence or the absence of spinon and vison lines along an
infinite cylinder, we explicitly construct four orthogonal RVB Minimally
Entangled States. The spinon and vison coherence lengths are extracted from a
finite size scaling w.r.t the cylinder perimeter of the energy splittings of
the four sectors and are found to be of the order of the lattice spacing. The
entanglement spectrum of a partitioned (infinite) cylinder is found to be
gapless suggesting the occurrence, on a cylinder with {\it real} open
boundaries, of gapless edge modes formally similar to Luttinger liquid
(non-chiral) spin and charge modes. When inversion symmetry is spontaneously
broken, the RVB spin liquid exhibits an extra Ising degeneracy, which might
have been observed in recent exact diagonalisation studies.


title:
The effect of an infrared divergent quark-antiquark interaction kernel
  on other Green functions

abstract:
  The n-point Green functions of Landau gauge QCD are systematically
investigated in a Dyson-Schwinger approach assuming a static linearly rising
potential between fundamental color charges. Besides quarks also scalar matter
in the fundamental representation is considered. Starting from the hypothesis
of an 1/k^4 infrared divergent matter-antimatter vertex restrictions on the
general color tensor structure of this divergence are derived. Consequences for
the other four-point functions of QCD, resp., scalar QCD, are presented. Hereby
Casimir scaling is found. It is shown that possible singular contributions to
the three-point functions vanish due to cancellations within the color algebra.
On the other hand, higher n-point functions inherit the infrared singularity of
the matter-antimatter vertex in certain color channels. The presented results
show that linear confinement is consistently possible in a Greens function
approach, however, at the expense that the decoupling theorem is circumvented
by infrared singularities.


title:
Discerning electronic fingerprints of nodal and antinodal nestings and
  their phase coherences in doped cuprate superconductors

abstract:
  The complexity of competing orders in cuprates has recently been multiplied
by a number of bulk evidences of charge ordering with wavevector that connects
the antinodal region of the Fermi surface. This results contradicts many
spectroscopic results of the nodal nesting. To resolve this issue, we carry out
a unified study of the resulting electronic fingerprints of both nodal and
antinodal nestings (NNs/ANs), and compare with angle-resolved photoemission,
scanning tunneling spectroscopic data, as well as bulk sensitive Hall effect
measurements. Our result makes several definitive distinctions between them in
that while both nestings gap out the antinodal region, AN induces an additional
quasiparticle gap {\em below the Fermi level along the nodal direction}, which
is so far uncharted in spectroscopic data. Furthermore, we show that the Hall
coefficient in the AN state obtains a discontinuous jump at the phase
transition from an electron-like nodal pocket (negative value) to a large
hole-like Fermi surface (positive value), in contrast to a continuous
transition in the available data. Finally, we write down a Ginzburg-Landau
functional to study the stability of the two phases, and discuss an interesting
possibility of disorder pinned `chiral' charge ordering.


title:
Highly Available Transactions: Virtues and Limitations (Extended
  Version)

abstract:
  To minimize network latency and remain online during server failures and
network partitions, many modern distributed data storage systems eschew
transactional functionality, which provides strong semantic guarantees for
groups of multiple operations over multiple data items. In this work, we
consider the problem of providing Highly Available Transactions (HATs):
transactional guarantees that do not suffer unavailability during system
partitions or incur high network latency. We introduce a taxonomy of highly
available systems and analyze existing ACID isolation and distributed data
consistency guarantees to identify which can and cannot be achieved in HAT
systems. This unifies the literature on weak transactional isolation, replica
consistency, and highly available systems. We analytically and experimentally
quantify the availability and performance benefits of HATs--often two to three
orders of magnitude over wide-area networks--and discuss their necessary
semantic compromises.


title:
Physical Removal of Metallic Carbon Nanotubes from Nanotube Network
  Devices Using a Thermal and Fluidic Process

abstract:
  Electronic and optoelectronic devices based on thin films of carbon nanotubes
are currently limited by the presence of metallic nanotubes. Here we present a
novel approach based on nanotube alkyl functionalization to physically remove
the metallic nanotubes from such network devices. The process relies on
preferential thermal desorption of the alkyls from the semiconducting nanotubes
and the subsequent dissolution and selective removal of the metallic nanotubes
in chloroform. The approach is versatile and is applied to devices
post-fabrication.


title:
Collective motion and nonequilibrium cluster formation in colonies of
  gliding bacteria

abstract:
  We characterize cell motion in experiments and show that the transition to
collective motion in colonies of gliding bacterial cells confined to a
monolayer appears through the organization of cells into larger moving
clusters. Collective motion by non-equilibrium cluster formation is detected
for a critical cell packing fraction around 17%. This transition is
characterized by a scale-free power-law cluster size distribution, with an
exponent $0.88\pm0.07$, and the appearance of giant number fluctuations. Our
findings are in quantitative agreement with simulations of self-propelled rods.
This suggests that the interplay of self-propulsion of bacteria and the
rod-shape of bacteria is sufficient to induce collective motion.


title: On the Intersection Algebra of Principal Ideals

abstract:
  We study the finite generation of the intersection algebra of two principal
ideals I and J in a unique factorization domain R. We provide an algorithm that
produces a list of generators of this algebra over R. In the special case that
R is a polynomial ring, this algorithm has been implemented in the commutative
algebra software system Macaulay2. A new class of algebras, called fan
algebras, is introduced.


title: Casimir interaction energies for magneto-electric \delta-function plates

abstract:
  We present boundary conditions for the electromagnetic fields on a
\delta-function plate, having both electric and magnetic properties, sandwiched
between two magneto-electric semi-infinite half spaces. The optical properties
for an isolated \delta-function plate are shown to be independent of the
longitudinal material properties of the plate. The Casimir-Polder energy
between an isotropically polarizable atom and a magneto-electric
\delta-function plate is attractive for a purely electric \delta-function
plate, repulsive for a purely magnetic \delta-function plate, and vanishes for
the simultaneous perfect conductor limit of both electric and magnetic
properties of the \delta-function plate. The interaction energy between two
identical \delta-function plates is always attractive. It can be attractive or
repulsive when the plates have electric and magnetic properties interchanged
and reproduces Boyer's result for the interaction energy between perfectly
conducting electric and magnetic plates. The change in the Casimir-Polder
energy in the presence of a \delta-function plate on a magneto-electric
substrate is substantial when the substrate is a weak dielectric.


title: Inspecting the Higgs for New Weakly Interacting Particles

abstract:
  We explore new physics scenarios which are optimally probed through precision
Higgs measurements rather than direct collider searches. Such theories consist
of additional electroweak charged or singlet states which couple directly to or
mix with the Higgs boson; particles of this kind may be weakly constrained by
direct limits due to their meager production rates and soft decay products. We
present a simplified framework which characterizes the effects of these states
on Higgs physics by way of tree level mixing (with neutral scalars) and loop
level modifications (from electrically charged states), all expressed in terms
of three mixing angles and three loop parameters, respectively. The theory
parameters are constrained and in some cases even fixed by ratios of Higgs
production and decay rates. Our setup is simpler than a general effective
operator analysis, in that we discard parameters irrelevant to Higgs
observables while retaining complex correlations among measurements that arise
due to the underlying mixing and radiative effects. We show that certain
correlated observations are forbidden, e.g. a depleted ratio of Higgs
production from gluon fusion versus vector boson fusion together with a
depleted ratio of Higgs decays to bb versus WW. Moreover, we study the strong
correlation between the Higgs decay rate to gamma gamma and WW and how it can
be violated in the presence of additional electrically charged particles. Our
formalism maps straightforwardly onto a variety of new physics models, such as
the NMSSM. We show, for example, that with a Higgsino of mass > 100 GeV and a
singlet-Higgs coupling of lambda=0.7, the photon signal strength can deviate
from the vector signal strength by up to ~ 40-60% while depleting the vector
signal strength by only 5-15% relative to the Standard Model.


title: Sparse Multiple Kernel Learning with Geometric Convergence Rate

abstract:
  In this paper, we study the problem of sparse multiple kernel learning (MKL),
where the goal is to efficiently learn a combination of a fixed small number of
kernels from a large pool that could lead to a kernel classifier with a small
prediction error. We develop an efficient algorithm based on the greedy
coordinate descent algorithm, that is able to achieve a geometric convergence
rate under appropriate conditions. The convergence rate is achieved by
measuring the size of functional gradients by an empirical $\ell_2$ norm that
depends on the empirical data distribution. This is in contrast to previous
algorithms that use a functional norm to measure the size of gradients, which
is independent from the data samples. We also establish a generalization error
bound of the learned sparse kernel classifier using the technique of local
Rademacher complexity.


title:
Structure and dynamics of interfaces between two coexisting liquid
  crystalline phases

abstract:
  The phase-field-crystal model is used to access the structure and
thermodynamics of interfaces between two coexisting liquid crystalline phases
in two spatial dimensions. Depending on the model parameters there is a variety
of possible coexistences between two liquid crystalline phases including a
plastic triangular crystal (PTC). Here, we calculate numerically the profiles
for the mean density and the nematic order tensor across the interface for
isotropic-PTC and columnar-PTC respectively smectic A-PTC coexistence. As a
general finding, the width of the interface with respect to the nematic order
parameter characterizing the orientational order is larger than the width of
the mean density interface. In approaching the interface from the PTC side, at
first the mean density goes down and then the nematic order parameter follows.
The relative shift of the two profiles can be larger than a full lattice
constant of the plastic crystal. Finally, we also present numerical results for
the dynamic relaxation of an initial order-parameter profile towards its
equilibrium interfacial profile. Our predictions for the interfacial profiles
can in principle be verified in real-space experiments of colloidal
dispersions.


