title:
Synthesis of thin silicon dioxide layers with high E' center densities
  and investigation of the E' center spin relaxation dynamics for single spin
  readout applications

abstract:
  Methods for the creation of thin amorphous silicon dioxide (aSiO2) layers on
crystalline silicon substrates with very high densities of silicon dangling
bonds (so called E' centers) have been explored and volume densities of [E']>
5x10^18 cm-3 throughout a 60nm thick film have been demonstrated by exposure of
a thermal oxide layer to a low pressure Argon radio frequency plasma. While the
generated high E' center densities can be annealed completely at 300C, they are
comparatively stable at room temperature with a half life of about one month.
Spin relaxation time measurements of these states between T = 5K and T = 70K
show that the phase relaxation time T2 does not strongly depend on temperature
and compared to SiO2 films of lower E' density, is significantly shortened. The
longitudinal relaxation time T1 ~195(5)us at room temperature is in agreement
with low-density SiO2. In contrast, T1 ~625(51)us at T = 5K is much shorter
than in films of lower E' density. These results are discussed in the context
of E' centers being used as probe spins for spin-selection rules based single
spin-readout.


title: C-symplectic poset structure on a simply connected space

abstract:
  For a field $\K$ of characteristic zero, we introduce a cohomologically
symplectic poset structure ${\mathcal P}_{\K}(X)$ on a simply connected space
$X$ from the viewpoint of $\K$-homotopy theory. It is given by the poset of
inclusions of subgroups preserving c-symplectic structures in the group
${\mathcal E}(X_{\K})$ of $\K$-homotopy classes of $\K$-homotopy
self-equivalences of $X$, which is defined by the $\K$-Sullivan model of $X$.
We observe that the height of the Hasse diagram of ${\mathcal P}_{\K}(X)$ added
by 1, denoted by c-s-${\rm depth}_{\K}(X)$, is finite and often depends on the
field $\K$. In this paper, we will give some examples of ${\mathcal
P}_{\K}(X)$.


title: A rational realization problem in Gottlieb group

abstract:
  We define the fibre-restricted Gottlieb group with respect to a fibration
$\xi :X\to E\to Y$ in CW complexes. It is a subgroup of the Gottlieb group of
$X$. When $X$ and $E$ are finite simply connected, its rationalized model is
given by the arguments of derivations of Sullivan models based on F\'{e}lix,
Lupton and Smith \cite{FLS}. We consider the realization problem of groups in a
Gottlieb group as fibre-restricted Gottlieb groups in rational homotoy theory.
Especially we define an invariant named as (Gottlieb) depth of $X$ over $Y$. In
particular, when $Y=BS^1$, it is related to the rational toral rank of $X$.


title: Analysis of Amoeba Active Contours

abstract:
  Subject of this paper is the theoretical analysis of structure-adaptive
median filter algorithms that approximate curvature-based PDEs for image
filtering and segmentation. These so-called morphological amoeba filters are
based on a concept introduced by Lerallut et al. They achieve similar results
as the well-known geodesic active contour and self-snakes PDEs. In the present
work, the PDE approximated by amoeba active contours is derived for a general
geometric situation and general amoeba metric. This PDE is structurally similar
but not identical to the geodesic active contour equation. It reproduces the
previous PDE approximation results for amoeba median filters as special cases.
Furthermore, modifications of the basic amoeba active contour algorithm are
analysed that are related to the morphological force terms frequently used with
geodesic active contours. Experiments demonstrate the basic behaviour of amoeba
active contours and its similarity to geodesic active contours.


title:
Silicon strip prototypes for the Phase-II upgrade of the ATLAS tracker
  for the HL-LHC

abstract:
  This paper describes the integration structures for the silicon strips
tracker of the ATLAS detector proposed for the Phase-II upgrade of the Large
Hadron Collider (LHC), also referred to as High Luminosity LHC (HL-LHC). In
this proposed detector Silicon strip sensors are arranged in highly modular
structures, called `staves' and `petals'. This paper presents performance
results from the latest prototype stave built at Berkeley. This new,
double-sided prototype is composed of a specialized core structure, in which a
shield-less bus tape is embedded in between carbon fiber lay-ups. A detailed
description of the prototype and its electrical performance are discussed in
detail.


title:
Convergence of the discrete variance swap in time-homogeneous diffusion
  models

abstract:
  In stochastic volatility models based on time-homogeneous diffusions, we
provide a simple necessary and sufficient condition for the discretely sampled
fair strike of a variance swap to converge to the continuously sampled fair
strike. It extends Theorem 3.8 of Jarrow, Kchia, Larsson and Protter (2013) and
gives an affirmative answer to a problem posed in this paper in the case of 3/2
stochastic volatility model. We also give precise conditions (not based on
asymptotics) when the discrete fair strike of the variance swap is higher than
the continuous one and discuss the convex order conjecture proposed by
Keller-Ressel and Griessler (2012) in this context.


title:
Technical report: Functional Constraint Extraction From Register
  Transfer Level for ATPG

abstract:
  We proposed in "Functional Constraint Extraction From Register Transfer Level
for ATPG" that is currently submitted to TVLSI, an automatic functional
constraint extractor that can be applied on the RT level. These functional
constraints are used to generate pseudo functional test patterns with ATPG
tools. The patterns are then used to improve the verification process. This
technical report complements the work proposed as it contains the
implementation details of the proposed methodology and shows the detailed
intermediate and final results of the application of this methodology on a
concrete example.


title:
Robust Adaptive Beamforming Algorithms Based on the Constrained Constant
  Modulus Criterion

abstract:
  We present a robust adaptive beamforming algorithm based on the worst-case
criterion and the constrained constant modulus approach, which exploits the
constant modulus property of the desired signal. Similarly to the existing
worst-case beamformer with the minimum variance design, the problem can be
reformulated as a second-order cone (SOC) program and solved with interior
point methods. An analysis of the optimization problem is carried out and
conditions are obtained for enforcing its convexity and for adjusting its
parameters. Furthermore, low-complexity robust adaptive beamforming algorithms
based on the modified conjugate gradient (MCG) and an alternating optimization
strategy are proposed. The proposed low-complexity algorithms can compute the
existing worst-case constrained minimum variance (WC-CMV) and the proposed
worst-case constrained constant modulus (WC-CCM) designs with a quadratic cost
in the number of parameters. Simulations show that the proposed WC-CCM
algorithm performs better than existing robust beamforming algorithms.
Moreover, the numerical results also show that the performances of the proposed
low-complexity algorithms are equivalent or better than that of existing robust
algorithms, whereas the complexity is more than an order of magnitude lower.


title:
Selective-Resonance-Based Quantum Entangling Operation on Qubits in
  Circuit QED

abstract:
  We present a fast quantum entangling operation on superconducting qubits
assisted by a resonator in the quasi-dispersive regime with a new effect ---
the selective resonance coming from the amplified qubit-state-dependent
resonator transition frequency and the tunable period relation between a wanted
quantum Rabi oscillation and an unwanted one. This operation does not require
any kind of drive fields and the interaction between qubits. More interesting,
the non-computational third excitation states of the charge qubits can play an
important role in shortening largely the operation time of the entangling
gates. All those features provide an effective way to realize much faster
quantum entangling gates on superconducting qubits than previous proposals.


title:
A new approach to Kazhdan-Lusztig theory of type B via quantum symmetric
  pairs

abstract:
  We show that Hecke algebra of type B and a coideal subalgebra of the type A
quantum group satisfy a double centralizer property, generalizing the
Schur-Jimbo duality in type A. The quantum group of type A and its coideal
subalgebra form a quantum symmetric pair. A new theory of canonical bases
arising from quantum symmetric pairs is initiated. It is then applied to
formulate and establish for the first time a Kazhdan-Lusztig theory for the BGG
category O of the ortho-symplectic Lie superalgebras $\mathfrak{osp}(2m+1|2n)$.
In particular, our approach provides a new formulation of the Kazhdan-Lusztig
theory for Lie algebras of type B/C.


title: Pure Subspaces, Generalizing the Concept of Pure Spinors

abstract:
  The concept of pure spinor is generalized, giving rise to the notion of pure
subspaces, spinorial subspaces associated to isotropic vector subspaces of
non-maximal dimension. Several algebraic identities concerning the pure
subspaces are proved here, as well as some differential results. Furthermore,
the freedom in the choice of a spinorial connection is exploited in order to
relate twistor equation to the integrability of maximally isotropic
distributions.


title: Rational toral rank of a map

abstract:
  Let $X$ and $Y$ be simply connected CW complexes with finite rational
cohomologies. The rational toral rank $r_0(X)$ of a space $X$ is the largest
integer $r$ such that the torus $T^r$ can act continuously on a CW-complex in
the rational homotopy type of $X$ with all its isotropy subgroups finite
\cite{H}. As a rational homotopical condition to be a toral map preserving
almost free toral actions for a map $f:X\to Y$, we define the rational toral
rank $r_0(f)$ of $f$, which is a natural invariant with $r_0(id_X)=r_0(X)$ for
the identity map $id_X$ of $X$. We will see some properties of it by Sullivan
models, which is a free commutative differential graded algebra over $\Q$
\cite{FHT}.


title:
Macroscopic electromagnetic response of metamaterials with toroidal
  resonances

abstract:
  Toroidal dipole, first described by Ia. B. Zeldovich [Sov. Phys. JETP 33,
1184 (1957)], is a distinct electromagnetic excitation that differs both from
the electric and the magnetic dipoles. It has a number of intriguing
properties: static toroidal nuclear dipole is responsible for parity violation
in atomic spectra; interactions between static toroidal dipole and oscillating
magnetic dipole are claimed to violate Newton's Third Law while non-stationary
charge-current configurations involving toroidal multipoles have been predicted
to produce vector potential in the absence of electromagnetic fields. Existence
of the toroidal response in metamaterials was recently demonstrated and is now
a growing field of research. However, no direct analytical link has yet been
established between the transmission and reflection of macroscopic
electromagnetic media and toroidal dipole excitations. To address this
essential gap in electromagnetic theory we have developed an analytical
approach linking microscopic and macroscopic electromagnetic response of a
metamaterial and showed, using a case study, the key role of the toroidal
dipole in shaping the electromagnetic properties of the metamaterial.


title: Periodic migration in a physical model of cells on micropatterns

abstract:
  We extend a model for the morphology and dynamics of a crawling eukaryotic
cell to describe cells on micropatterned substrates. This model couples cell
morphology, adhesion, and cytoskeletal flow in response to active stresses
induced by actin and myosin. We propose that protrusive stresses are only
generated where the cell adheres, leading to the cell's effective confinement
to the pattern. Consistent with experimental results, simulated cells exhibit a
broad range of behaviors, including steady motion, turning, bipedal motion, and
periodic migration, in which the cell crawls persistently in one direction
before reversing periodically. We show that periodic motion emerges naturally
from the coupling of cell polarization to cell shape by reducing the model to a
simplified one-dimensional form that can be understood analytically.


