title: A Double Team Semantics for Generalized Quantifiers

abstract:
  We define a semantics for first-order logic with generalized quantifiers
based on double teams. We also define and investigate a notion of a generalized
atom. Such atoms can be used in order to define extensions of first-order logic
with a team-based semantics. We also define a game semantics and compare it
with the double team semantics.


title: Subgroups generated by two Dehn twists on a nonorientable surface

abstract:
  Let a and b be two simple closed curves on an orientable surface S such that
their geometric intersection number is greater than 1. It is known that the
group generated by corresponding Dehn twists t_a and t_b is isomorphic to the
free group of rank 2. In this paper we extend this result to the case of a
nonorientable surface.


title: Physical Properties of Luminous Dust Poor Quasars

abstract:
  We identify and characterize a population of luminous dust poor quasars at
0<z<5, similar in photometric properties to the objects found at z>6
previously. This class of active galactic nuclei has been known to show little
IR emission from a dusty structure, but is yet poorly understood in terms of
number evolution or of dependence on physical quantities. In order to better
understand the luminous dust poor quasar properties, we compiled a rest-frame
UV to IR library of 41,000 optically selected type-1 quasars with
$L_{bol}>10^{45.7} erg s^{-1}$. After fitting the broad-band spectral energy
distributions (SEDs) with accretion disk and dust components, we find 0.6% of
our sample to be hot dust poor with a rest-frame 2.3 micron to 0.51 micron flux
density ratio of -0.5 dex or less. The dust poor SEDs are blue in the
UV-optical and weak in the MIR, such that their accretion disks are less
obscured, and that hot dust emission traces that of warm dust down to the dust
poor regime. At a given bolometric luminosity, dust poor quasars are lower in
black hole mass and higher in Eddington ratio than general luminous quasars,
suggesting that they are in a rapidly growing evolutionary state in which the
dust poor phase appears as a short or rare phenomenon. The dust poor fraction
increases with redshift, and possible implications for the evolution of the
dust poor fraction are discussed.


title:
Quantum electrodynamic theory of the cardiac excitation propagation I:
  construction of quantum electrodynamics in the bidomain

abstract:
  To provide a unified theoretical framework ranging from a cellular-level
excitation mechanism to organic-level geometric propagation, a new theory
inspired by quantum electrodynamic theory for light propagation is proposed by
describing the cardiac excitation propagation as the continuation of absorption
and emission of charged ions by myocardial cells. By the choice of gauge and
the membrane current density, a set of Maxwell's equations with a charge
density and a current density is constructed in macroscopic bidomain and is
shown to be equivalent to the diffusion-reaction system with the B. van der Pol
oscillator. The derived Maxwell's equations for the excitation propagation
obeys the conservational laws of the number of the cations, energy and
momentum, but the total charge is not conserved. The Lagrangian is derived to
reveal that the trajectory and wavefront of the excitation propagation are the
same as the electrodynamic wave if ion channels work uniformly. From the second
quantization, the Hamiltonian is also derived to explain the excitation
mechanism of the myocardial cell by Feynman's diagram and the mechanism of the
refractory period in the perspective of positron. The effects of the external
electromagnetic field are explained both from the action of the Lagrangian and
the interaction by the Hamiltonian.


title:
Crystallographic reconstruction study of the effects of finish rolling
  temperature on the variant selection during bainite transformation in C-Mn
  high-strength steels

abstract:
  The effect of finish rolling temperature (FRT) on the austenite- ()
to-bainite () phase transformation is quantitatively investigated in
high-strength C-Mn steels. In particular, the present study aims to clarify the
respective contributions of the conditioning during the hot rolling and the
variant selection (VS) during the phase transformation to the inherited
texture. To this end, an alternative crystallographic reconstruction procedure,
which can be directly applied to experimental electron backscatter diffraction
(EBSD) mappings, is developed by combining the best features of the existing
models: the orientation relationship (OR) refinement, the local pixel-by-pixel
analysis and the nuclei identification and spreading strategy. The
applicability of this method is demonstrated on both quenching and partitioning
(Q&P) and as-quenched lath-martensite steels. The results obtained on the C-Mn
steels confirm that the sample finish rolled at the lowest temperature
(829{\deg}C) exhibits the sharpest transformation texture. It is shown that
this sharp texture is exclusively due to a strong VS from parent brass
{110}<1-12>, S {213}<-3-64> and Goss {110}<001> grains, whereas the VS from the
copper {112}<-1-11> grains is insensitive to the FRT. In addition, a
statistical VS analysis proves that the habit planes of the selected variants
do not systematically correspond to the predicted active slip planes using the
Taylor model. In contrast, a correlation between the Bain group to which the
selected variants belong and the FRT is clearly revealed, regardless of the
parent orientation. These results are discussed in terms of polygranular
accommodation mechanisms, especially in view of the observed development in the
hot-rolled samples of high-angle grain boundaries with misorientation axes
between <111> and <110> .