title:
Distributed simulation of city inundation by coupled surface and
  subsurface porous flow for urban flood decision support system

abstract:
  We present a decision support system for flood early warning and disaster
management. It includes the models for data-driven meteorological predictions,
for simulation of atmospheric pressure, wind, long sea waves and seiches; a
module for optimization of flood barrier gates operation; models for stability
assessment of levees and embankments, for simulation of city inundation
dynamics and citizens evacuation scenarios. The novelty of this paper is a
coupled distributed simulation of surface and subsurface flows that can predict
inundation of low-lying inland zones far from the submerged waterfront areas,
as observed in St. Petersburg city during the floods. All the models are
wrapped as software services in the CLAVIRE platform for urgent computing,
which provides workflow management and resource orchestration.


title: Critical Sets for Sudoku and General Graphs

abstract:
  We discuss the problem of finding critical sets in graphs, a concept which
has appeared in a number of guises in the combinatorics and graph theory
literature. The case of the Sudoku graph receives particular attention, because
critical sets correspond to minimal fair puzzles. We define four parameters
associated with the sizes of extremal critical sets and (a) prove several
general results about these parameters' properties, including their
computational intractability, (b) compute their values exactly for some classes
of graphs, (c) obtain bounds for generalized Sudoku graphs, and (d) offer a
number of open questions regarding critical sets and the aforementioned
parameters.


title:
Dual Equivalence Graphs Revisited and the Explicit Schur Expansion of a
  Family of LLT Polynomials

abstract:
  In 2007 Sami Assaf introduced dual equivalence graphs as a method for
demonstrating that a quasisymmetric function is Schur positive. The method
involves the creation of a graph whose vertices are weighted by Ira Gessel's
fundamental quasisymmetric functions so that the sum of the weights of a
connected component is a single Schur function. In this paper, we improve on
Assaf's axiomatization of such graphs, giving locally testable criteria that
are more easily verified by computers. We further advance the theory of dual
equivalence graphs by describing a broader class of graphs that correspond to
an explicit Schur expansion in terms of Yamanouchi words. Along the way, we
demonstrate several symmetries in the structure of dual equivalence graphs. We
then apply these techniques to give explicit Schur expansions for a family of
Lascoux-Leclerc-Thibon polynomials. This family properly contains the
previously known case of polynomials indexed by two skew shapes, as was
described in a 1995 paper by Christophe Carr\'e and Bernard Leclerc. As an
immediate corollary, we gain an explicit Schur expansion for a family of
modified Macdonald polynomials in terms of Yamanouchi words. This family
includes all polynomials indexed by shapes with at most three cells in the
first row and at most two cells in the second row, providing an extension to
the combinatorial description of the two column case described in 2005 by James
Haglund, Mark Haiman, and Nick Loehr.


title: Dynamic Spectrum Refarming with Overlay for Legacy Devices

abstract:
  The explosive growth in data traffic is resulting in a spectrum crunch
forcing many wireless network operators to look towards refarming their 2G
spectrum and deploy more spectrally efficient Long Term Evolution (LTE)
technology. However, mobile network operators face a challenge when it comes to
spectrum refarming because 2G technologies such as Global System for Mobile
(GSM) is still widely used for low bandwidth machine-to-machine (M2M) devices.
M2M devices typically have long life cycles, e.g. smart meters, and it is
expensive to migrate these devices to newer technology since a truck roll will
typically be required to the site where a device is deployed. Furthermore, with
cost of 2G modules several times less than that of LTE, even newly deployed M2M
devices tend to adopt 2G technology. Nevertheless, operators are keen to either
force their 2G M2M customers to migrate so that they can refarm the spectrum or
set aside a portion of the 2G spectrum for continuing operating 2G and only
refarm the rest for LTE. In this paper we propose a novel solution to provide
GSM connectivity within an LTE carrier through an efficient overlay by
reserving a few physical resource blocks for GSM. With this approach, operators
can refarm their 2G spectrum to LTE efficiently while still providing some GSM
connectivity to their low data rate M2M customers. Furthermore, spectrum can be
dynamically shared between LTE and GSM. An approach similar to that proposed in
this paper can also be applied for other narrow band technology overlays over
LTE.


title:
Signal reconstruction in linear mixing systems with different error
  metrics

abstract:
  We consider the problem of reconstructing a signal from noisy measurements in
linear mixing systems. The reconstruction performance is usually quantified by
standard error metrics such as squared error, whereas we consider any additive
error metric. Under the assumption that relaxed belief propagation (BP) can
compute the posterior in the large system limit, we propose a simple, fast, and
highly general algorithm that reconstructs the signal by minimizing the
user-defined error metric. For two example metrics, we provide performance
analysis and convincing numerical results. Finally, our algorithm can be
adjusted to minimize the $\ell_\infty$ error, which is not additive.
Interestingly, $\ell_{\infty}$ minimization only requires to apply a Wiener
filter to the output of relaxed BP.


title:
Transverse Polarization of $\Sigma^{+}(1189)$ in Photoproduction on a
  Hydrogen Target in CLAS

abstract:
  Experimental results on the $\Sigma^+(1189)$ hyperon transverse polarization
in photoproduction on a hydrogen target using the CLAS detector at Jefferson
laboratory are presented. The $\Sigma^+(1189)$ was reconstructed in the
exclusive reaction $\gamma+p\rightarrow K^{0}_{S} + \Sigma^+(1189)$ via the
$\Sigma^{+} \to p \pi^{0}$ decay mode. The $K^{0}_S$ was reconstructed in the
invariant mass of two oppositely charged pions with the $\pi^0$ identified in
the missing mass of the detected $p\pi^+\pi^-$ final state. Experimental data
were collected in the photon energy range $E_{\gamma}$ = 1.0-3.5 GeV
($\sqrt{s}$ range 1.66-2.73 GeV). We observe a large negative polarization of
up to 95%. As the mechanism of transverse polarization of hyperons produced in
unpolarized photoproduction experiments is still not well understood, these
results will help to distinguish between different theoretical models on
hyperon production and provide valuable information for the searches of missing
baryon resonances.


title:
Why glass elasticity affects the thermodynamics and fragility of
  super-cooled liquids

abstract:
  Super-cooled liquids are characterized by their fragility: the slowing down
of the dynamics under cooling is more sudden and the jump of specific heat at
the glass transition is generally larger in fragile liquids than in strong
ones. Despite the importance of this quantity in classifying liquids,
explaining what aspects of the microscopic structure controls fragility remains
a challenge. Surprisingly, experiments indicate that the linear elasticity of
the glass -- a purely local property of the free energy landscape -- is a good
predictor of fragility. In particular, materials presenting a large excess of
soft elastic modes, the so-called boson peak, are strong. This is also the case
for network liquids near the rigidity percolation, known to affect elasticity.
Here we introduce a model of the glass transition based on the assumption that
particles can organize locally into distinct configurations, which are coupled
spatially via elasticity. The model captures the mentioned observations
connecting elasticity and fragility. We find that materials presenting an
abundance of soft elastic modes have little elastic frustration: energy is
insensitive to most directions in phase space, leading to a small jump of
specific heat. In this framework strong liquids turn out to lie the closest to
a critical point associated with a rigidity or jamming transition, and their
thermodynamic properties are related to the problem of number partitioning and
to Hopfield nets in the limit of small memory.


title:
A New Constructive Method to Optimize Neural Network Architecture and
  Generalization

abstract:
  In this paper, after analyzing the reasons of poor generalization and
overfitting in neural networks, we consider some noise data as a singular value
of a continuous function - jump discontinuity point. The continuous part can be
approximated with the simplest neural networks, which have good generalization
performance and optimal network architecture, by traditional algorithms such as
constructive algorithm for feed-forward neural networks with incremental
training, BP algorithm, ELM algorithm, various constructive algorithm, RBF
approximation and SVM. At the same time, we will construct RBF neural networks
to fit the singular value with every error in, and we prove that a function
with jumping discontinuity points can be approximated by the simplest neural
networks with a decay RBF neural networks in by each error, and a function with
jumping discontinuity point can be constructively approximated by a decay RBF
neural networks in by each error and the constructive part have no
generalization influence to the whole machine learning system which will
optimize neural network architecture and generalization performance, reduce the
overfitting phenomenon by avoid fitting the noisy data.


title:
A Dual-polarized Broadband Planar Antenna and Channelizing Filter Bank
  for Millimeter Wavelengths

abstract:
  We describe the design, fabrication, and testing of a broadband log-periodic
antenna coupled to multiple cryogenic bolometers. This detector architecture,
optimized here for astrophysical observations, simultaneously receives two
linear polarizations with two octaves of bandwidth at millimeter wavelengths.
The broad bandwidth signal received by the antenna is divided into sub-bands
with integrated in-line frequency-selective filters. We demonstrate two such
filter banks: a diplexer with two sub-bands and a log-periodic channelizer with
seven contiguous sub-bands. These detectors have receiver efficiencies of
20-40% and percent level polarization isolation. Superconducting
transition-edge sensor bolometers detect the power in each sub-band and
polarization. We demonstrate circularly symmetric beam patterns, high
polarization isolation, accurately positioned bands, and high optical
efficiency. The pixel design is applicable to astronomical observations of
intensity and polarization at millimeter through sub-millimeter wavelengths. As
compared with an imaging array of pixels measuring only one band, simultaneous
measurements of multiple bands in each pixel has the potential to result in a
higher signal-to-noise measurement while also providing spectral information.
This development facilitates compact systems with high mapping speeds for
observations that require information in multiple frequency bands.