title: Neutrino Experiments and the LHC: Friends Across 14 Orders of Magnitude

abstract:
  This proceeding explores some of the questions that connect the LHC and
neutrino experiments: What is the origin of mass? What is the meaning of
flavor? Is there direct evidence of new forces or particles? The neutrino
program investigating these questions is large and diverse. The strategy here,
to narrow the discussion, is to focus on relatively new ideas for experiments
that may be less known within the LHC community.


title: Resonating-valence-bond liquid in low dimensions

abstract:
  The Hubbard model in $D$ dimensions, with the on-site repulsion $U$ and the
transfer integral between nearest neighbors $-t/\sqrt{D}$, is studied on the
basis of the Kondo-lattice theory. If $U/|t| \gg 1$, $|n - 1| \lesssim
|t|/(DU)$, where $n$ is the number of electrons per unit cell, and $D$ is so
small that $|J|/D \gg k_{\rm B}T_c$, where $J = -4t^2/U$ and $T_c$ is $0 {\rm
K}$ for $D = 1$ and is the highest critical temperature among possible ones for
$D \ge 2$, a low-$T$ phase where $T_c < T \ll |J|/(k_{\rm B}D)$ is a frustrated
electron liquid. Since the liquid is stabilized by the Kondo effect in
conjunction with the resonating-valence-bond (RVB) mechanism, it is simply the
RVB electron liquid; in one dimension, it is also the Tomonaga-Luttinger
liquid. The Kondo energy of the RVB liquid is $k_{\rm B}T_{\rm K} = O(|J|/D)$;
its effective Fermi energy is $O(k_{\rm B}T_{\rm K})$. A midband appears on the
chemical potential between the upper and lower Hubbard bands; the Hubbard gap
is a pseudogap. As regards the density of states per unit cell of the midband,
its bandwidth is $O(k_{\rm B}T_{\rm K})$ or $O(|J|/D)$, its peak height is
$O(1/U)$, and its spectral weight is $O[t^2/(DU^2)]$. Since the midband almost
disappears in the Heisenberg limit, the RVB electron liquid in the Heisenberg
limit is simply the RVB spin liquid. The RVB electron and spin liquids
adiabatically continue to each other. Since local moments form in a high-$T$
phase where $T \gtrsim T_{\rm K}$, the high-$T$ phase is simply the Mott
insulator.


title: An information measure for comparing top $k$ lists

abstract:
  Comparing the top $k$ elements between two or more ranked results is a common
task in many contexts and settings. A few measures have been proposed to
compare top $k$ lists with attractive mathematical properties, but they face a
number of pitfalls and shortcomings in practice. This work introduces a new
measure to compare any two top k lists based on measuring the information these
lists convey. Our method investigates the compressibility of the lists, and the
length of the message to losslessly encode them gives a natural and robust
measure of their variability. This information-theoretic measure objectively
reconciles all the main considerations that arise when measuring
(dis-)similarity between lists: the extent of their non-overlapping elements in
each of the lists; the amount of disarray among overlapping elements between
the lists; the measurement of displacement of actual ranks of their overlapping
elements.


title: Comparing the White Dwarf Cooling Sequences in 47 Tuc and NGC 6397

abstract:
  Using deep Hubble Space Telescope imaging, color-magnitude diagrams are
constructed for the globular clusters 47 Tuc and NGC 6397. As expected, because
of its lower metal abundance, the main sequence of NGC 6397 lies well to the
blue of that of 47 Tuc. A comparison of the white dwarf cooling sequences of
the two clusters, however, demonstrates that these sequences are
indistinguishable over most of their loci - a consequence of the settling out
of heavy elements in the dense white dwarf atmosphere and the near equality of
their masses. Lower quality data on M4 continues this trend to a third cluster
whose metallicity is intermediate between these two. While the path of the
white dwarfs in the color-magnitude diagram is nearly identical in 47 Tuc and
NGC 6397, the numbers of white dwarfs along the path are not. This results from
the relatively rapid relaxation in NGC 6397 compared to 47 Tuc and provides a
cautionary note that simply counting objects in star clusters in random
locations as a method of testing stellar evolutionary theory is likely
dangerous unless dynamical considerations are included.


title: On the constrained growth of complex scale-independent systems

abstract:
  Scale independence is a ubiquitous feature of complex systems which implies a
highly skewed distribution of resources with no characteristic scale. Research
has long focused on why systems as varied as protein networks, evolution and
stock actions all feature scale independence. Assuming that they simply do, we
focus here on describing how this behaviour emerges, in contrast to more
idealized models usually considered. We arrive at the conjecture that a minimal
model to explain the growth towards scale independence involves only two
coupled dynamical features: the first is the well-known preferential attachment
principle and the second is a general form of delayed temporal scaling. While
the first is sufficient, the second is present in all studied data and appears
to maximize the speed of convergence to true scale independence. The delay in
this temporal scaling acts as a coupling between population growth and
individual activity. Together, these two dynamical properties appear to pave a
precise evolution path, such that even an instantaneous snapshot of a
distribution is enough to reconstruct the past of the system and predict its
future. We validate our approach and confirm its usefulness on diverse spheres
of human activities ranging from scientific and artistic productivity, to
sexual relations and online traffic.


title:
On the Groups and Automorphism Groups of the Groups of order 64p without
  a Normal Sylow p-Subgroup

abstract:
  The groups of order 64p without a normal sylow p-subgroup are listed, and
their automorphism groups are also determined. As a by-product of our original
effort to get these groups, we needed to determine the automorphism groups of
those groups of order 64 with an odd-order automorphism. In view of the fact
that we already had determined these groups and that these automorphism groups
are not given explicitly in the literature, we have appended to this report
these automorphism groups. In another project we were looking for new complete
groups by following automorphism group towers up to completion when the
computer memory allowed such followups. We did this for these groups of order
64. In another appendix we give the results of this work as applied to the
groups of order 64.


title: Physical Properties of UDF12 Galaxies in Cosmological simulations

abstract:
  We have performed a large cosmological hydrodynamics simulation tailored to
the deep survey with the Hubble Space Telescope made in 2012, the so-called
UDF12 campaign. After making a light-cone output, we have applied the same
color selection criteria as the UDF12 campaign to select galaxies from our
simulation, and then, have examined the physical properties of them as a proxy
of the real observed UDF12 galaxies at $z > 7$. As a result, we find that the
halo mass is almost linearly proportional to the observed ultraviolet (UV)
luminosity ($4 \times 10^{11}~{\rm M_{\odot}}$ at $M_{\rm UV} = -21$). The dust
attenuation and UV slope $\beta$ well correlates with the observed UV
luminosity, which is consistent with observations quantitatively. The star
formation rate (SFR) is also linearly proportional to the stellar mass and the
specific SFR shows only a weak dependency on the mass. We also find an
increasing star formation history with a time-scale of $\sim100$ Myr in the
high-$z$ galaxies. An average metallicity weighted by the Lyman continuum
luminosity reaches up to $>0.1$ Solar even at $z \sim 10$, suggesting a rapid
metal enrichment. We also expect $\geq 0.1$ mJy at 350 GHz of the dust thermal
emission from the galaxies with $H_{160} \leq 27$, which can be detectable with
the Atacama Large Milimetre-submilimetre Array. The galaxies selected by the
UDF12 survey contribute to only $52--12\%$ of the cosmic SFR density from $z
\sim 7$ to $z \sim 10$, respectively. The James Webb Space Telescope will push
the detection fraction up to $77--72\%$.


title: Interstellar dust properties of M51 from AKARI mid-infrared images

abstract:
  Using mid-infrared (MIR) images of four photometric bands of the Infrared
Camera (IRC) onboard the AKARI satellite, S7 (7 um), S11 (11 um), L15 (15 um),
and L24 (24 um), we investigate the interstellar dust properties of the nearby
pair of galaxies M51 with respect to its spiral arm structure. The arm and
interarm regions being defined based on a spatially filtered stellar component
model image, we measure the arm-to-interarm contrast for each band. The
contrast is lowest in the S11 image, which is interpreted as that among the
four AKARI MIR bands the S11 image best correlates with the spatial
distribution of dust grains including colder components, while the L24 image
with the highest contrast traces warmer dust heated by star forming activities.
The surface brightness ratio between the bands, i.e. color, is measured over
the disk of the main galaxy, M51a, at 300 pc resolution. We find that the
distribution of S7/S11 is smooth and well traces the global spiral arm pattern
while L15/S11 and L24/S11 peak at individual HII regions. This result indicates
that the ionization state of PAHs is related to the spiral structure.
Comparison with observational data and dust models also supports the importance
of the variation in the PAH ionization state within the M51a disk. However, the
mechanism driving this variation is not yet clear from currently available data
sets. Another suggestion from the comparison with the models is that the PAH
fraction to the total dust mass is higher than previously estimated.


title: An Overview on 3GPP Device-to-Device Proximity Services

abstract:
  Device-to-device (D2D) communication will likely be added to LTE in 3GPP
Release 12. In principle, exploiting direct communication between nearby mobile
devices will improve spectrum utilization, overall throughput, and energy
consumption, while enabling new peer-to-peer and location-based applications
and services. D2D-enabled LTE devices can also become competitive for fallback
public safety networks, that must function when cellular networks are not
available, or fail. Introducing D2D poses many challenges and risks to the
long-standing cellular architecture, which is centered around the base station.
We provide an overview on D2D standardization activities in 3GPP, identify
outstanding technical challenges, draw lessons from initial evaluation studies,
and summarize "best practices" in the design of a D2D-enabled air interface for
LTE-based cellular networks.


title:
Transient Orthogonality Catastrophe in a Time Dependent Nonequilibrium
  Environment

abstract:
  We study the response of a highly-excited time dependent quantum many-body
state to a sudden local perturbation, a sort of orthogonality catastrophe
problem in a transient non-equilibrium environment. To this extent we consider,
as key quantity, the overlap between time dependent wave-functions, that we
write in terms of a novel two-time correlator generalizing the standard
Loschmidt Echo. We discuss its physical meaning, general properties, and its
connection with experimentally measurable quantities probed through
non-equilibrium Ramsey interferometry schemes. Then we present explicit
calculations for a one dimensional interacting Fermi system brought out of
equilibrium by a sudden change of the interaction, and perturbed by the
switching on of a local static potential. We show that different scattering
processes give rise to remarkably different behaviors at long times, quite
opposite from the equilibrium situation. In particular, while the forward
scattering contribution retains its power law structure even in the presence of
a large non-equilibrium perturbation, with an exponent that is strongly
affected by the transient nature of the bath, the backscattering term is a
source of non-linearity which generates an exponential decay in time of the
Loschmidt Echo, reminiscent of an effective thermal behavior.


title:
More on cosmological constraints on spontaneous R-symmetry breaking
  models

abstract:
  We study the spontaneous R-symmetry breaking model and investigate the
cosmological constraints on this model due to the pseudo Nambu-Goldstone boson,
R-axion. We consider the R-axion which has relatively heavy mass in order to
complement our previous work. In this regime, model parameters, R-axions mass
and R-symmetry breaking scale, are constrained by Big Bang Nucleosynthesis and
overproduction of the gravitino produced from R-axion decay and thermal plasma.
We find that the allowed parameter space is very small for high reheating
temperature. For low reheating temperature, the U(1)_R breaking scale f_a is
constrained as f_a<10^{12-14}GeV regardless of the value of R-axion mass.


title: A Data-Driven Method of Background Prediction at NOvA

abstract:
  NOvA is a long-baseline neutrino oscillation experiment that will use the
NuMI beam originating at Fermilab. NOvA enables the study of two oscillation
channels: $\nu_{\mu}$ disappearance and $\nu_{e}$ appearance. It consists of
two functionally identical detectors, the near detector (ND) at Fermilab and
the far detector (FD) near International Falls in Northern Minnesota. The ND
will be used to study the neutrino beam spectrum and composition before
oscillation, and measure background rate to the $\nu_e$ appearance search. In
this paper, I describe a data-driven technique to estimate the neutral current
(NC) component of the ND spectrum. Using the $\nu_{\mu}$ CC interactions where
the reconstructed muon is removed from the event, we produce a well understood
sample of hadronic showers that resemble NC interactions.


title: Covering sets for limited-magnitude errors

abstract:
  For a set
  $\cM=\{-\mu,-\mu+1,\ldots, \lambda\}\setminus\{0\}$ with non-negative
integers $\lambda,\mu<q$ not both 0, a subset $\cS$ of the residue class ring
$\Z_q$ modulo an integer $q\ge 1$ is called a $(\lambda,\mu;q)$-\emph{covering
set} if $$ \cM \cS=\{ms \bmod q : m\in \cM,\ s\in \cS\}=\Z_q. $$ Small covering
sets play an important role in codes correcting limited-magnitude errors. We
give an explicit construction of a $(\lambda,\mu;q)$-covering set $\cS$ which
is of the size $q^{1 + o(1)}\max\{\lambda,\mu\}^{-1/2}$ for almost all integers
$q\ge 1$ and of optimal size $p\max\{\lambda,\mu\}^{-1}$ if $q=p$ is prime.
Furthermore, using a bound on the fourth moment of character sums of Cochrane
and Shi we prove the bound $$\omega_{\lambda,\mu}(q)\le
q^{1+o(1)}\max\{\lambda,\mu\}^{-1/2},$$ for any integer $q\ge 1$, however the
proof of this bound is not constructive.


title: On involutions and generalized symmetric spaces of dicyclic groups

abstract:
  Let $G=\Dc_{n}$ be the dicyclic group of order $4n$. Let $\varphi$ be an
automorphism of $G$ of order $k$. We describe $\varphi$ and the generalized
symmetric space $Q$ of $G$ associated with $\varphi$. When $\varphi$ is an
involution, we describe its fixed point group $H=G^{\varphi}$ along with the
$H$-orbits and $G$-orbits of $Q$ corresponding to the action of
$\varphi$-twisted conjugation.


title: BPS Wilson Loop T-dual to Spinning String in AdS5xS5

abstract:
  We use the string sigma model action in AdS_5 \times S^5 to reconstruct the
open string solution ending on the Wilson loop in S^3\times R parametrized by a
geometric angle in S^3 and an angle in flavor space. Under the interchange of
the world sheet space and time coordinates and the T-duality transformation
with the radial inversion, the static open string configuration associated with
the BPS Wilson loop with two equal angle parameters becomes a long open
spinning string configuration which is produced by taking the equal limit of
two frequencies for the folded spinning closed string with two spins in AdS_5
\times S^5.


title:
Pitchfork Bifurcation and Zharov Splitting in Nonlinear Mid-infrared
  Photothermal Spectroscopy in a liquid crystal using a Quantum Cascade Laser

abstract:
  We report on the mid-infrared nonlinear photothermal spectrum of the neat
liquid crystal 4-Octyl-4'-Cyanobiphenyl (8CB) using a tunable Quantum Cascade
Laser (QCL). The nonequilibrium steady state characterized by the nonlinear
photothermal infrared response undergoes a supercritical pitchfork bifurcation.
The bifurcation, observed in heterodyne two-color pump-probe detection, leads
to ultrasharp nonlinear infrared spectra similar to those reported in the
visible region. A systematic study of the peak splitting as function of
absorbed infrared power shows the bifurcation has a critical exponent of 0.5.
The surprising observation of an apparently universal critical exponent in a
nonequilibrium state is explained using a simple model reminiscent of mean
field theory. Apart from the intrinsic interest for nonequilibrium studies,
nonlinear photothermal methods lead to a dramatic narrowing of spectral lines,
giving rise to a potential new contrast mechanism for the rapidly emerging new
field of mid-infrared microspectroscopy using QCLs.


title:
Valence Fluctuations in the Extended Periodic Anderson Model at Finite
  Temperatures

abstract:
  We study valence fluctuation at finite temperatures in the periodic Anderson
model with the Coulomb interaction between $f$ and conduction electons,
combining dynamical mean-field theory with the non-crossing approximation. It
is found that a large Coulomb repulsion induces a first-order valence
transition. The finite temperature phase diagram is determined.


title:
Coherent Scattering Investigations at the Spallation Neutron Source: a
  Snowmass White Paper

abstract:
  The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory,
Tennessee, provides an intense flux of neutrinos in the few tens-of-MeV range,
with a sharply-pulsed timing structure that is beneficial for background
rejection. In this white paper, we describe how the SNS source can be used for
a measurement of coherent elastic neutrino-nucleus scattering (CENNS), and the
physics reach of different phases of such an experimental program (CSI:
Coherent Scattering Investigations at the SNS).


title:
Nonequilibrium transport through a quantum dot coupled to normal and
  superconducting leads

abstract:
  We study the interacting quantum dot coupled to the normal and
superconducting leads by means of a continuous-time quantum Monte Carlo method
in the Keldysh-Nambu formalism. Deducing the steady current through the quantum
dot under a finite voltage, we examine how the gap magnitude in the
superconducting lead and the interaction strength at the quantum dot affect
transport properties. It is clarified that the Andreev reflection and Kondo
effect lead to nonmonotonic behavior in the nonequilibrium transport at zero
temperature.


title:
Cluster mean-field approach with density matrix renormalization group:
  Application to the hard-core bosonic Hubbard model on a triangular lattice

abstract:
  We introduce a new numerical method for the solution of self-consistent
equations in the cluster mean-field theory. The method uses the density matrix
renormalization group method to solve the associated cluster problem. We obtain
an accurate critical value of the supersolid-superfluid transitions in the
hard-core bosonic Hubbard model on a triangular lattice, which is comparable
with the recent quantum Monte Carlo results. This algorithm is applicable to
more general classes of models with a larger number of degrees of freedom.


title: Dual Affine invariant points

abstract:
  An affine invariant point on the class of convex bodies in R^n, endowed with
the Hausdorff metric, is a continuous map p which is invariant under one-to-one
affine transformations A on R^n, that is, p(A(K))=A(p(K)).
  We define here the new notion of dual affine point q of an affine invariant
point p by the formula q(K^{p(K)})=p(K) for every convex body K, where K^{p(K)}
denotes the polar of K with respect to p(K).
  We investigate which affine invariant points do have a dual point, whether
this dual point is unique and has itself a dual point. We define a product on
the set of affine invariant points, in relation with duality.
  Finally, examples are given which exhibit the rich structure of the set of
affine invariant points.


title: The squashed entanglement of a quantum channel

abstract:
  This paper defines the squashed entanglement of a quantum channel as the
maximum squashed entanglement that can be registered by a sender and receiver
at the input and output of a quantum channel, respectively. A new subadditivity
inequality for the original squashed entanglement measure of Christandl and
Winter leads to the conclusion that the squashed entanglement of a quantum
channel is an additive function of a tensor product of any two quantum
channels. More importantly, this new subadditivity inequality, along with prior
results of Christandl, Winter, et al., establishes the squashed entanglement of
a quantum channel as an upper bound on the quantum communication capacity of
any channel assisted by unlimited forward and backward classical communication.
A similar proof establishes this quantity as an upper bound on the private
capacity of a quantum channel assisted by unlimited forward and backward public
classical communication. This latter result is relevant as a limitation on
rates achievable in quantum key distribution. As an important application, we
determine that these capacities can never exceed log((1+eta)/(1-eta)) for a
pure-loss bosonic channel for which a fraction eta of the input photons make it
to the output on average. The best known lower bound on these capacities is
equal to log(1/(1-eta)). Thus, in the high-loss regime for which eta << 1, this
new upper bound demonstrates that the protocols corresponding to the above
lower bound are nearly optimal.


title:
Dimensional Crossover in Quasi-one-dimensional Spin-1 Heisenberg
  Antiferromagnets

abstract:
  We study the quenching of the Haldane gap in quasi-one-dimensional systems of
weakly coupled spin-1 antiferromagnetic Heisenberg chains. The critical
interchain coupling Jc required to stabilize long range magnetic order can be
accurately determined from large scale quantum Monte Carlo calculations.
Several different geometries of coupled chains are studied, illustrating the
dependence of Jc on the coordination of chains. For bipartite geometries,
ferromagnetically coupled chains yield similar magnitudes for Jc.


title: Astrophysics of Bertrand Space-times

abstract:
  We construct a model for galactic dark matter that arises as a solution of
Einstein gravity, and is a Bertrand space-time matched with an external
Schwarzschild metric. This model can explain galactic rotation curves. Further,
we study gravitational lensing in these space-times, and in particular we
consider Einstein rings, using the strong lensing formalism of Virbhadra and
Ellis. Our results are in good agreement with observational data, and indicate
that under certain conditions, gravitational lensing effects from galactic dark
matter may be similar to that from Schwarzschild backgrounds.


title:
The 4-error linear complexity distribution for $2^n$-periodic binary
  sequences

abstract:
  By using the sieve method of combinatorics, we study $k$-error linear
complexity distribution of $2^n$-periodic binary sequences based on Games-Chan
algorithm. For $k=4,5$, the complete counting functions on the $k$-error linear
complexity of $2^n$-periodic balanced binary sequences (with linear complexity
less than $2^n$) are presented. As a consequence of the result, the complete
counting functions on the 4-error linear complexity of $2^n$-periodic binary
sequences (with linear complexity $2^n$ or less than $2^n$) are obvious.
Generally, the complete counting functions on the $k$-error linear complexity
of $2^n$-periodic binary sequences can be obtained with a similar approach.