abstract:
  An SIR epidemic model with free boundary is investigated. This model
describes the transmission of diseases. The behavior of positive solutions to a
reaction-diffusion system in a radially symmetric domain is investigated. The
existence and uniqueness of the global solution are given by the contraction
mapping theorem. Sufficient conditions for the disease vanishing or spreading
are given. Our result shows that the disease will not spread to the whole area
if the basic reproduction number $R_{0}<1$ or the initial infected radius $h_0$
is sufficiently small even that $R_{0}>1$. Moreover, we prove that the disease
will spread to the whole area if $R_{0}>1$ and the initial infected radius
$h_0$ is suitably large.


title: All-Sky Interferometry with Spherical Harmonic Transit Telescopes

abstract:
  In this paper we describe the spherical harmonic transit telescope, a novel
formalism for the analysis of transit radio telescopes. This all-sky approach
bypasses the curved sky complications of traditional interferometry and so is
particularly well suited to the analysis of wide-field radio interferometers.
It enables compact and computationally efficient representations of the data
and its statistics that allow new ways of approaching important problems like
map-making and foreground removal. In particular, we show how it enables the
use of the Karhunen-Loeve transform as a highly effective foreground filter,
suppressing realistic foreground residuals for our fiducial example by at least
a factor twenty below the 21cm signal even in highly contaminated regions of
the sky. This is despite the presence of the angle-frequency mode mixing
inherent in real-world instruments with frequency-dependent beams. We show,
using Fisher forecasting, that foreground cleaning has little effect on power
spectrum constraints compared to hypothetical foreground-free measurements.
Beyond providing a natural real-world data analysis framework for 21cm
telescopes now under construction and future experiments, this formalism allows
accurate power spectrum forecasts to be made that include the interplay of
design constraints and realistic experimental systematics with twenty-first
century 21cm science.


title: Bayesian Entropy Estimation for Countable Discrete Distributions

abstract:
  We consider the problem of estimating Shannon's entropy $H$ from discrete
data, in cases where the number of possible symbols is unknown or even
countably infinite. The Pitman-Yor process, a generalization of Dirichlet
process, provides a tractable prior distribution over the space of countably
infinite discrete distributions, and has found major applications in Bayesian
non-parametric statistics and machine learning. Here we show that it also
provides a natural family of priors for Bayesian entropy estimation, due to the
fact that moments of the induced posterior distribution over $H$ can be
computed analytically. We derive formulas for the posterior mean (Bayes' least
squares estimate) and variance under Dirichlet and Pitman-Yor process priors.
Moreover, we show that a fixed Dirichlet or Pitman-Yor process prior implies a
narrow prior distribution over $H$, meaning the prior strongly determines the
entropy estimate in the under-sampled regime. We derive a family of continuous
mixing measures such that the resulting mixture of Pitman-Yor processes
produces an approximately flat prior over $H$. We show that the resulting
Pitman-Yor Mixture (PYM) entropy estimator is consistent for a large class of
distributions. We explore the theoretical properties of the resulting
estimator, and show that it performs well both in simulation and in application
to real data.


title: Rethinking Globular Cluster Formation

abstract:
  This paper is aimed at emphasizing some of the main hints, constraints and
difficulties we currently have in trying to understand how globular clusters
formed, along with their multiple stellar generations, an issue that must be
regarded as intimately connected to the formation process itself. Thus, the
topics that are addressed include i) the required mass of the progenitor, ii)
how to form new stars in an environment already crowded by a previous stellar
generation, iii) how photometry and spectroscopy appear to suggest different
formation processes for second generation stars, iv) whether dilution with
pristine material may (or may not) be necessary for the formation of second
generations, v) why the few clusters with multiple iron abundances are after
all not so different from those that are homogeneous, and finally vi) why
special environmental conditions may not be necessary for the formation of
globular clusters with multiple stellar generations.


title:
The Astrochemical Evolution of Turbulent Giant Molecular Clouds : I -
  Physical Processes and Method of Solution for Hydrodynamic, Embedded Starless
  Clouds

abstract:
  Contemporary galactic star formation occurs predominantly within
gravitationally unstable, cold, dense molecular gas within supersonic,
turbulent, magnetized giant molecular clouds (GMCs). Significantly, because the
chemical evolution timescale and the turbulent eddy-turnover timescale are
comparable at typical GMC conditions, molecules evolve via inherently
non-equilibrium chemistry which is strongly coupled to the dynamical evolution
of the cloud.
  Current numerical simulation techniques, which include at most three decades
in length scale, can just begin to bridge the divide between the global
dynamical time of supersonic turbulent GMCs, and the thermal and chemical
evolution within the thin post-shock cooling layers of their background
turbulence. We address this GMC astrochemical scales problem using a solution
methodology, which permits both complex three-dimensional turbulent dynamics as
well as accurate treatment of non-equilibrium post-shock thermodynamics and
chemistry.
  We present the current methodology in the context of the larger scope of
physical processes important in understanding the chemical evolution of GMCs,
including gas-phase chemistry, dust grains and surface chemistry, and turbulent
heating. We present results of a new Lagrangian verification test for
supersonic turbulence. We characterize the evolution of these species according
to the dimensionless local post-shock Damk\"{o}hler number, which quantifies
the ratio of the dynamical time in the post-shock cooling flow to the chemical
reaction time of a given species.
  Lastly, we discuss implications of this work to the selection of GMC
molecular tracers, and the zeroing of chemical clocks of GMC cores.


title:
A note on Khovanov-Rozansky $sl_2$-homology and ordinary Khovanov
  homology

abstract:
  In this note we present an explicit isomorphism between Khovanov-Rozansky
$sl_2$-homology and ordinary Khovanov homology. This result was originally
stated in Khovanov and Rozansky's paper \cite{KRI}, though the details have yet
to appear in the literature. The main missing detail is providing a coherent
choice of signs when identifying variables in the $sl_2$-homology. Along with
the behavior of the signs and local orientations in the $sl_2$-homology, both
theories behave differently when we try to extend their definitions to virtual
links, which seemed to suggest that the $sl_2$-homology may instead correspond
to a different variant of Khovanov homology. In this paper we describe both
theories and prove that they are in fact isomorphic by showing that a coherent
choice of signs can be made. In doing so we emphasize the interpretation of the
$sl_2$-complex as a cube of resolutions.


title:
Effect of Dimensionality on the Percolation Thresholds of Various
  $d$-Dimensional Lattices

abstract:
  We show analytically that the $[0,1]$, $[1,1]$ and $[2,1]$ Pad{\'e}
approximants of the mean cluster number $S(p)$ for site and bond percolation on
general $d$-dimensional lattices are upper bounds on this quantity in any
Euclidean dimension $d$, where $p$ is the occupation probability. These results
lead to certain lower bounds on the percolation threshold $p_c$ that become
progressively tighter as $d$ increases and asymptotically exact as $d$ becomes
large. These lower-bound estimates depend on the structure of the
$d$-dimensional lattice and whether site or bond percolation is being
considered. We obtain explicit bounds on $p_c$ for both site and bond
percolation on five different lattices: $d$-dimensional generalizations of the
simple-cubic, body-centered-cubic and face-centered-cubic Bravais lattices as
well as the $d$-dimensional generalizations of the diamond and kagom{\'e} (or
pyrochlore) non-Bravais lattices. These analytical estimates are used to assess
available simulation results across dimensions (up through $d=13$ in some
cases). It is noteworthy that the tightest lower bound provides reasonable
estimates of $p_c$ in relatively low dimensions and becomes increasingly
accurate as $d$ grows. We also derive high-dimensional asymptotic expansions
for $p_c$ for the ten percolation problems and compare them to the
Bethe-lattice approximation. Finally, we remark on the radius of convergence of
the series expansion of $S$ in powers of $p$ as the dimension grows.


title: Effective Results on the Waring Problem for Finite Simple Groups

abstract:
  Let G be a finite quasisimple group of Lie type. We show that there are
regular semisimple elements x,y in G, x of prime order, and |y| is divisible by
at most two primes, such that the product of the conjugacy classes of x and y
contain all non-central elements of G. In fact in all but four cases, y can be
chosen to be of square-free order. Using this result, we prove an effective
version of one of the main results of Larsen, Shalev and Tiep by showing that,
given any positive integer m, if the order of a finite simple group S is at
least f(m) for a specified function f, then every element in S is a product of
two mth powers. Furthermore, the verbal width of the mth power word on any
finite simple group S is at most g(m) for a specified function g. We also show
that, given any two non-trivial words v, w, if G is a finite quasisimple group
of large enough order, then v(G)w(G) contains all non-central elements of G.


title: Class Algebra for Ontology Reasoning

abstract:
  Class algebra provides a natural framework for sharing of ISA hierarchies
between users that may be unaware of each other's definitions. This permits
data from relational databases, object-oriented databases, and tagged XML
documents to be unioned into one distributed ontology, sharable by all users
without the need for prior negotiation or the development of a "standard"
ontology for each field. Moreover, class algebra produces a functional
correspondence between a class's class algebraic definition (i.e. its "intent")
and the set of all instances which satisfy the expression (i.e. its "extent").
The framework thus provides assistance in quickly locating examples and
counterexamples of various definitions. This kind of information is very
valuable when developing models of the real world, and serves as an invaluable
tool assisting in the proof of theorems concerning these class algebra
expressions. Finally, the relative frequencies of objects in the ISA hierarchy
can produce a useful Boolean algebra of probabilities. The probabilities can be
used by traditional information-theoretic classification methodologies to
obtain optimal ways of classifying objects in the database.


title:
Very Rapid High-Amplitude Gamma-ray Variability in Luminous Blazar PKS
  1510-089 Studied with Fermi-LAT

abstract:
  Here we report on the detailed analysis of the gamma-ray light curve of a
luminous blazar PKS1510-089 observed in the GeV range with the Large Area
Telescope (LAT) onboard the Fermi satellite during the period 2011 September --
December. By investigating the properties of the detected three major flares
with the shortest possible time binning allowed by the photon statistics, we
find a variety of temporal characteristics and variability patterns. This
includes a clearly asymmetric profile (with a faster flux rise and a slower
decay) of the flare resolved on sub-daily timescales, a superposition of many
short uncorrelated flaring events forming the apparently coherent
longer-duration outburst, and a huge single isolated outburst unresolved down
to the timescale of three-hours. In the latter case we estimate the
corresponding gamma-ray flux doubling timescale to be below one hour, which is
extreme and never previously reported for any active galaxy in the GeV range.
The other unique finding is that the total power released during the studied
rapid and high-amplitude flares constitute the bulk of the power radiatively
dissipated in the source, and a significant fraction of the total kinetic
luminosity of the underlying relativistic outflow. Our analysis allows us to
access directly the characteristic timescales involved in shaping the energy
dissipation processes in the source, and to provide constraints on the location
and the structure of the blazar emission zone in PKS1510-089.


title: Sharp Inequalities for $f$-divergences

abstract:
  $f$-divergences are a general class of divergences between probability
measures which include as special cases many commonly used divergences in
probability, mathematical statistics and information theory such as
Kullback-Leibler divergence, chi-squared divergence, squared Hellinger
distance, total variation distance etc. In this paper, we study the problem of
maximizing or minimizing an $f$-divergence between two probability measures
subject to a finite number of constraints on other $f$-divergences. We show
that these infinite-dimensional optimization problems can all be reduced to
optimization problems over small finite dimensional spaces which are tractable.
Our results lead to a comprehensive and unified treatment of the problem of
obtaining sharp inequalities between $f$-divergences. We demonstrate that many
of the existing results on inequalities between $f$-divergences can be obtained
as special cases of our results and we also improve on some existing non-sharp
inequalities.

categories: math.ST cs.IT math.IT math.OC math.PR stat.ML stat.TH


title: Perancangan basisdata sistem informasi penggajian

abstract:
  The purpose of this research is to design database scheme of information
system at XYZ University. By using database design methods (conceptual scheme,
logical scheme, & physical scheme) the writer designs payroll information
system. The physical scheme is compatible with Borland Delphi Database Engine
Scheme to support the implementation of the I.S. After 3 (three) steps we get 7
(seven) tables, dan 6 (six) forms. By using this shemce, the system can produce
several reports quickly, accurately, efficiently, and effectively.


title:
Analisis laporan tugas akhir mahasiswa Diploma I dari sudut pandang
  kaidah ilmiah dan penggunaan teknologi informasi

abstract:
  The purposes of this research are: 1) to analyze final report from scientific
role, 2) the use of information technology (IT), and 3) to conduct academic
athmosphere in research area. This research gives contributions to study
program of MI-DI, such as: 1) to know the pattern of student final report from
scientific role and the use of IT, 2) give input to study program for next
final report scheme, and 3) can be used for next research reference. If we look
to the quality of final report, there are several focuses to be prepared on
tittle, literature review, methodology, results of report, discussion and also
conclusion. But for the use of IT is already good but the varian is decrease.


title:
Achieving the Quantum Ground State of a Mechanical Oscillator using a
  Bose-Einstein Condensate with Back-Action and Cold Damping feedback schemes

abstract:
  We present a detailed study to show the possibility of approaching the
quantum ground-state of a hybrid optomechanical quantum device formed by a
Bose-Einstein condensate (BEC) confined inside a high-finesse optical cavity
with an oscillatory end mirror. Cooling is achieved using two experimentally
realizable schemes: back-action cooling and cold damping quantum feedback
cooling. In both the schemes, we found that increasing the two body atom-atom
interaction brings the mechanical oscillator to its quantum ground state. It
has been observed that back-action cooling is more effective in the good cavity
limit while the cold damping cooling scheme is more relevant in the bad cavity
limit. It is also shown that in the cold damping scheme, the device is more
efficient in the presence of BEC than in the absence of BEC.


title:
Superconducting Properties and Phase Diagram of Indirectly
  Electron-Doped (Sr1-xLax)Fe2As2 Epitaxial Films Grown by Pulsed Laser
  Deposition

abstract:
  A non-equilibrium phase (Sr1-xLax)Fe2As2 was formed by epitaxial film-growth.
The resulting films emerged superconductivity along with suppression of the
resistivity anomaly that is associated with magnetic and structural phase
transitions. The maximum critical temperature was 20.8 K, which is almost the
same as that of directly electron-doped Sr(Fe1-xCox)2As2. Its electronic phase
diagram is much similar to that of Sr(Fe1-xCox)2As2, indicating that the
difference in the electron doping sites does not influence the superconducting
properties of 122-type SrFe2As2.


title: Cross-over between different symmetries

abstract:
  The yrast states of even even vibrational and transitional nuclei are
interpreted as a rotating condensate of interacting d-bosons. The corresponding
semi-classical tidal wave concept is used for microscopic calculations of
energies and E2 transition probabilities. The strong octupole correlations in
the light rare earth and actinide nuclides are interpreted as rotation-induced
condensation of interacting f-bosons.


title: Tying knots in light fields

abstract:
  We construct a new family of null solutions to Maxwell's equations in free
space whose field lines encode all torus knots and links. The evolution of
these null fields, analogous to a compressible flow along the Poynting vector
that is both geodesic and shear-free, preserves the topology of the knots and
links. Our approach combines the Bateman and spinor formalisms for the
construction of null fields with complex polynomials on $\mathbb{S}^3$. We
examine and illustrate the geometry and evolution of the solutions, making
manifest the structure of nested knotted tori filled by the field lines.

categories: math-ph hep-th math.GN math.MP physics.class-ph physics.optics


title:
Effects of pressure on the ferromagnetic state of the CDW compound
  SmNiC2

abstract:
  We report the pressure response of charge-density-wave (CDW) and
ferromagnetic (FM) phases of the rare-earth intermetallic SmNiC2 up to 5.5 GPa.
The CDW transition temperature (T_{CDW}), which is reflected as a sharp
inflection in the electrical resistivity, is almost independent of pressure up
to 2.18 GPa but is strongly enhanced at higher pressures, increasing from 155.7
K at 2.2 GPa to 279.3 K at 5.5 GPa. Commensurate with the sharp increase in
T_{CDW}, the first-order FM phase transition, which decreases with applied
pressure, bifurcates into the upper (T_{M1}) and lower (T_c) phase transitions
and the lower transition changes its nature to second order above 2.18 GPa.
Enhancement both in the residual resistivity and the Fermi-liquid T^2
coefficient A near 3.8 GPa suggests abundant magnetic quantum fluctuations that
arise from the possible presence of a FM quantum critical point.


title: Prospects for asteroseismology of rapidly rotating B-type stars

abstract:
  In rapidly rotating stars Coriolis forces and centrifugal deformations modify
the properties of oscillations; the Coriolis force is important for
low-frequency modes, while the centrifugal deformation affects mainly p-modes.
Here, we discuss properties of g- and r-mode oscillations in rotating stars.
Predicted frequency spectra of high-order g-modes (and r-modes) excited in
rapidly rotating stars show frequency groupings associated with azimuthal order
$m$. We compare such properties with observations in rapidly rotating Be stars,
and discuss what is learnt from such comparisons.


title:
On the single-electron theory of quantum spin Hall effect in two
  dimensional topological insulators

abstract:
  Recently we wrote a paper on the theory of the quantum spin Hall effect(QSHE)
in two dimensional(2D) topological insulators(TIs)1 which have been considered
as do not add much new insight to the exhaustively studied topic of TI within a
single-electron picture by the referees. In this paper we review the papers on
the mechanism of the QSHE which have significant influence on understanding of
the subject. By illustrating the failures of the previous works we show our
paper do contribute a different point of view to this topic, which we believe
is not only a new but also the correct way to approach the problem at the
single-electron level.


title: Nonassociatuve generalization of supersymmetry

abstract:
  A nonassociative generalization of supersymmetry is studied, where
supersymmetry generators are considered to be the nonassociative ones.
Associators for the product of three and four multipliers are defined. Using a
special choice of the parameters, it is shown that the associator of the
product of four supersymmetry generators is connected with the angular momentum
operator. The connection of operator decomposition to the hidden variables
theory and alternative quantum mechanics is discussed.