title:
Online Performance Optimization of a DC Motor Driving a Variable Pitch
  Propeller

abstract:
  A practical online optimization scheme is developed for performance
optimization of an electrical aircraft propulsion system. The goal is to
minimize the power extraction of the propulsion system for any given thrust
value. The online optimizer computes the optimum pitch angle of a variable
pitch propeller by minimizing the power of the system for a command thrust
value. This algorithm is tested on a DC motor driving a variable pitch
propeller; the experimental hardware setup of the DC motor along with its
variable pitch propeller is also described. Experimental results show the
efficiency and practicality of the proposed online optimization scheme.
Outstanding issues are sketched.


title:
Observation of a Geometric Hall Effect in a Spinor Bose-Einstein
  Condensate with a Skyrmion Spin Texture

abstract:
  For a spin-carrying particle moving in a spatially varying magnetic field,
effective electromagnetic forces can arise due to the geometric phase
associated with adiabatic spin rotation of the particle. We report the
observation of a geometric Hall effect in a spinor Bose-Einstein condensate
with a skyrmion spin texture. Under translational oscillations of the spin
texture, the condensate resonantly develops a circular motion in a harmonic
trap, demonstrating the existence of an effective Lorentz force. When the
condensate circulates, quantized vortices are nucleated in the boundary region
of the condensate and the vortex number increases over 100 without significant
heating. We attribute the vortex nucleation to the shearing effect of the
effective Lorentz force from the inhomogeneous effective magnetic field.


title: Magnetization plateaus in generalized Shastry-Sutherland models

abstract:
  We study an anisotropic Heisenberg antiferromagnet with ferromagnetic
transverse spin exchange using exact quantum Monte Carlo methods. Such a model
is relevant to a class of rare earth tetraboride materials that display a range
of magnetization plateaus under applied magnetic field. The layered arrangement
of magnetic ions in these materials is topologically equivalent to the
Shastry-Sutherland lattice. In this frustrated geometry, we study the interplay
of next-nearest neighbor interactions in stabilizing a plateau at half the
saturation magnetization (or 1/2 plateau). We also show hysteresis-like
behavior at the onset of the 1/3 plateau.


title: Graphene nanoribbon based spaser

abstract:
  A novel type of spaser with the net amplification of surface plasmons (SPs)
in doped graphene nanoribbon is proposed. The plasmons in THz region can be
generated in a dopped graphene nanoribbon due to nonradiative excitation by
emitters like two level quantum dots located along a graphene nanoribbon. The
minimal population inversion per unit area, needed for the net amplification of
SPs in a doped graphene nanoribbon is obtained. The dependence of the minimal
population inversion on the surface plasmon wavevector, graphene nanoribbon
width, doping and damping parameters necessary for the amplification of surface
plasmons in the armchair graphene nanoribbon is studied.


title:
Impurity scattering in Weyl Semimetals and their stability
  classification

abstract:
  Weyl Semimetals (WS) are a new class of Dirac-type materials exhibiting a
phase with bulk energy nodes and an associated vanishing density of states
(DOS). We investigate the stability of this nodal DOS suppression in the
presence of local impurities and consider whether or not such a suppression can
be lifted by impurity-induced resonances. We find that while a scalar (chemical
potential type) impurity can always induce a resonance at arbitrary energy and
hence lift the DOS suppression at Dirac/Weyl nodes, for many other impurity
types (e.g. magnetic or orbital-mixing), resonances are forbidden in a wide
range of energy. We investigate a $4$-band tight-binding model of WS adapted
from a physical heterostructure construction due to Burkov, Hook, and Balents,
and represent a local impurity potential by a strength $g$ as well as a matrix
structure $\Lambda$. A general framework is developed to analyze this resonance
dichotomy and make connection with the phase shift picture in scattering
theory, as well as to determine the relation between resonance energy and
impurity strength $g$. A complete classification of impurities based on
$\Lambda$, based on their effect on nodal DOS suppression, is tabulated. We
also discuss the differences between continuum and lattice approaches.


title:
How Plasma Composition affects the relativistic flows and the emergent
  spectra

abstract:
  It has been recently shown that transonic electron positron fluid is the
least relativistic, compared to the fluid containing finite proportion of
baryons. We compute spectra from these flows in general relativity (GR)
including the effect of light bending. We consider the bremsstrahlung process
to supply the seed photons. We choose accretion in the advective domain, and
for simplicity the radial accretion or Bondi type accretion. We show that
electron positron accreting flow produces the softest spectra and the lowest
luminosity.


title: Group Classification of a generalization of the Heath Equation

abstract:
  The complete group classification of a generalization of the Heath model is
carried out by connecting it to the heat equation with nonlinear source.
Examples of invariant solutions are given under the terminal and the barrier
option condition.


title:
Measurements of VV Boson Production And Self-Interactions in The
  Semileptonic Channel at CMS

abstract:
  We present a summary of the latest measurements of the VV crosssections,
where V=W or Z and one of the bosons decays into a pair of jets while the other
decays leptonically. The data sample(s) correspond to proton-proton collision
events collected with the CMS detector at sqrt{s} = 7 TeV. Subsequent searches
for Anomalous Triple Gauge couplings, which allow us to probe the non-Abelian
structure in the Electroweak Sector, are described. We present the exclusion
limits on the corresponding couplings.


title:
Hopping over Big Data: Accelerating Ad-hoc OLAP Queries with Grasshopper
  Algorithms

abstract:
  This paper presents a family of algorithms for fast subset filtering within
ordered sets of integers representing composite keys. Applications include
significant acceleration of (ad-hoc) analytic queries against a data warehouse
without any additional indexing. The algorithms work for point, range and set
restrictions on multiple attributes, in any combination, and are inherently
multidimensional. The main idea consists in intelligent combination of
sequential crawling with jumps over large portions of irrelevant keys. The way
to combine them is adaptive to characteristics of the underlying data store.


title: Theory of supercurrent transport in SIsFS Josephson junctions

abstract:
  We present the results of theoretical study of Current-Phase Relations (CPR)
in Josephson junctions of SIsFS type, where 'S' is a bulk superconductor and
'IsF' is a complex weak link consisting of a superconducting film 's', a
metallic ferromagnet 'F' and an insulating barrier 'I'. We calculate the
relationship between Josephson current and phase difference. At temperatures
close to critical, calculations are performed analytically in the frame of the
Ginsburg-Landau equations. At low temperatures numerical method is developed to
solve selfconsistently the Usadel equations in the structure. We demonstrate
that SIsFS junctions have several distinct regimes of supercurrent transport
and we examine spatial distributions of the pair potential across the structure
in different regimes. We study the crossover between these regimes which is
caused by shifting the location of a weak link from the tunnel barrier 'I' to
the F-layer. We show that strong deviations of the CPR from sinusoidal shape
occur even in a vicinity of Tc, and these deviations are strongest in the
crossover regime. We demonstrate the existence of temperature-induced crossover
between 0 and pi states in the contact and show that smoothness of this
transition strongly depends on the CPR shape.


title: Observing Galactic Black Hole Sources in Hard X-rays

abstract:
  Observations of Galactic black hole sources are traditionally done in the
classical X-ray range (2 -- 10 keV) due to sensitivity constraints. Most of the
accretion power, however, is radiated above 10 keV and the study of these
sources in hard X-rays has the potential to unravel the radiation mechanisms
operating at the inner region of the accretion disk, which is believed to be
the seat of a myriad of fascinating features like jet emission, high frequency
QPO emission etc. I will briefly summarise the long term hard X-ray
observational features like spectral state identification, state transitions
and hints of polarised emission, and describe the new insights that would be
provided by the forthcoming Astrosat satellite, particularly emphasising the
contributions expected from the CZT-Imager payload.


title:
Effect of the flow composition on outflow rates from accretion discs
  around black holes

abstract:
  We studied the outflow behaviour from accretion discs around black holes
taking into account the vertical equilibrium accretion flow model. The outflow
rate is found to depend crucially on flow composition. Our approach is to study
the outflow behaviour as function of inflow around black holes with an equation
of state which allows flow to be thermally relativistic close to black holes
and non relativistic far away from black holes. We studied shock ejection
model. A pure electron positron pair flow never undergoes shock transition
while presence of some baryons (common in outflows and jets) makes it possible
to have standing shock waves in the flow. It can be concluded that the presence
of protons is necessary for the flow to show the outflow behaviour. The outflow
rate is maximum when the flow contains the proton number density which is 27%
of the electron number density. We conclude that a pure electron-positron jet
is unlikely to form.


title:
Optimal Routing and Scheduling of Charge for Electric Vehicles: Case
  Study

abstract:
  In Colombia, there is an increasing interest about improving public
transportation. One of the proposed strategies in that way is the use battery
electric vehicles (BEVs). One of the new challenges is the BEVs routing
problem, which is subjected to the traditional issues of the routing problems,
and must also consider the particularities of autonomy, charge and battery
degradation of the BEVs. In this work, a scheme that coordinates the routing,
scheduling of charge and operating costs of BEVs is proposed. The simplified
operating costs have been modeled considering both charging fees and battery
degradation. A case study is presented, in order to illustrate the proposed
methodology. The given case considers an airport shuttle service scenario, in
which energy consumption of the BEVs is estimated based on experimentally
measured driving patterns.


title:
Evidence for A Parsec-scale Jet from The Galactic Center Black Hole:
  Interaction with Local Gas

abstract:
  Despite strong physical reasons that they should exist and decades of search,
jets from the Galactic Center Black Hole, Sgr A*, have not yet been
convincingly detected. Based on high-resolution Very Large Array images and
ultra-deep imaging-spectroscopic data produced by the Chandra X-ray
Observatory, we report new evidence for the existence of a parsec-scale jet
from Sgr A*, by associating a linear feature G359.944-0.052, previously
identified in X-ray images of the Galactic Center, with a radio shock front on
the Eastern Arm of the Sgr A West HII region. We show that the shock front can
be explained in terms of the impact of a jet having a sharp momentum peak along
the Galaxy's rotation axis, whereas G359.944-0.052, a quasi-steady feature with
a power-law spectrum, can be understood as synchrotron radiation from
shock-induced ultrarelativistic electrons cooling in a finite post-shock region
downstream along the jet path. Several interesting implications of the jet
properties are discussed.


title:
Search for anomalous production of events with same-sign dileptons and b
  jets in 14.3 fb^-1 of pp collisions at sqrt(s) = 8 TeV with the ATLAS
  detector

abstract:
  A search is presented for exotic processes that result in final states
containing jets including at least one b jet, sizable missing transverse
momentum, and a pair of leptons with the same electric charge. Using a sample
of 14.3 fb^-1 of pp collisions at sqrt(s) =8 TeV recorded by the ATLAS detector
at the Large Hadron Collider, no significant excess of events over the
background expectation is observed. This observation is interpreted as
constraining several signal hypotheses beyond the Standard Model and limits are
set at 95% confidence level on relevant parameters of the signal hypotheses.