title:
An Efficient CCA2-Secure Variant of the McEliece Cryptosystem in the
  Standard Model

abstract:
  Recently, a few chosen-ciphertext secure (CCA2-secure) variants of the
McEliece public-key encryption (PKE) scheme in the standard model were
introduced. All the proposed schemes are based on encryption repetition
paradigm and use general transformation from CPA-secure scheme to a CCA2-secure
one. Therefore, the resulting encryption scheme needs \textit{separate}
encryption and has \textit{large} key size compared to the original scheme,
which complex public key size problem in the code-based PKE schemes. Thus, the
proposed schemes are not sufficiently efficient to be used in practice.
  In this work, we propose an efficient CCA2-secure variant of the McEliece PKE
scheme in the standard model. The main novelty is that, unlike previous
approaches, our approach is a generic conversion and can be applied to
\textit{any} one-way trapdoor function (OW-TDF), the lowest-level security
notion in the context of public-key cryptography, resolving a big fundamental
and central problem that has remained unsolved in the past two decades.


title: Character sums over unions of intervals

abstract:
  We obtain a Burgess-type bound for character sums over unions of intervals.
The result follows from the argument of Heath-Brown, with an improvement in one
of the steps.


title: Quantitative K-Theory Related to Spin Chern Numbers

abstract:
  We examine the various indices defined on pairs of almost commuting unitary
matrices that can detect pairs that are far from commuting pairs. We do this in
two symmetry classes, that of general unitary matrices and that of self-dual
matrices, with an emphasis on quantitative results. We determine which values
of the norm of the commutator guarantee that the indices are defined, where
they are equal, and what quantitative results on the distance to a pair with a
different index are possible. We validate a method of computing spin Chern
numbers that was developed with Hastings and only conjectured to be correct.
Specifically, the Pfaffian-Bott index can be computed by the "log method" for
commutator norms up to a specific constant.


title:
Classification of Lie point symmetries for quadratic
  Li$\acute{\textbf{e}}$nard type equation $\ddot{x}+f(x)\dot{x}^2+g(x)=0$

abstract:
  In this paper we carry out a complete classification of the Lie point
symmetry groups associated with the quadratic Li$\acute{e}$nard type equation,
$\ddot {x} + f(x){\dot {x}}^{2} + g(x)= 0$, where $f(x)$ and $g(x)$ are
arbitrary functions of $x$. The symmetry analysis gets divided into two cases,
$(i)$ the maximal (eight parameter) symmetry group and $(ii)$ non-maximal
(three, two and one parameter) symmetry groups. We identify the most general
form of the quadratic Li$\acute{e}$nard equation in each of these cases. In the
case of eight parameter symmetry group, the identified general equation becomes
linearizable as well as isochronic. We present specific examples of physical
interest. For the nonmaximal cases, the identified equations are all integrable
and include several physically interesting examples such as the
Mathews-Lakshmanan oscillator, particle on a rotating parabolic well, etc. We
also analyse the underlying equivalence transformations.


title: New Dimension Value Introduction for In-Memory What-If Analysis

abstract:
  OLAP systems operate on historical data and provide answers to analysts
queries. Recent in-memory implementations provide significant performance
improvement for real time ad-hoc analysis. Philosophy and techniques of what-if
analysis on data warehouse and in-memory data store based OLAP systems have
been covered in great detail before but exploration of new dimension value
(attribute) introduction has been limited in the context of what-if analysis.
We extend the approach of Andrey Balmin et al of using select modify operator
on data graph to introduce new values for dimensions and measures in a
read-only in-memory data store as scenarios. Our system constructs scenarios
without materializing the rows and stores the row information as queries. The
rows associated with the scenarios are constructed as and when required by an
ad-hoc query.


title: Upper and lower bounds for the function S(t) on the short intervals

abstract:
  We prove under RH the existence of a very large positive and negative values
of the argument of the Riemann zeta function on a very short intervals.


title: Hawking radiation and total entropy change as tunneling

abstract:
  In the frame of Hamilton-Jacobi method, the back-reactions of the radiating
particles together with the total entropy change of the whole system are
investigated. The emission probability from this process is found to be
equivalent to the null geodesic method. However its physical picture is more
clear: the negative energy one of a virtual particle pair is absorbed by the
black hole, resulting in the temperature, electric potential and angular
velocity increase; then the black hole amount of heat, electric charge and
angular momentum can spontaneously transfer to the positive energy particle;
when obtaining enough energy, it can escape away to infinity, visible to
distant observers. And this method can be applied to any sort of horizons and
particles without a specific choice of (regular-across-the-horizon)
coordinates.


title:
An Exact Expression for a Flat Connection on the Complement of a Torus
  Knot

abstract:
  Simple physics ideas are used to derive an exact expression for a flat
connection on the complement of a torus knot. The result is of some
mathematical importance in the context of constructing representations of the
knot group -- a topological invariant of the knot. It is also a step forward in
the direction of obtaining a generalisation of the Aharonov-Bohm effect, in
which charged particles moving through force-free regions are scattered by
impenetrable, knotted solenoids.


title:
Estimation of the population spectral distribution from a large
  dimensional sample covariance matrix

abstract:
  This paper introduces a new method to estimate the spectral distribution of a
population covariance matrix from high-dimensional data. The method is founded
on a meaningful generalization of the seminal Marcenko-Pastur equation,
originally defined in the complex plan, to the real line. Beyond its easy
implementation and the established asymptotic consistency, the new estimator
outperforms two existing estimators from the literature in almost all the
situations tested in a simulation experiment. An application to the analysis of
the correlation matrix of S&P stocks data is also given.


title:
A local moment estimator of the spectrum of a large dimensional
  covariance matrix

abstract:
  This paper considers the problem of estimating the population spectral
distribution from a sample covariance matrix in large dimensional situations.
We generalize the contour-integral based method in Mestre (2008) and present a
local moment estimation procedure. Compared with the original one, the new
procedure can be applied successfully to models where the asymptotic clusters
of sample eigenvalues generated by different population eigenvalues are not all
separate. The proposed estimates are proved to be consistent. Numerical results
illustrate the implementation of the estimation procedure and demonstrate its
efficiency in various cases.


title: A trick around Fibonacci, Lucas and Chebyshev

abstract:
  In this article, we present a trick around Fibonacci numbers which can be
found in several magic books. It consists in computing quickly the sum of the
successive terms of a Fibonacci-like sequence. We give explanations and
extensions of this trick to more general sequences. This study leads us to
interesting connections between Fibonacci, Lucas sequences and Chebyshev
polynomials.


title: The Eclipsing System EP Andromedae and its Circumbinary Companions

abstract:
  We present new long-term CCD photometry for EP And acquired during the period
2007 to 2012. The light curves display total eclipses at primary minima and
season-to-season light variability. Our synthesis for all available light
curves indicates that the eclipsing pair is a W-type overcontact binary with
parameters of q=2.578, i=83.3 deg, $\Delta T$=27 K, f=28 %, and l3=2~3 %. The
asymmetric light curves in 2007 were satisfactorily modeled by a cool spot on
either of the eclipsing components from a magnetic dynamo. Including our 95
timing measurements, a total of 414 times of minimum light spanning about 82 yr
were used for a period study. A detailed analysis of the eclipse timing diagram
revealed that the orbital period of EP And has varied as a combination of an
upward-opening parabola and two periodic variations, with cycle lengths of
P3=44.6 yr and P4=1.834 yr and semi-amplitudes of K3=0.0100 d and K4=0.0039 d,
respectively. The observed period increase at a fractional rate of
+1.39x10^{-10} is in excellent agreement with that calculated from the W-D code
and can be plausibly explained by some combination of mass transfer from the
primary to the secondary star and angular momentum loss due to magnetic
braking. The most reasonable explanation for both cycles is a pair of
light-travel-time effects driven by the possible existence of a third and
fourth component with projected masses of M3=0.25 Msun and M4=0.90 Msun. The
more massive companion could be revealed using high-resolution spectroscopic
data extending over the course of a few years and could also be a binary
itself. It is possible that the circumbinary objects may have played an
important role in the formation and evolution of the eclipsing pair, which
would cause it to have a short initial orbital period and thus evolve into an
overcontact configuration by angular momentum loss.


title:
The maximum order of the elements of a finite symplectic group of even
  characteristic

abstract:
  We give an exact formula, as a function of m and q, for the maximum order of
the elements of the finite symplectic group Sp(2m,q), with q even, and of its
automorphism group.


title: On Weighted Low-Rank Approximation

abstract:
  Our main interest is the low-rank approximation of a matrix in R^m.n under a
weighted Frobenius norm. This norm associates a weight to each of the (m x n)
matrix entries. We conjecture that the number of approximations is at most
min(m, n).
  We also investigate how the approximations depend on the weight-values.


title:
Robust no-free lunch with vanishing risk, a continuum of assets and
  proportional transaction costs

abstract:
  We propose a continuous time model for financial markets with proportional
transactions costs and a continuum of risky assets. This is motivated by bond
markets in which the continuum of assets corresponds to the continuum of
possible maturities. Our framework is well adapted to the study of no-arbitrage
properties and related hedging problems. In particular, we extend the
Fundamental Theorem of Asset Pricing of Guasoni, R\'asonyi and L\'epinette
(2012) which concentrates on the one dimensional case. Namely, we prove that
the Robust No Free Lunch with Vanishing Risk assumption is equivalent to the
existence of a Strictly Consistent Price System. Interestingly, the presence of
transaction costs allows a natural definition of trading strategies and avoids
all the technical and un-natural restrictions due to stochastic integration
that appear in bond models without friction. We restrict to the case where
exchange rates are continuous in time and leave the general c\`adl\`ag case for
further studies.


title: Synchronisation of stochastic oscillators in biochemical systems

abstract:
  A formalism is developed which describes the extent to which stochastic
oscillations in biochemical models are synchronised. It is based on the
calculation of the complex coherence function within the linear noise
approximation. The method is illustrated on a simple example and then applied
to study the synchronisation of chemical concentrations in social amoeba. The
degree to which variation of rate constants in different cells and the volume
of the cells affects synchronisation of the oscillations is explored, and the
phase lag calculated. In all cases the analytical results are shown to be in
good agreement with those obtained through numerical simulations.


title:
Integrability of differential equations with fluid mechanics
  application: from Painleve property to the method of simplest equation

abstract:
  We present a brief overview of integrability of nonlinear ordinary and
partial differential equations with a focus on the Painleve property: an ODE of
second order has the Painleve property if the only movable singularities
connected to this equation are single poles. The importance of this property
can be seen from the Ablowitz-Ramani-Segur conhecture that states that a
nonlinear PDE is solvable by inverse scattering transformation only if each
nonlinear ODE obtained by exact reduction of this PDE has the Painleve
property. The Painleve property motivated motivated much research on obtaining
exact solutions on nonlinear PDEs and leaded in particular to the method of
simplest equation. A version of this method called modified method of simplest
equation is discussed below.


title: Supercritical elliptic problems on a perturbation of the ball

abstract:
  We examine the H\'enon equation $ -\Delta u =|x|^\alpha u^p$ in $ \Omega
\subset \mathbb{R}^N$ with $u=0$ on $ \partial \Omega$ where $ 0 < \alpha$. We
show there exists a sequence $ \{p_k\}_k \subset [ \frac{N+2}{N-2},
p_{\alpha}(N)]$ with $p_1 < p_2 <p_3 < ...$, $ p_k \nearrow p_{\alpha}(N)$ such
that for any $ \frac{N+2}{N-2} \le p < p_{\alpha}(N)$, which avoids $ \{p_k\}_k
$, there exists a positive classical solution of the H\'enon equation, provided
$ \Omega$ is a sufficiently small perturbation of the unit ball. We also
examine the Lane-Emden-Fowler equation in the case of an exterior domain; ie. $
-\Delta u = u^p$ in $ \Omega$, an exterior domain, with $ u=0 $ on $ \partial
\Omega$. We show the existence of $ \frac{N+2}{N-2} \le p_1 < p_2 < p_3<...$
with $ p_k \rightarrow \infty$ such that if $ \frac{N+2}{N-2} < p$, which
avoids $\{p_k\}_k$, then there exists a positive \emph{fast decay} classical
solution, provided $ \Omega$ is a sufficiently small perturbation of the
exterior of the unit ball.


title:
The class of infinite dimensional quasipolaydic equality algebras is not
  finitely axiomatizable over its diagonal free reducts

abstract:
  We show that the class of infinite dimensional quasipolaydic equality
algebras is not finitely axiomatizable over its diagonal free reducts


title: Transfers of entanglement qudit states in quantum networks

abstract:
  The issue of quantum states' transfer -- in particular, for so-called Perfect
State Transfer (PST) -- in the networks represented by the spin chains seems to
be one of the major concerns in quantum computing. Especially, in the context
of future communication methods that can be used in broadly defined computer
science. The chapter presents a definition of Hamiltonian describing the
dynamics of quantum data transfer in one-dimensional spin chain, which is able
to transfer the state of unknown qudits. The main part of the chapter is the
discussion about possibility of entangled states' perfect transfer, in
particular, for the generalized Bell states for qudits. One of the sections
also contains the results of numerical experiments for the transmission of
quantum entangled state in a noisy quantum channel.


title: Order of Decay of Mobile Charge Carriers in P3HT:PCBM Solar Cells

abstract:
  The charge carrier dynamics of organic solar cells are strongly influenced by
trapping and allow to draw conclusions on the loss mechanisms limiting the
photovoltaic performance. In this study we derive the recombination order
\Delta\ of mobile charge carriers. For annealed P3HT:PCBM solar cells, it
allows us to pinpoint the dominant recombination of mobile with trapped charge
carriers in tail states. While the characteristic tail state energy of about 40
meV rises to about 100 meV for 30 h oxygen exposure under illumination, \Delta\
decreases only weakly from 1.70 to 1.62: This corresponds to a slight shift
towards trap-assisted recombination.


title: Cohen-Macaulay-ness in codimension for bipartite graphs

abstract:
  Let $G$ be an unmixed bipartite graph of dimension $d-1$. Assume that
$K_{n,n}$, with $n\ge 2$, is a maximal complete bipartite subgraph of $G$ of
minimum dimension. Then $G$ is Cohen-Macaulay in codimension $d-n+1$. This
generalizes a characterization of Cohen-Macaulay bipartite graphs by Herzog and
Hibi and a result of Cook and Nagel on unmixed Buchsbaum graphs. Furthermore,
we show that any unmixed bipartite graph $G$ which is Cohen-Macaulay in
codimension $t$, is obtained from a Cohen-Macaulay graph by replacing certain
edges of $G$ with complete bipartite graphs. We provide some examples.


title:
Bouncing ball dynamics: simple model of motion of the table and
  sinusoidal motion

abstract:
  Nonlinear dynamics of a bouncing ball moving vertically in a gravitational
field and colliding with a moving limiter is considered and the Poincar\'e map,
describing evolution from an impact to the next impact, is described.
Displacement of the table is approximated in one period by four cubic
polynomials. Results obtained for this model are used to elucidate dynamics of
the standard model of bouncing ball with sinusoidal motion of the limiter.


title:
The role of quantum-well states and carrier scattering times on
  discontinuities in opto-electrical characteristics of SCH lasers

abstract:
  Drift-diffusion computer simulations model available in Synopsys' Sentaurus
TCAD is used to study electrical, I-V, and optical, I-L, characteristics of
separate-confinement heterostructure laser based on $AlGaAs$. We investigate
the role of the width and depth of Quantum Well (QW) active region, below and
above the lasing threshold. The device properties depend on both, the number of
bound QW states and on closeness of the highest bound states to conduction or
valence band offset. The lasing action may not exist at certain widths or
hights of QW, and the threshold current is a discontinuous function of these
parameters. The effects are more pronounced at low temperatures.
Discontinuities in characteristics are found, at certain conditions, in
temperature dependencies as well. The carriers scattering time on QW is shown
to have the crucial role on amplitude of discontinuities.


title:
Carrier density dependence of the magnetic properties in iron-doped
  Bi2Se3 topological insulator

abstract:
  The electronic and magnetic properties of iron-doped topological insulator
Bi1.84-xFe0.16CaxSe3 single crystals were studied. By co-doping Fe and Ca
atoms, ferromagnetic bulk states with different carrier density (from n-type to
p-type) were obtained. Effective magnetic moments for each Fe atom was
estimated as small as about 0.07$\mu$B. Magnetic and non-magnetic phases
separation was observed in all samples. Our results suggest that the bulk
ferromagnetism in Fe-doped Bi2Se3 is not intrinsic and regardless of carrier
density.


title:
Variational calculation of highly excited rovibrational energy levels of
  H2O2

abstract:
  Results are presented for highly accurate ab initio variational calculation
of the rotation - vibration energy levels of H2O2 in its electronic ground
state. These results use a recently computed potential energy surface and the
variational nuclear-motion programmes WARV4, which uses an exact kinetic energy
(EKE) operator, and TROVE, which uses a numerical expansion for the kinetic
energy. The TROVE calculations are performed for levels with high values of
rotational excitation, $J$ up to 35. The purely \ai\ calculations of the
rovibrational energy levels reproduce the observed levels with a standard
deviation of about 1 \cm, similar to that of the $J = 0$ calculation as the
discrepancy between theory and experiment for rotational energies within a
given vibrational state is substantially determined by the error in the
vibrational band origin. Minor adjustments are made to the ab initio
equilibrium geometry and to the height of the torsional barrier. Using these
and correcting the band origins using the error in $J = 0$ states lowers the
standard deviation of the observed $-$ calculated energies to only 0.002 \cm\
for levels up to $J = 10$ and 0.02 \cm\ for all experimentally know energy
levels, which extend up to $J = 35$.


title:
Hamiltonian Brownian motion in Gaussian thermally fluctuating potential.
  I. Exact Langevin equations, invalidity of Marcovian approximation, common
  bottleneck of dynamic noise theories, and diffusivity/mobility 1/f noise

abstract:
  Dynamical random walk of classical particle in thermodynamically equilibrium
fluctuating medium, - Gaussian random potential field, - is considered in the
framework of explicit stochastic representation of deterministic interactions.
We discuss corresponding formally exact Langevin equations for the particle's
trajectory and show that Marcovian kinetic equation approximation to them is
inadequate, - even (and especially) in case of spatially-temporally
short-correlated field, - since ignores such actual effects of exponential
instability of the trajectory (in respect to small perturbations) as scaleless
low-frequency diffusivity/mobility fluctuations (and other excess degrees of
randomness) reflected by third-, fourth- and higher-order long-range
irreducible statistical correlations. We try to catch the latter, - squeezing
through typical theoretical narrow bottleneck, - with the help of an exact
relationship between the instability and diffusivity statistical
characteristics, along with standard analytical d approximations. The result is
quasi-static diffusivity fluctuations which generally are comparable with mean
value of diffusivity and disappear in the limit of infinitely large medium's
correlation length or infinitely small correlation time only, in agreement with
the previously suggested theorem on fundamental 1/f noise.