title:
The Strain Derivatives of $T_c$ in HgBa$_2$CuO$_{4+\delta}$: CuO$_2$
  Plane Alone is Not Enough

abstract:
  The strain derivatives of $T_c$ along the $a$ and $c$ axes have been
determined for HgBa$_2$CuO$_{4+\delta}$ (Hg1201), the simplest monolayer
cuprate with the highest $T_c$ of all monolayer cuprates ($T_c$ = 97 K at
optimal doping). The underdoped compound with the initial $T_c$ of 65 K has
been studied as a function of pressure up to 20 GPa by magnetic susceptibility
and X-ray diffraction (XRD). The observed linear increase in $T_c$ with
pressure is the same as previously been found for the optimally-doped compound.
The above results have enabled the investigation of the origins of the
significantly different $T_c$ values of optimally doped Hg1201 and the
well-studied compound La$_{2-x}$Sr$_{x}$CuO$_{4}$ (LSCO), the latter value of
$T_c$ = 40 K being only about 40% of the former. Hg1201 can have almost
identical CuO$_6$ octahedra as LSCO if specifically strained. When the apical
and in-plane CuO$_2$ distances are the same for the two compounds, a large
discrepancy in their $T_c$ remains. Differences in crystal structures and
interactions involving the Hg-O charge reservoir layers of Hg1201 may be
responsible for the different $T_c$ values exhibited by the two compounds.


title:
40 Years of Variable Stars: A Celebration of Contributions by Horace A.
  Smith

abstract:
  This online book contains the proceedings of a meeting held at Michigan State
University to celebrate the career and contributions of Horace A Smith. The
meeting focused on the areas of astronomy which Horace worked on over the years
and featured talks on RR Lyrae, Cepheids, and other variable stars. In addition
to the direct links to the arXiv articles, I have included a link to download
the entire book for free.


title: Stability

abstract:
  Reproducibility is imperative for any scientific discovery. More often than
not, modern scientific findings rely on statistical analysis of
high-dimensional data. At a minimum, reproducibility manifests itself in
stability of statistical results relative to "reasonable" perturbations to data
and to the model used. Jacknife, bootstrap, and cross-validation are based on
perturbations to data, while robust statistics methods deal with perturbations
to models. In this article, a case is made for the importance of stability in
statistics. Firstly, we motivate the necessity of stability for interpretable
and reliable encoding models from brain fMRI signals. Secondly, we find strong
evidence in the literature to demonstrate the central role of stability in
statistical inference, such as sensitivity analysis and effect detection.
Thirdly, a smoothing parameter selector based on estimation stability (ES),
ES-CV, is proposed for Lasso, in order to bring stability to bear on
cross-validation (CV). ES-CV is then utilized in the encoding models to reduce
the number of predictors by 60% with almost no loss (1.3%) of prediction
performance across over 2,000 voxels. Last, a novel "stability" argument is
seen to drive new results that shed light on the intriguing interactions
between sample to sample variability and heavier tail error distribution (e.g.,
double-exponential) in high-dimensional regression models with $p$ predictors
and $n$ independent samples. In particular, when
$p/n\rightarrow\kappa\in(0.3,1)$ and the error distribution is
double-exponential, the Ordinary Least Squares (OLS) is a better estimator than
the Least Absolute Deviation (LAD) estimator.


title: Excluding a Generic Spin-2 Higgs Impostor

abstract:
  We argue that the current experimental data in conjunction with perturbative
unitarity considerations exclude the possibility that the LHC 125-126 GeV
resonance is a generic massive spin-2 particle of either parity. We analyse
tree-level Z-spin-2 elastic scattering and demonstrate that perturbative
unitarity breaks down at energies $\Lambda\sim 600$ GeV. Furthermore, we find
that W,Z-spin-2 interactions contribute to the electroweak oblique parameters
in a way that is in gross disagreement with observations.


title: Managing and Analysing Software Product Line Requirements

abstract:
  Modelling software product line (SPL) features plays a crucial role to a
successful development of SPL. Feature diagram is one of the widely used
notations to model SPL variants. However, there is a lack of precisely defined
formal notations for representing and verifying such models. This paper
presents an approach that we adopt to model SPL variants by using UML and
subsequently verify them by using first-order logic. UML provides an overall
modelling view of the system. First-order logic provides a precise and rigorous
interpretation of the feature diagrams. We model variants and their
dependencies by using propositional connectives and build logical expressions.
These expressions are then validated by the Alloy verification tool. The
analysis and verification process is illustrated by using Computer Aided
Dispatch (CAD) system.


title: Self-gravitational Interaction in z = 4 Horava-Lifshitz Gravity

abstract:
  Motivated by recent works [1,2], the influences of self-gravitational
interaction on the Hawking radiation are studied both for (3 + 1) and (4 + 1)
dimensional black holes in $z = 4$ Ho\u{r}ava-Lifshitz gravity. It is found
that the tunneling entropies $S_{B(3 + 1)}$ and $S_{B(4 + 1)}$ independent on
particle's mass are consistent with the thermodynamical entropies $S_{BH(3 +
1)}$ and $S_{BH(4 + 1)}$, respectively. There is a very visible degree of
uniformity between thermodynamics and quantum tunneling in $z = 4$
Ho\u{r}ava-Lifshitz gravity. It suggests that the entropies contained corrected
terms could be explained well by the self-gravitational interaction of Hawking
radiation. The study of tunneling process may shed light on understanding the
Ho\u{r}ava-Lifshitz gravity.


title: Incoherence-Optimal Matrix Completion

abstract:
  This paper considers the matrix completion problem. We show that it is not
necessary to assume joint incoherence, which is a standard but unintuitive and
restrictive condition that is imposed by previous studies. This leads to a
sample complexity bound that is order-wise optimal with respect to the
incoherence parameter (as well as to the rank $r$ and the matrix dimension $n$
up to a log factor). As a consequence, we improve the sample complexity of
recovering a semidefinite matrix from $O(nr^{2}\log^{2}n)$ to $O(nr\log^{2}n)$,
and the highest allowable rank from $\Theta(\sqrt{n}/\log n)$ to
$\Theta(n/\log^{2}n)$. The key step in proof is to obtain new bounds on the
$\ell_{\infty,2}$-norm, defined as the maximum of the row and column norms of a
matrix. To illustrate the applicability of our techniques, we discuss
extensions to SVD projection, structured matrix completion and semi-supervised
clustering, for which we provide order-wise improvements over existing results.
Finally, we turn to the closely-related problem of low-rank-plus-sparse matrix
decomposition. We show that the joint incoherence condition is unavoidable here
for polynomial-time algorithms conditioned on the Planted Clique conjecture.
This means it is intractable in general to separate a rank-$\omega(\sqrt{n})$
positive semidefinite matrix and a sparse matrix. Interestingly, our results
show that the standard and joint incoherence conditions are associated
respectively with the information (statistical) and computational aspects of
the matrix decomposition problem.


title:
Residual Symmetry Reductions and Interaction Solutions of
  (2+1)-Dimensional Burgers Equation

abstract:
  The (2+1)-dimensional Burgers equation has been investigated first from
prospective of symmetry by localizing the nonlocal residual symmetries and then
studied by a simple generalized tanh expansion method. New symmetry reduction
solutions has been obtained by using the standard Lie point symmetry group
approach. A new B\"{a}klund transformation for Burgers equation has been given
with the generalized tanh expansion method . From this BT, interactive
solutions among different nonlinear excitations which is hard to obtain by
other methods has also been obtained easily.


title: How Empty are Disk Gaps Opened by Giant Planets?

abstract:
  Gap clearing by giant planets has been proposed to explain the optically thin
cavities observed in many protoplanetary disks. How much material remains in
the gap determines not only how detectable young planets are in their birth
environments, but also how strong corotation torques are, which impacts how
planets can survive fast orbital migration. We determine numerically how the
average surface density inside the gap, sigma_gap, depends on planet-to-star
mass ratio q, Shakura-Sunyaev viscosity parameter alpha, and disk
height-to-radius aspect ratio h/r. Our results are derived from our new
GPU-accelerated Lagrangian hydrodynamical code PEnGUIn, and are verified by
independent simulations with ZEUS90. For Jupiter-like planets, we find
sigma_gap \propto q^-2.2 alpha^1.4 (h/r)^6.6, and for near brown dwarf masses,
sigma_gap \propto q^-1 alpha^1.3 (h/r)^6.1. Surface density contrasts inside
and outside gaps can be as large as 10^4, even when the planet does not
accrete. We derive a simple analytic scaling, sigma_gap \propto q^-2 alpha^1
(h/r)^5, that compares reasonably well to empirical results, especially at low
Neptune-like masses, and use discrepancies to highlight areas for progress.


title:
TREPS: A Monte-Carlo Event Generator for Two-photon Processes at
  $e^+e^-$ Colliders using an Equivalent Photon Approximation

abstract:
  A description and the use of an event-generator code for two-photon processes
at e+e- colliders, TREPS, are presented. This program uses an equivalent photon
approximation in which the virtuality of photons is taken into account. It is
applicable to various processes by specifying a combination of final-state
particles and the angular distributions among them. A comparison of the results
with those from other programs is also given.


title:
A singular initial-boundary value problem for nonlinear wave equations
  and holography in asymptotically anti-de Sitter spaces

abstract:
  We analyze the initial value problem for semilinear wave equations on
asymptotically anti-de Sitter spaces using energy methods adapted to the
geometry of the problem at infinity. The key feature is that the coefficients
become strongly singular at infinity, which leads to considering nontrivial
data on the conformal boundary of the manifold. This question arises in Physics
as the holographic prescription problem in string theory.


title: Scalar filed evolution and area spectrum for Lovelock-AdS black holes

abstract:
  We study the modes of evolution of massless scalar fields in the
asymptotically AdS spacetime surrounding maximally symmetric black holes of
large and intermediate size in the Lovelock model. It is observed that all
modes are purely damped at higher orders. Also, the rate of damping is seen to
be independent of order at higher dimensions. The asymptotic form of these
frequencies for the case of large black holes is found analytically. Finally,
the area spectrum for such black holes is found from these asymptotic modes.


title:
Modern Summation Methods for Loop Integrals in Quantum Field Theory: The
  Packages Sigma, EvaluateMultiSums and SumProduction

abstract:
  A large class of Feynman integrals, like e.g., two-point parameter integrals
with at most one mass and containing local operator insertions, can be
transformed to multi-sums over hypergeometric expressions. In this survey
article we present a difference field approach for symbolic summation that
enables one to simplify such definite nested sums to indefinite nested sums. In
particular, the simplification is given -if possible- in terms of harmonic
sums, generalized harmonic sums, cyclotomic harmonic sums or binomial sums.
Special emphasis is put on the developed packages Sigma, EvaluateMultiSums and
SumProduction that assist in the task to perform these simplifications
completely automatically for huge input expressions.