title: Explicit birational geometry of 3-folds and 4-folds of general type, III

abstract:
  Nonsingular projective 3-folds $V$ of general type can be naturally
classified into 18 families according to the {\it pluricanonical section index}
$\delta(V):=\text{min}\{m|P_m\geq 2\}$ since $1\leq \delta(V)\leq 18$ due to
our previous series (I, II). Based on our further classification to 3-folds
with $\delta(V)\geq 13$ and an intensive geometrical investigation to those
with $\delta(V)\leq 12$, we prove that $\text{Vol}(V) \geq \frac{1}{1680}$ and
that the pluricanonical map $\Phi_{m}$ is birational for all $m \geq 61$, which
greatly improves known results. An optimal birationality of $\Phi_m$ for the
case $\delta(V)=2$ is obtained. As an effective application, we study
projective 4-folds of general type with $p_g\geq 2$ in the last section.


title:
Classical aspects of Hawking radiation verified in analogue gravity
  experiment

abstract:
  There is an analogy between the propagation of fields on a curved spacetime
and shallow water waves in an open channel flow. By placing a streamlined
obstacle into an open channel flow we create a region of high velocity over the
obstacle that can include wave horizons. Long (shallow water) waves propagating
upstream towards this region are blocked and converted into short (deep water)
waves. This is the analogue of the stimulated Hawking emission by a white hole
(the time inverse of a black hole). The measurements of amplitudes of the
converted waves demonstrate that they appear in pairs and are classically
correlated; the spectra of the conversion process is described by a
Boltzmann-distribution; and the Boltzmann-distribution is determined by the
determined by the change in flow across the white hole horizon.


title: Investigation of induced fission of natPb by accelerated 7Li ions

abstract:
  Cross-sections for fragments produced by the fission reaction induced by
accelerated 7Li ions impinged into an natPb target at 245 MeV were obtained. We
have applied the induced-activation method in off-line analysis. The analysis
of charge and mass distributions of fission products allowed the determination
of the total fission cross-section for the 7Li+Pb system. The recoil technique
(thick target- thick catcher), based on the two step model mathematical
formalism, is used to determine the kinematics characteristics of reaction
products. Analysis concerning transferred linear momentum provided information
on the initial projectile-target interaction, and is compared with
proton-induced fission measurements.


title:
Ground states of an Ising model on an extended Shastry-Sutherland
  lattice and the 1/2-magnetization plateau in some rare-earth-metal
  tetraborides

abstract:
  A complete solution of the ground-state problem for an Ising model on the
Shastry-Sutherland lattice with an additional interaction along the diagonals
of "empty" squares in an applied magnetic field is presented. A rigorous proof
is given that this interaction gives rise to a plateau at one-half of the
saturation magnetization. Such a fractional plateau has been observed in some
rare-earth-metal tetraborides, in particular, in strong Ising magnets ErB4
(where it is the only one) and TmB4 (where it is the broadest one), but its
origin has remained unclear. Our study sheds new light on the solution of this
problem.


title:
Analytic and Algorithmic Aspects of Generalized Harmonic Sums and
  Polylogarithms

abstract:
  In recent three--loop calculations of massive Feynman integrals within
Quantum Chromodynamics (QCD) and, e.g., in recent combinatorial problems the
so-called generalized harmonic sums (in short $S$-sums) arise. They are
characterized by rational (or real) numerator weights also different from $\pm
1$. In this article we explore the algorithmic and analytic properties of these
sums systematically. We work out the Mellin and inverse Mellin transform which
connects the sums under consideration with the associated Poincar\'{e} iterated
integrals, also called generalized harmonic polylogarithms. In this regard, we
obtain explicit analytic continuations by means of asymptotic expansions of the
$S$-sums which started to occur frequently in current QCD calculations. In
addition, we derive algebraic and structural relations, like differentiation
w.r.t. the external summation index and different multi-argument relations, for
the compactification of $S$-sum expressions. Finally, we calculate algebraic
relations for infinite $S$-sums, or equivalently for generalized harmonic
polylogarithms evaluated at special values. The corresponding algorithms and
relations are encoded in the computer algebra package {\tt HarmonicSums}.


title: *-Regular Leavitt path algebras of arbitrary graphs

abstract:
  If $K$ is a field with involution and $E$ an arbitrary graph, the involution
from $K$ naturally induces an involution of the Leavitt path algebra $L_K(E).$
We show that the involution on $L_K(E)$ is proper if the involution on $K$ is
positive definite, even in the case when the graph $E$ is not necessarily
finite or row-finite.
  It has been shown that the Leavitt path algebra $L_K(E)$ is regular if and
only if $E$ is acyclic. We give necessary and sufficient conditions for
$L_{K}(E)$ to be $^\ast$-regular (i.e. regular with proper involution). This
characterization of $^\ast$-regularity of a Leavitt path algebra is given in
terms of an algebraic property of $K,$ not just a graph-theoretic property of
$E.$ This differs from the known characterizations of various other algebraic
properties of a Leavitt path algebra in terms of graph-theoretic properties of
$E$ alone.
  As a corollary, we show that Handelman's conjecture (stating that every
$^\ast$-regular ring is unit-regular) holds for Leavitt path algebras.
Moreover, its generalized version for rings with local units also continues to
hold for Leavitt path algebras over arbitrary graphs.


title: Finite choice, convex choice and finding roots

abstract:
  We investigate choice principles in the Weihrauch lattice for finite sets on
the one hand, and convex sets on the other hand. Increasing cardinality and
increasing dimension both correspond to increasing Weihrauch degrees. Moreover,
we demonstrate that the dimension of convex sets can be characterized by the
cardinality of finite sets encodable into them. Precisely, choice from an n+1
point set is reducible to choice from a convex set of dimension n, but not
reducible to choice from a convex set of dimension n-1. Furthermore we consider
searching for zeros of continuous functions. We provide an algorithm producing
3n real numbers containing all zeros of a continuous function with up to n
local minima. This demonstrates that having finitely many zeros is a strictly
weaker condition than having finitely many local extrema. We can prove 3n to be
optimal.


title: Multichannel dynamical symmetry and cluster-coexistence

abstract:
  A composite symmetry of the nuclear structure, called multichannel dynamical
symmetry is established. It can describe different cluster configurations
(defined by different reaction channels) in a unified framework, thus it has a
considerable predictive power. The two-channel case is presented in detail, and
its conceptual similarity to the dynamical supersymmetry is discussed.


title: Indeterminacy of the moment problem for symmetric probability measures

abstract:
  In this paper, the moment problem for symmetric probability measures is
characterized in terms of associated sequences called Jacobi sequences
$\{\omega_n\}$. A notion named property (SC), which is proved to be a necessary
and sufficient condition for the indeterminacy of the moment problem, naturally
arises from the viewpoint of finite dimensional approximation for infinite
matrices. We prove that the moment problem for q-Gaussian not only for $q>1$
but also for $q<-1$ is indeterminate. We also prove that hyperbolic secant
distribution is "the last probability measure" which is uniquely determined by
the moment sequence of power type, just by checking property (SC) with quite
easy calculation.


title: Strongly semihereditary rings and rings with dimension

abstract:
  The existence of a well-behaved dimension of a finite von Neumann algebra
(see [19]) has lead to the study of such a dimension of finite Baer *-rings
(see [26]) that satisfy certain *-ring axioms (used in [9]). This dimension is
closely related to the equivalence relation $\sim^{*}$ on projections defined
by $p\sim^{*} q$ iff $p=xx^*$ and $q=x^*x$ for some $x.$ However, the
equivalence $\sim^{a}$ on projections (or, in general, idempotents) defined by
$p\sim^{a} q$ iff $p=xy$ and $q=yx$ for some $x$ and $y,$ can also be relevant.
There were attempts to unify the two approaches (see [10]).
  In this work, our agenda is three-fold: (1) We study assumptions on a ring
with involution that guarantee the existence of a well-behaved dimension
defined for any general equivalence relation on projections $\sim.$ (2) By
interpreting $\sim$ as $\sim^{a},$ we prove the existence of a well-behaved
dimension of strongly semihereditary rings with a positive definite involution.
This class is wider than the class of finite Baer *-rings with dimension
considered in the past: it includes some non Rickart *-rings. Moreover, none of
the *-ring axioms from [9] and [26] are assumed. (3) As the first corollary of
(2), we obtain dimension of noetherian Leavitt path algebras over positive
definite fields. Secondly, we obtain dimension of a Baer *-ring $R$ satisfying
the first seven axioms from [26] (in particular, dimension of finite
$AW^*$-algebras). Assuming the eight axiom as well, $R$ has dimension for
$\sim^{*}$ also and the two dimensions coincide.