title: Numerical method for the stochastic projected Gross-Pitaevskii equation

abstract:
  We present a method for solving the stochastic projected Gross-Pitaevskii
equation (SPGPE) for a three-dimensional Bose gas in a harmonic-oscillator
trapping potential. The SPGPE contains the challenge of both accurately
evolving all modes in the low energy classical region of the system, and
evaluating terms from the number-conserving scattering reservoir process. We
give an accurate and efficient procedure for evaluating the scattering terms
using a Hermite-polynomial based spectral-Galerkin representation, which allows
us to precisely implement the low energy mode restriction. Stochastic
integration is performed using the weak semi-implicit Euler method. We
extensively characterize the accuracy of our method, finding a faster than
expected rate of stochastic convergence. Physical consistency of the algorithm
is demonstrated by considering thermalization of initially random states.


title: SDO/AIA Observations of a Partially Erupting Prominence

abstract:
  We report an observation of a partially erupting prominence and associated
dynamical plasma processes based on observations recorded by the Atmospheric
Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO). The
prominence first goes through a slow rise (SR) phase followed by a fast rise
(FR). The slow rise phase started after a couple of small brightenings seen
toward the footpoints. At the turning point from SR to FR, the prominence had
already become kinked. The prominence shows strong brightening at the central
kink location during the start of FR. We interpret this as internal magnetic
reconnection occurring at a vertical current sheet forming between the two legs
of the erupting prominence (flux-rope). The brightening at the central kink
location is seen in all the EUV channels of AIA. The contributions of
differential emission at higher temperatures are larger compared to that for
typical coronal temperatures supporting a reconnection scenario at the central
kink location. The plasma above the brightening location gets ejected as a hot
plasmoid-like structure embedded in a CME, and those below drain down in the
form of blobs moving towards the Sun's surface. The unique time resolution of
the AIA has allowed all of these eruptive aspects, including SR-to-FR, kinking,
central current sheet formation, plasmoid-like eruption, and filament
"splitting", to be observed in a single event, providing strong and
comprehensive evidence in favour of the model of partially erupting flux ropes.


title: The elliptic model for social fluxes

abstract:
  In this paper, a model (called the elliptic model) is proposed to estimate
the number of social ties between two locations using population data in a
similar manner to how transportation research deals with trips. To overcome the
asymmetry of transportation models, the new model considers that the number of
relationships between two locations is inversely proportional to the population
in the ellipse whose foci are in these two locations. The elliptic model is
evaluated by considering the anonymous communications patterns of 25 million
users from three different countries, where a location has been assigned to
each user based on their most used phone tower or billing zip code. With this
information, spatial social networks are built at three levels of resolution:
tower, city and region for each of the three countries. The elliptic model
achieves a similar performance when predicting communication fluxes as
transportation models do when predicting trips. This shows that human
relationships are influenced at least as much by geography as is human
mobility.


title: NLO thermal dilepton rate at non-zero momentum

abstract:
  The vector channel spectral function and the dilepton production rate from a
QCD plasma at a temperature above a few hundred MeV are evaluated up to
next-to-leading order (NLO) including their dependence on a non-zero momentum
with respect to the heat bath. The invariant mass of the virtual photon is
taken to be in the range K^2 ~ (pi T)^2 ~ (1 GeV)^2, generalizing previous NLO
results valid for K^2 >> (pi T)^2. In the opposite regime 0 < K^2 << (pi T)^2
the loop expansion breaks down, but agrees nevertheless in order of magnitude
with a previous result obtained through resummations. Ways to test the vector
spectral function through comparisons with imaginary-time correlators measured
on the lattice are discussed.


title:
Benchmarking the Bayesian reconstruction of the non-perturbative heavy
  $Q\bar{Q}$ potential

abstract:
  The extraction of the finite temperature heavy quark potential from lattice
QCD relies on a spectral analysis of the real-time Wilson loop. Through its
position and shape, the lowest lying spectral peak encodes the real and
imaginary part of this complex potential. We benchmark this extraction strategy
using leading order hard-thermal loop (HTL) calculations. I.e. we analytically
calculate the Wilson loop and determine the corresponding spectrum. By fitting
its lowest lying peak we obtain the real- and imaginary part and confirm that
the knowledge of the lowest peak alone is sufficient for obtaining the
potential. We deploy a novel Bayesian approach to the reconstruction of
spectral functions to HTL correlators in Euclidean time and observe how well
the known spectral function and values for the real and imaginary part are
reproduced. Finally we apply the method to quenched lattice QCD data and
perform an improved estimate of both real and imaginary part of the
non-perturbative heavy $Q\bar{Q}$ potential.


title:
Error bounds and exponential improvements for the asymptotic expansions
  of the gamma function and its reciprocal

abstract:
  In (Boyd, Proc. R. Soc. Lond. A 447 (1994) 609--630), W. G. C. Boyd derived a
resurgence representation for the gamma function, exploiting the reformulation
of the method of steepest descents by M. Berry and C. Howls (Berry and Howls,
Proc. R. Soc. Lond. A 434 (1991) 657--675). Using this representation, he was
able to derive a number of properties of the asymptotic expansion for the gamma
function, including explicit and realistic error bounds, the smooth transition
of the Stokes discontinuities, and asymptotics for the late coefficients. The
main aim of this paper is to modify the resurgence formula of Boyd making it
suitable for deriving better error estimates for the asymptotic expansions of
the gamma function and its reciprocal. We also prove the exponentially improved
versions of these expansions complete with error terms. Finally, we provide new
(formal) asymptotic expansions for the coefficients appearing in the asymptotic
series and compare their numerical efficacy with the results of earlier
authors.


title: Effective gravitational interactions of dark matter axions

abstract:
  We investigate the structure of gravitational self-interactions of coherently
oscillating axions in the general relativistic framework. A generic action for
a massive scalar field in the Friedmann-Robertson-Walker background is first
introduced based on the effective field theory approach to cosmological
perturbations. Using the obtained setup, we evaluate the effective
gravitational interaction of the massive scalar field, i.e. scalar quartic
interactions mediated by metric perturbations. Applying the results to the
system of dark matter axions, we estimate their self-interaction rate and
discuss its implications for the axion Bose-Einstein condensate dark matter
scenario. Leading contributions for the gravitational interactions of axions
are given by the process mediated by the dynamical graviton field, which is
essentially the Newtonian potential induced by fluctuations of the background
fluids. We find that it leads to the same order of magnitude for the
interaction rate of dark matter axions in the condensed regime, compared with
the results of previous studies using the Newtonian approximation.


title: Asymmetries in Coronal Spectral lines and Emission Measure Distribution

abstract:
  It has previously been argued that 1. spicules do not provide enough
pre-heated plasma to fill the corona, and 2. even if they did, additional
heating would be required to keep the plasma hot as it expands upward. We here
address the question of whether spicules play an important role by injecting
plasma at cooler temperatures ($< 2$ MK), which then gets heated to coronal
values at higher altitudes. We measure red-blue asymmetries in line profiles
formed over a wide range of temperatures in the bright moss areas of two active
regions. We derive emission measure distributions from the excess wing
emission. We find that the asymmetries and emission measures are small and
conclude that spicules do not inject an important (dominant) mass flux into the
cores of active regions at temperatures $> 0.6$ MK ($\log T > 5.8$). These
conclusions apply not only to spicules, but to any process that suddenly heats
and accelerates chromospheric plasma (e.g., a chromospheric nanoflare). The
traditional picture of coronal heating and chromospheric evaporation appears to
remain the most likely explanation of the active region corona.


title:
Isoscalar Giant Resonance Strengths in $^{32}$S and possible excitations
  of superdeformed and $^{28}$Si + $\alpha$ cluster bandheads

abstract:
  Isoscalar giant resonances and low spin states in $^{32}$S have been measured
with inelastic $\alpha$ scattering at extremely forward angles including zero
degrees at E$_{\alpha}$ = 386 MeV. By applying the multipole decomposition
analysis, various excited states are classified according to their spin and
parities (J$^{\pi}$), and are discussed in relation to the super deformed and
$^{28}$Si + $\alpha$ cluster bands.


title:
Stabilizing a novel hexagonal Ru2C through Lifshitz transition under
  pressure

abstract:
  A new type of heavy transition metal carbide (TMC), Ru2C with a space group
of p3 - m1(164) was synthesized experimentally at high pressurehigh temperature
[J Phys. Condens. Matter. 2012 Sep 12; 24(36): 362202.] and it was consequently
quenched to ambient condition. We have carried out the dynamical stability
study, which reveals the instability at ambient condition. The effect of
pressure has been taken into consideration in order to stabilize as the
reported synthesizing condition. We have found that it can be stabilized from
30 GPa to 110 GPa. The stronger 4d -2p hybridization and the formation of a
cage like Fermi surface do impact the stability and also illustrates a Lifshitz
transition. We have also found a mixed 4d-2p bands crossing the Fermi level
form a Fermi surface piece at {\Gamma} point under pressure. The freshly
appearing bands provide a tunnel for quantum transportation and it reduces the
density of states at Fermi level, which further stabilizes the lattice under
pressure.


title: Object Detection Using Keygraphs

abstract:
  We propose a new framework for object detection based on a generalization of
the keypoint correspondence framework. This framework is based on replacing
keypoints by keygraphs, i.e. isomorph directed graphs whose vertices are
keypoints, in order to explore relative and structural information. Unlike
similar works in the literature, we deal directly with graphs in the entire
pipeline: we search for graph correspondences instead of searching for
individual point correspondences and then building graph correspondences from
them afterwards. We also estimate the pose from graph correspondences instead
of falling back to point correspondences through a voting table. The
contributions of this paper are the proposed framework and an implementation
that properly handles its inherent issues of loss of locality and combinatorial
explosion, showing its viability for real-time applications. In particular, we
introduce the novel concept of keytuples to solve a running time issue. The
accuracy of the implementation is shown by results of over 800 experiments with
a well-known database of images. The speed is illustrated by real-time tracking
with two different cameras in ordinary hardware.


title: Constructing semisimple subalgebras of real semisimple Lie algebras

abstract:
  We consider the problem of constructing semisimple subalgebras of real
(semi-) simple Lie algebras. We develop computational methods that help to deal
with this problem. Our methods boil down to solving a set of polynomial
equations. In many cases the equations turn out to be sufficiently "pleasant"
to be able to solve them. In particular this is the case for S-subalgebras.


title: The True Title of Bayes's Essay

abstract:
  New evidence is presented that Richard Price gave Thomas Bayes's famous essay
a very different title from the commonly reported one. It is argued that this
implies Price almost surely and Bayes not improbably embarked upon this work
seeking a defensive tool to combat David Hume on an issue in theology.


title: Distances on the tropical line determined by two points

abstract:
  Let $p',q'\in R^n$. Write $p'\sim q'$ if $p'-q'$ is a multiple of
$(1,\ldots,1)$. Two different points $p$ and $q$ in $R^n/\sim$ uniquely
determine a tropical line $L(p,q)$, passing through them, and stable under
small perturbations. This line is a balanced unrooted semi--labeled tree on $n$
leaves. It is also a metric graph.
  If some representatives $p'$ and $q'$ of $p$ and $q$ are the first and second
columns of some real normal idempotent order $n$ matrix $A$, we prove that the
tree $L(p,q)$ is described by a matrix $F$, easily obtained from $A$. We also
prove that $L(p,q)$ is caterpillar. We prove that every vertex in $L(p,q)$
belongs to the tropical linear segment joining $p$ and $q$. A vertex, denoted
$pq$, closest (w.r.t tropical distance) to $p$ exists in $L(p,q)$. Same for
$q$. The distances between pairs of adjacent vertices in $L(p,q)$ and the
distances $\dd(p,pq)$, $\dd(qp,q)$ and $\dd(p,q)$ are certain entries of the
matrix $|F|$. In addition, if $p$ and $q$ are generic, then the tree $L(p,q)$
is trivalent. The entries of $F$ are differences (i.e., sum of principal
diagonal minus sum of secondary diagonal) of order 2 minors of the first two
columns of $A$.


title:
Bridging planets and stars using scaling laws in anelastic spherical
  shell dynamos

abstract:
  Dynamos operating in the interiors of rapidly rotating planets and low-mass
stars might belong to a similar category where rotation plays a vital role. We
quantify this similarity using scaling laws. We analyse direct numerical
simulations of Boussinesq and anelastic spherical shell dynamos. These dynamos
represent simplified models which span from Earth-like planets to rapidly
rotating low-mass stars. We find that magnetic field and velocity in these
dynamos are related to the available buoyancy power via a simple power law
which holds over wide variety of control parameters.


title:
Linear Spin Wave Analysis for General Magnetic Orders in the Kondo
  Lattice Model

abstract:
  We extend the formulation of the spin wave theory for the Kondo lattice
model, which was mainly used for the ferromagnetic metallic state, to general
magnetic orders including complex noncollinear and noncoplanar orders. The 1/S
expansion is reformulated in the matrix form depending on the size of the
magnetic unit cell. The noncollinearity and noncoplanarity of the localized
moments are properly taken into account by the matrix elements of the
para-unitary matrix used in the diagonalization of the Bogoliubov-de Gennes
type Hamiltonian for magnons. We apply the formulation within the linear spin
wave approximation to a typical noncollinear case, the $120^{\circ}$ N{\'e}el
order on a triangular lattice at half filling. We calculate the magnon
excitation spectrum and the quantum correction to the magnitude of ordered
moments as functions of the strength of the Hund's-rule coupling, $J_{\rm
H}/t$. We find that the magnon excitation shows softening at $J_{\rm H}/t
\simeq 2.9$, which indicates that the $120^{\circ}$ order is destabilized for
smaller $J_{\rm H}/t$. On the other hand, we show that the $120^{\circ}$ order
is stable in the entire range of $J_{\rm H}/t \gtrsim 2.9$, and, in the limit
of $J_{\rm H}/t \to \infty$, the form of the spin wave spectrum approaches that
for the antiferromagnetic Heisenberg model, while the bandwidth is proportional
to $t^2/J_{\rm H}$. The reduction of the ordered moment is smaller than that
for the spin-only model, except in the vicinity of the softening.


title: Combinatorial Auctions without Money

abstract:
  Algorithmic Mechanism Design attempts to marry computation and incentives,
mainly by leveraging monetary transfers between designer and selfish agents
involved. This is principally because in absence of money, very little can be
done to enforce truthfulness. However, in certain applications, money is
unavailable, morally unacceptable or might simply be at odds with the objective
of the mechanism. For example, in Combinatorial Auctions (CAs), the
paradigmatic problem of the area, we aim at solutions of maximum social welfare
but still charge the society to ensure truthfulness. Additionally, truthfulness
of CAs is poorly understood already in the case in which bidders happen to be
interested in only two different sets of goods.
  We focus on the design of incentive-compatible CAs without money in the
general setting of $k$-minded bidders. We trade monetary transfers with the
observation that the mechanism can detect certain lies of the bidders: i.e., we
study truthful CAs with verification and without money. We prove a
characterization of truthful mechanisms, which makes an interesting parallel
with the well-understood case of CAs with money for single-minded bidders. We
then give a host of upper bounds on the approximation ratio obtained by either
deterministic or randomized truthful mechanisms when the sets and valuations
are private knowledge of the bidders. (Most of these mechanisms run in
polynomial time and return solutions with (nearly) best possible approximation
guarantees.) We complement these positive results with a number of lower bounds
(some of which are essentially tight) that hold in the easier case of public
sets. We thus provide an almost complete picture of truthfully approximating
CAs in this general setting with multi-dimensional bidders.


title: Dynamic Gomory-Hu Tree Construction -- fast and simple

abstract:
  A cut tree (or Gomory-Hu tree) of an undirected weighted graph G=(V,E)
encodes a minimum s-t-cut for each vertex pair {s,t} \subseteq V and can be
iteratively constructed by n-1 maximum flow computations. They solve the
multiterminal network flow problem, which asks for the all-pairs maximum flow
values in a network and at the same time they represent n-1 non-crossing,
linearly independent cuts that constitute a minimum cut basis of G. Hence, cut
trees are resident in at least two fundamental fields of network analysis and
graph theory, which emphasizes their importance for many applications. In this
work we present a fully-dynamic algorithm that efficiently maintains a cut tree
for a changing graph. The algorithm is easy to implement and has a high
potential for saving cut computations under the assumption that a local change
in the underlying graph does rarely affect the global cut structure. We
document the good practicability of our approach in a brief experiment on real
world data.


title:
Kochen-Specker Sets with a Mixture of 16 Rank-1 and 14 Rank-2 Projectors
  for a Three-Qubit System

abstract:
  Kochen-Specker (KS) theorem denies the possibility for the noncontextual
hidden variable theories to reproduce the predictions of quantum mechanics. A
set of projection operators (projectors) and bases used to show the
impossibility of noncontextual definite values assignment is named as the KS
set. Since one KS set with a mixture of 16 rank-1 projectors and 14 rank-2
projectors proposed in 1995 [Kernaghan M and Peres A 1995 Phys. Lett.\ A
\textbf{198} 1] for a three-qubit system, there are plenty of the same type KS
sets and we propose a systematic way to produce them. We also propose a
probabilistic state-dependent proof of the KS theorem that mainly focuses on
the values assignment for all the rank-2 projectors.


title:
Hybrid Boltzmann Gross-Pitaevskii Theory of Bose-Einstein Condensation
  and Superfluidity in Open Driven-Dissipative Systems

abstract:
  We derive a theoretical model which describes Bose-Einstein condensation in
an open driven-dissipative system. It includes external pumping of a thermal
reservoir, finite life time of the condensed particles and energy relaxation.
The coupling between the reservoir and the condensate is described with
semi-classical Boltzmann rates. This results in a dissipative term in the
Gross-Pitaevskii equation for the condensate, which is proportional to the
energy of the elementary excitations of the system. We analyse the main
properties of a condensate described by this hybrid Boltzmann Gross-Pitaevskii
model, namely, dispersion of the elementary excitations, bogolon distribution
function, first order coherence, dynamic and energetic stability, drag force
created by a disorder potential. We find that the dispersion of the elementary
excitations of a condensed state fulfils the Landau criterion of superfluidity.
The condensate is dynamically and energetically stable as longs it moves at a
velocity smaller than the speed of excitations. First order spatial coherence
of the condensate is found to decay exponentially in 1D and with a power law in
2D, similarly with the case of conservative systems. The coherence lengths are
found to be longer due to the finite life time of the condensate excitations.
We compare these properties with the ones of a condensate described by the
popular "diffusive" models in which the dissipative term is proportional to the
local condensate density. In the latter, the dispersion of excitations is
diffusive which as soon as the condensate is put into motion implies finite
mechanical friction and can lead to an energetic instability.


title: Aspects of the planetary Birkhoff normal form

abstract:
  The discovery in [G. Pinzari. PhD thesis. Univ. Roma Tre. 2009], [L.
Chierchia and G. Pinzari, Invent. Math. 2011] of the Birkhoff normal form for
the planetary many--body problem opened new insights and hopes for the
comprehension of the dynamics of this problem. Remarkably, it allowed to give a
{\sl direct} proof of the celebrated Arnold's Theorem [V. I. Arnold. Uspehi
Math. Nauk. 1963] on the stability of planetary motions. In this paper, using a
"ad hoc" set of symplectic variables, we develop an asymptotic formula for this
normal form that may turn to be useful in applications. As an example, we
provide two very simple applications to the three-body problem: we prove a
conjecture by [V. I. Arnold. cit] on the "Kolmogorov set"of this problem and,
using Nehoro{\v{s}}ev Theory [Nehoro{\v{s}}ev. Uspehi Math. Nauk. 1977], we
prove, in the planar case, stability of all planetary actions over
exponentially-long times, provided mean--motion resonances are excluded. We
also briefly discuss perspectives and problems for full generalization of the
results in the paper.


title:
Probabilistic Approach to Fractional Integrals and the
  Hardy-Littlewood-Sobolev Inequality

abstract:
  We give a short summary of Varopoulos' generalised Hardy-Littlewood-Sobolev
inequality for self-adjoint $C_{0}$ semigroups and give a new probabilistic
representation of the classical fractional integral operators on $\R^n$ as
projections of martingale transforms. Using this formula we derive a new proof
of the classical Hardy-Littlewood-Sobolev inequality based on Burkholder-Gundy
and Doob's inequalities for martingales.


title: The LHCb Upgrade

abstract:
  The LHCb experiment is designed to perform high-precision measurements of CP
violation and search for New Physics using the enormous flux involving beauty
and charm quarks produced at the LHC. The operation and the results obtained
from the data collected in 2010 and 2011 demonstrate that the detector is
robust and functioning very well. However, the limit of 1 fb^-1 of data per
nominal year cannot be overcome without improving the detector. We therefore
plan for an upgraded spectrometer by 2018 with a 40 MHz readout and a much more
flexible software-based triggering system that will increase the data rate as
well as the efficiency specially in the hadronic channels. Here we present the
LHCb detector upgrade plans, based on the Letter of Intent and Framework
Technical Design Report.