title: Experimental Realization of Nonadiabatic Holonomic Quantum Computation

abstract:
  Due to its geometric nature, holonomic quantum computation is fault-tolerant
against certain types of control errors. Although proposed more than a decade
ago, the experimental realization of holonomic quantum computation is still an
open challenge. In this Letter, we report the first experimental demonstration
of nonadiabatic holonomic quantum computation in liquid NMR quantum information
processors. Two non-commuting holonomic single-qubit gates, rotations about
x-axis and about z-axis, and the two-qubit holonomic control-NOT gate are
realized with high fidelity by evolving the work qubits and an ancillary qubit
nonadiabatically. The successful realization of these universal elementary
gates in nonadiabatic quantum computing demonstrates the experimental
feasibility and the fascinating feature of this fast and resilient quantum
computing paradigm.


title: Global quotients among toric Deligne-Mumford stacks

abstract:
  This work characterizes global quotient stacks---smooth stacks associated to
a finite group acting a manifold---among smooth quotient stacks $[M/G]$, where
$M$ is a smooth manifold equipped with a smooth proper action by a Lie group
$G$. The characterization is described in terms of the action of the connected
component $G_0$ on $M$ and is related to (stacky) fundamental group and
covering theory. This characterization is then applied to smooth toric
Deligne-Mumford stacks, and global quotients among toric DM stacks are then
characterized in terms of their associated combinatorial data of stacky fans.


title: Fast Damage Recovery in Robotics with the T-Resilience Algorithm

abstract:
  Damage recovery is critical for autonomous robots that need to operate for a
long time without assistance. Most current methods are complex and costly
because they require anticipating each potential damage in order to have a
contingency plan ready. As an alternative, we introduce the T-resilience
algorithm, a new algorithm that allows robots to quickly and autonomously
discover compensatory behaviors in unanticipated situations. This algorithm
equips the robot with a self-model and discovers new behaviors by learning to
avoid those that perform differently in the self-model and in reality. Our
algorithm thus does not identify the damaged parts but it implicitly searches
for efficient behaviors that do not use them. We evaluate the T-Resilience
algorithm on a hexapod robot that needs to adapt to leg removal, broken legs
and motor failures; we compare it to stochastic local search, policy gradient
and the self-modeling algorithm proposed by Bongard et al. The behavior of the
robot is assessed on-board thanks to a RGB-D sensor and a SLAM algorithm. Using
only 25 tests on the robot and an overall running time of 20 minutes,
T-Resilience consistently leads to substantially better results than the other
approaches.


title: VOStat: A Statistical Web Service for Astronomers

abstract:
  VOStat is a Web service providing interactive statistical analysis of
astronomical tabular datasets. It is integrated into the suite of analysis and
visualization tools associated with the international Virtual Observatory (VO)
through the SAMP communication system. A user supplies VOStat with a dataset
extracted from the VO, or otherwise acquired, and chooses among $\sim 60$
statistical functions. These include data transformations, plots and summaries,
density estimation, one- and two-sample hypothesis tests, global and local
regressions, multivariate analysis and clustering, spatial analysis,
directional statistics, survival analysis (for censored data like upper
limits), and time series analysis. The statistical operations are performed
using the public domain {\bf R} statistical software environment, including a
small fraction of its $>4000$ {\bf CRAN} add-on packages. The purpose of VOStat
is to facilitate a wider range of statistical analyses than are commonly used
in astronomy, and to promote use of more advanced methodology in {\bf R} and
{\bf CRAN}.


title: A simple observation on random matrices with continuous diagonal entries

abstract:
  Let $T$ be an $n\times n$ random matrix, such that each diagonal entry
$T_{i,i}$ is a continuous random variable, independent from all the other
entries of $T$. Then for every $n\times n$ matrix $A$ and every $t\ge0$ $$
\p\Big[|\det(A+T)|^{1/n}\le t\Big]\le2bnt, $$ where $b>0$ is a uniform upper
bound on the densities of $T_{i,i}$.


title:
Evidence for Diboson Production in the Lepton plus Heavy Flavor Jets
  Final State at CDF

abstract:
  This thesis presents the evidence, at 3.08 sigma, for the associate
production of massive vector bosons (W and Z) in a final state with one lepton,
MET and HF-tagged jets, measured with the complete CDF II dataset (9.4fb^-1 of
data). The signals, both inclusive diboson production and WW vs WZ/ZZ
separately, were extracted from the invariant mass distribution,
M_inv(jet1,jet2), of single and double HF-tagged jet pairs. For single-tagged
events the b quark vs c quark discrimination was obtained by using a
bi-dimensional distribution M_inv(jet1,jet2) vs a flavor-serapator NN. The
results, consistent with the SM prediction, confirm the CDF capability of
identify a small signal in this challenging final state. In particular we also
report the previous version of this analysis, performed with a dataset of
7.5fb^-1 that was the first evidence of diboson production in lnu+HF final
state at a hadron collider. Beyond the pure testing of SM predicted processes,
several of the techniques developed for this thesis were also applied to the WH
search at CDF, with a relevant improvement of the sensitivity to this process.


title: Deformations of Koszul Artin-Schelter Gorenstein algebras

abstract:
  We compute the Nakayama automorphism of a PBW-deformation of a Koszul
Artin-Schelter Gorenstein algebra of finite global dimension, and give a
criterion for an augmented PBW-deformation of a Koszul Calabi-Yau algebra to be
Calabi-Yau. The relations between the Calabi-Yau property of augmented
PBW-deformations and that of non-augmented cases are discussed. The Nakayama
automorphisms of PBW-deformations of Koszul Artin-Schelter Gorenstein algebras
of global dimensions 2 and 3 are given explicitly. We show that if a
PBW-deformation of a graded Calabi-Yau algebra is still Calabi-Yau, then it is
defined by a potential under some mild conditions. Some classical results are
also recovered. Our main method used in this paper is elementary and based on
linear algebra. The results obtained in this paper will be applied in a
subsequent paper.


title: Asymptotics of a class of integrals

abstract:
  Consider an integral $I(s):=\int_0^T e^{-s(x^2-icx)}dx$, where $c>0$ and
$T>0$ are arbitrary positive constants. It is proved that $I(s)\sim
\frac{i}{sc}$ as $s\to +\infty$. The asymptotic behavior of the integral
$J(s):=\int_0^Te^{s(x^2+icx)}dx$ is also derived. One has $J(s)\sim
\frac{e^{sT^2+iscT}}{s(2T+ic)}$ as $s\to +\infty$.


title:
Evolution and the period-luminosity relation for red supergiants in the
  Magellanic Clouds

abstract:
  Excitation of radial pulsations in red supergiants of Magellanic Clouds is
investigated using the stellar evolution calculations and the self-consistent
solution of the equations of radiation hydrodynamics and turbulent convection.
The stars with initial masses 6M_odot<=M_zams<=28 M_odot and the initial
chemical composition X=0.7, 0.004<=Z<=0.008 are shown to be unstable against
fundamental mode oscillations with periods from 17 to 1200 days as they become
helium burning red supergiants. The period-luminosity relation slightly depends
on the mass loss rate varying with a factor of three, whereas its dependence on
the metal abundance is delta M_bol=0.89 delta log Z. In comparison with
galactic red supergiants (Z=0.02) the low metal abundances in red supergiants
of Magellanic Clouds are responsible for their higher effective temperatures
and substantially narrower ranges of evolutionary stellar radius change during
helium burning. Therefore on the period-mass diagram the red supergiants of
Magellanic Clouds are located within the strip with width of delta log M =
0.09, so that the uncertainty of mass evaluation of the red supergiant with the
known pulsational period is nearly 25%.


title:
Lambek vs. Lambek: Functorial Vector Space Semantics and String Diagrams
  for Lambek Calculus

abstract:
  The Distributional Compositional Categorical (DisCoCat) model is a
mathematical framework that provides compositional semantics for meanings of
natural language sentences. It consists of a computational procedure for
constructing meanings of sentences, given their grammatical structure in terms
of compositional type-logic, and given the empirically derived meanings of
their words. For the particular case that the meaning of words is modelled
within a distributional vector space model, its experimental predictions,
derived from real large scale data, have outperformed other empirically
validated methods that could build vectors for a full sentence. This success
can be attributed to a conceptually motivated mathematical underpinning, by
integrating qualitative compositional type-logic and quantitative modelling of
meaning within a category-theoretic mathematical framework.
  The type-logic used in the DisCoCat model is Lambek's pregroup grammar.
Pregroup types form a posetal compact closed category, which can be passed, in
a functorial manner, on to the compact closed structure of vector spaces,
linear maps and tensor product. The diagrammatic versions of the equational
reasoning in compact closed categories can be interpreted as the flow of word
meanings within sentences. Pregroups simplify Lambek's previous type-logic, the
Lambek calculus, which has been extensively used to formalise and reason about
various linguistic phenomena. The apparent reliance of the DisCoCat on
pregroups has been seen as a shortcoming. This paper addresses this concern, by
pointing out that one may as well realise a functorial passage from the
original type-logic of Lambek, a monoidal bi-closed category, to vector spaces,
or to any other model of meaning organised within a monoidal bi-closed
category. The corresponding string diagram calculus, due to Baez and Stay, now
depicts the flow of word meanings.


title:
The weight distributions of some cyclic codes with three or four
  nonzeros over F3

abstract:
  Because of efficient encoding and decoding algorithms, cyclic codes are an
important family of linear block codes, and have applications in communica-
tion and storage systems. However, their weight distributions are known only
for a few cases mainly on the codes with one or two nonzeros. In this paper,
the weight distributions of two classes of cyclic codes with three or four
nonzeros are determined.