title: Properties of oscillatory motions in a facular region

abstract:
  We study the properties of waves in a facular region of moderate strength in
the photosphere and chromosphere. Our aim is to analyse statistically the wave
periods, power and phase relations as a function of the magnetic field strength
and inclination. Our work is based on observations obtained at the German
Vacuum Tower Telescope (Observatorio del Teide, Tenerife) using two different
instruments: the Triple Etalon SOlar Spectrometer (TESOS), in the BaII 4554 A
line to measure velocity and intensity variations through the photosphere; and,
simultaneously, the Tenerife Infrared Polarimeter (TIP-II), in the FeI 1.56 mm
lines to the measure the Stokes parameters and magnetic field strength in the
lower photosphere. Additionally, we use the simultaneous broad-band filtergrams
in the CaIIH line to obtain information about intensity oscillations in the
chromosphere. We find several clear trends in the oscillation behaviour: (i)
the period of oscillation increases by 15-20 % with the magnetic field
increasing from 500 to 1500 G; (ii) the temperature-velocity phase shifts show
a strikingly different distribution in the facular region compared to the quiet
region, a significant number of cases in the range from -180 to 180 degrees is
detected in the facula. (iii) the most powerful chromospheric CaIIH intensity
oscillations are observed at locations with strong magnetic fields (1.3-1.5 kG)
inclined by 10-12 degrees, as a result of upward propagating waves with rather
small phase speeds, and temperature-velocity phase shifts between 0 and 90
degrees; (iv) the power of the photospheric velocity oscillations from the
\BaII\ line increases linearly with decreasing magnetic field inclination,
reaching its maximum at strong field locations.


title: Exact counting of Euler Tours for Graphs of Bounded Treewidth

abstract:
  In this paper we give a simple polynomial-time algorithm to exactly count the
number of Euler Tours (ETs) of any Eulerian graph of bounded treewidth. The
problems of counting ETs are known to be #P-complete for general graphs
(Brightwell and Winkler, (Brightwell and Winkler, 2005). To date, no
polynomial-time algorithm for counting Euler tours of any class of graphs is
known except for the very special case of series-parallel graphs (which have
treewidth 2).


title: Which algebraic groups are Picard varieties?

abstract:
  We show that every connected commutative algebraic group over an
algebraically closed field of characteristic 0 is the Picard variety of some
projective variety, obtained by pinching a smooth variety along a finite
subscheme. In contrast, no Witt group of dimension at least 3 over a perfect
field of prime characteristic is isogenous to the Picard variety obtained by
this construction.


title: Quantum corrections in Galileon theories

abstract:
  We calculate the one-loop quantum corrections in the cubic Galileon theory,
using cutoff regularization. We confirm the expected form of the one-loop
effective action and that the couplings of the Galileon theory do not get
renormalized. However, new terms, not included in the tree-level action, are
induced by quantum corrections. We also consider the one-loop corrections in an
effective brane theory, which belongs to the Horndeski or generalized Galileon
class. We find that new terms are generated by quantum corrections, while the
tree-level couplings are also renormalized. We conclude that the structure of
the generalized Galileon theories is altered by quantum corrections more
radically than that of the Galileon theory.


title: Graph connection Laplacian and random matrices with random blocks

abstract:
  Graph connection Laplacian (GCL) is a modern data analysis technique that is
starting to be applied for the analysis of high dimensional and massive
datasets. Motivated by this technique, we study matrices that are akin to the
ones appearing in the null case of GCL, i.e the case where there is no
structure in the dataset under investigation. Developing this understanding is
important in making sense of the output of the algorithms based on GCL. We
hence develop a theory explaining the behavior of the spectral distribution of
a large class of random matrices, in particular random matrices with random
block entries of fixed size. Part of the theory covers the case where there is
significant dependence between the blocks. Numerical work shows that the
agreement between our theoretical predictions and numerical simulations is
generally very good.


title: Long period sdB + MS binaries with Mercator

abstract:
  The predicted orbital period distribution of the subdwarf-B (sdB) population
is bi-modal with a peak at short (< 10 days) and long (> 250 days) periods.
Observationally, many short-period sdB systems are indeed known. The predicted
long period peak is missing and orbits have only been determined for a few
long-period systems. As these predictions are based on poorly understood
binary-interaction processes, it is of prime importance to confront the
predictions to well-constrained observational data. We therefore initiated a
monitoring program to find and characterize long-period sdB stars with the 1.2
m Mercator telescope. Here we present the results of this program.


title:
State Independent Proof of Kochen-Specker Theorem with Thirty Rank-Two
  Projectors

abstract:
  The Kochen-Specker theorem states that noncontextual hidden variable theories
are incompatible with quantum mechanics. We provide a state independent proof
of the Kochen-Specker theorem using the smallest number of projectors, i.e.,
thirty rank-2 projectors, associated with the Mermin pentagram for a
three-qubit system.


title:
Finite-time blowup for a complex Ginzburg-Landau equation with linear
  driving

abstract:
  In this paper, we consider the complex Ginzburg--Landau equation $u_t =
e^{i\theta} [\Delta u + |u|^\alpha u] + \gamma u$ on ${\mathbb R}^N $, where
$\alpha >0$, $\gamma \in \R$ and $-\pi /2<\theta <\pi /2$. By convexity
arguments we prove that, under certain conditions on $\alpha ,\theta ,\gamma $,
a class of solutions with negative initial energy blows up in finite time.


title: State space collapse for critical multistage epidemics

abstract:
  We study a multistage epidemic model which generalizes the SIR model and
where infected individuals go through K>0 stages of the epidemic before being
removed. An infected individual in stage k=1,...,K may infect a susceptible
individual, who directly goes to stage k of the epidemic; or it may go to the
next stage k+1 of the epidemic. For this model, we identify the critical regime
in which we establish diffusion approximations. Surprisingly, the limiting
diffusion exhibits an unusual form of state space collapse which we analyze in
detail.


title: The chiral magnetic wave in an expanding QCD fluid

abstract:
  As a consequence of the chiral anomaly, the hydrodynamics of hot QCD matter
coupled to QED allows for a long-wavelength mode of chiral charge density, the
chiral magnetic wave (CMW), that provides for a mechanism of electric charge
separation along the direction of an external magnetic field. Here, we
investigate the efficiency of this mechanism for values of the time-dependent
magnetic field and of the energy density attained in the hot QCD matter of
ultra-relativistic heavy ion collisions. To this end, we derive the CMW
equations of motion for expanding systems by treating the CMW as a charge
perturbation on top of an expanding Bjorken-type background field in the limit
of small chemical potential. Both, approximate analytical and full numerical
solutions to these equations of motion indicate that for the lifetime and
thermodynamic conditions of ultra-relativistic heavy ion collisions, the
efficiency of CMW-induced electric charge separation decreases with increasing
center of mass energy and that the effect is numerically very small. We note,
however, that if sizable oriented asymmetries in the axial charge distribution
(that are not induced by the CMW) are present in the early fluid dynamic
evolution, then the mechanism of CMW-induced electric charge separation can be
much more efficient.


title:
A mathematical model of systemic inhibition of angiogenesis in
  metastatic development

abstract:
  We present a mathematical model describing the time development of a
population of tumors subject to mutual angiogenic inhibitory signaling. Based
on biophysical derivations, it describes organism-scale population dynamics
under the influence of three processes: birth (dissemination of secondary
tumors), growth and inhibition (through angiogenesis). The resulting model is a
nonlinear partial differential transport equation with nonlocal boundary
condition. The nonlinearity stands in the velocity through a nonlocal quantity
of the model (the total metastatic volume). The asymptotic behavior of the
model is numerically investigated and reveals interesting dynamics ranging from
convergence to a steady state to bounded non-periodic or periodic behaviors,
possibly with complex repeated patterns. Numerical simulations are performed
with the intent to theoretically study the relative impact of potentiation or
impairment of each process of the birth/growth/inhibition balance. Biological
insights on possible implications for the phenomenon of "cancer without
disease" are also discussed.


title:
On the controllability of quantum transport in an electronic
  nanostructure

abstract:
  We investigate the controllability of quantum electrons trapped in a
two-dimensional device, typically a MOS field-effect transistor. The problem is
modeled by the Schr\"odinger equation in a bounded domain coupled to the
Poisson equation for the electrical potential. The controller acts on the
system through the boundary condition on the potential, on a part of the
boundary modeling the gate. We prove that, generically with respect to the
shape of the domain and boundary conditions on the gate, the device is
controllable. We also consider control properties of a more realistic nonlinear
version of the device, taking into account the self-consistent electrostatic
Poisson potential.


title: Graphs Embedded into Finite Projective Planes

abstract:
  We introduce and study embeddings of graphs in finite projective planes, and
present related results for some families of graphs including complete graphs
and complete bipartite graphs. We also make connections between embeddings of
graphs and the existence of certain substructures in a plane, such as Baer
subplanes and arcs.


title:
Compact quantum gates on electron-spin qubits assisted by diamond
  nitrogen-vacancy centers inside cavities

abstract:
  Constructing compact quantum circuits for universal quantum gates on
solid-state systems is crucial for quantum computing. We present some compact
quantum circuits for a deterministic solid-state quantum computing, including
the CNOT, Toffoli, and Fredkin gates on the diamond nitrogen-vacancy centers
confined inside cavities, achieved by some input-output processes of a single
photon. Our quantum circuits for these universal quantum gates are simple and
economic. Moreover, additional electron qubits are not employed, but only a
single-photon medium. These gates have a long coherent time. We discuss the
feasibility of these universal solid-state quantum gates, concluding that they
are feasible with current technology.


title:
Calculations of three-nucleon reactions with N3LO chiral forces:
  achievements and challenges

abstract:
  We discuss the application of the chiral N3LO forces to three-nucleon
reactions and point to the challenges which will have to be addressed. Present
approaches to solve three-nucleon Faddeev equations are based on a partial-wave
decomposition. A rapid increase of the number of terms contributing to the
chiral three-nucleon force when increasing the order of the chiral expansion
from N2LO to N3LO forced us to develop a fast and effective method of
automatized partial wave decomposition. At low energies of the incoming nucleon
below about 20MeV, where only a limited number of partial waves is required,
this method allowed us to perform calculations of reactions in the
three-nucleon continuum using N3LO two- and three-nucleon forces. It turns out
that inclusion of consistent chiral interactions, with relativistic 1/m
corrections and short-range 2pi-contact term omitted in the N3LO three-nucleon
force, does not explain the long standing low energy Ay-puzzle. We discuss
problems arising when chiral forces are applied at higher energies, where large
three-nucleon force effects are expected. It seems plausible that at higher
energies, due to a rapid increase of a number of partial waves required to
reach convergent results, a three-dimensional formulation of the Faddeev
equations which avoids partial-wave decomposition is desirable.


title: Cycles in Projective Spaces

abstract:
  We prove that every possible $k$-cycle can be embedded into $PG(n,q)$, for
all $n\geq 3$ and $q$ a power of a prime.