title:
Comparison of time/phase lags in the hard state and plateau state of GRS
  1915+105

abstract:
  We investigate the complex behavior of energy- and frequency-dependent
time/phase lags in the plateau state and the radio-quiet hard state of GRS
1915+105. In our timing analysis, we find that when the source is faint in the
radio, QPOs are observed above 2 Hz and typically exhibit soft lags (soft
photons lag hard photons), whereas QPOs in the radio-bright plateau state are
found below 2.2 Hz and consistently show hard lags. The phase lag at the QPO
frequency is strongly anti-correlated with the QPO frequency, changing sign at
2.2 Hz. However, the phase lag at the frequency of the first harmonic is
positive and nearly independent of frequency at at ~0.172 rad, regardless of
the radio emission. The lag-energy dependence at the first harmonic is also
independent of radio flux. However, the lags at the QPO frequency are negative
at all energies during the radio-quiet state, but lags at the QPO frequency
during the plateau state are positive at all energies and show a
'reflection-type' evolution of the lag-energy spectra with respect to the
radio-quiet state. The lag-energy dependence is roughly logarithmic, but there
is some evidence for a break around 4-6 keV. Finally, the Fourier
frequency-dependent phase lag spectra are fairly flat during the plateau state,
but increase from negative to positive during the radio-quiet state. We discuss
the implications of our results in the light of some generic models.


title:
Reconstruction of broad features in the primordial spectrum and inflaton
  potential from Planck

abstract:
  With the recently published Cosmic Microwave Background data from Planck we
address the optimized binning of the primordial power spectrum. As an important
modification to the usual binning of the primordial spectrum, along with the
spectral amplitude of the bins, we allow the position of the bins also to vary.
This technique enables us to address the location of the possible broad
physical features in the primordial spectrum with relatively smaller number of
bins compared to the analysis performed earlier. This approach is in fact a
reconstruction method looking for broad features in the primordial spectrum and
avoiding fitting noise in the data. Performing Markov Chain Monte Carlo
analysis we present samples of the allowed primordial spectra with broad
features consistent with Planck data. To test how realistic it is to have
step-like features in primordial spectrum we revisit an inflationary model,
proposed by A. A. Starobinsky which can address the similar features obtained
from the binning of the spectrum. Using the publicly available code BINGO, we
numerically calculate the local $f_{\rm NL}$ for this model in equilateral and
arbitrary triangular configurations of wavevectors and show that the obtained
non-Gaussianity for this model is consistent with Planck results. In this paper
we have also considered different spectral tilts at different bins to identify
the cosmological scale that the spectral index needs to have a red tilt and it
is interesting to report that spectral index cannot be well constrained up to
$k \sim 0.01~ {\rm Mpc}^{-1}$.


title: The return to the hard state of GX 339-4 as seen by Suzaku

abstract:
  The microquasar GX 339-4 was observed by Suzaku five times, spaced by a few
days, during its transition back to the hard state at the end of its 2010-2011
outburst. The 2-10 keV source flux decreases by a factor ~10 between the
beginning and the end of the monitoring. Simultaneous radio and OIR
observations highlighted the re-ignition of the radio emission just before the
beginning of the campaign, the maximum radio emission being reached between the
two first Suzaku pointings, while the IR peaked a few weeks latter. A
fluorescent iron line is always significantly detected. Fits with a gaussian or
Laor profiles give statistically equivalent results. In the case of a Laor
profile, fits of the five data sets simultaneously agree with a disk
inclination angle of ~20 degrees. The disk inner radius is <10-30 R_g in the
first two observations but almost unconstrained in the last three. A soft X-ray
excess is also present in these two first observations. Fits with a multicolor
disk component give disk inner radii in agreement with those obtained with the
iron line fits. The use of a physically more realistic model, including a
blurred reflection component and a comptonization continuum, give some hints of
the increase of the disk inner radius but the significances are always weak.
Interestingly, the addition of warm absorption significantly improves the fit
of OBS1 while it is not needed in the other observations. The radio-jet
re-ignition occurring between OBS1 and OBS2, these absorption features may
indicate the natural evolution from a disk wind and a jet. The comparison with
a long 2008 Suzaku observation of GX 339-4 in a persistent faint hard state
where a narrow iron line clearly indicates a disk recession, is discussed.


title:
Measuring Triple-Helix Synergy in the Russian Innovation Systems at
  Regional, Provincial, and National Levels

abstract:
  We measure synergy for the Russian national, provincial, and regional
innovation systems as reduction of uncertainty using mutual information among
the three distributions of firm sizes, technological knowledge-bases of firms,
and geographical locations. Half a million data at firm level in 2011 were
obtained from the Orbis database of Bureau Van Dijk. The firm level data were
aggregated at the levels of eight Federal Districts, the regional level of 83
Federal Subjects, and the single level of the Russian Federation. Not
surprisingly, the knowledge base of the economy is concentrated in the Moscow
region (22.8%); St. Petersburg follows with 4.0%. Only 0.4% of the firms are
classified as high-tech, and 2.7% as medium-tech manufacturing (NACE, Rev. 2).
Except in Moscow itself, high-tech manufacturing does not add synergy to any
other unit at any of the various levels of geographical granularity; instead it
disturbs regional coordination even in the region surrounding Moscow ("Moscow
Region"). In the case of medium-tech manufacturing, there is also synergy in
St. Petersburg. Knowledge-intensive services (KIS; including laboratories)
contribute 12.8% to the economy in terms of establishments and contribute to
the synergy in all Federal Districts (except the North-Caucasian Federal
District), but only in 30 of the 83 Federal Subjects. The synergy in KIS is
concentrated in centers of administration. Unlike Western European countries,
the knowledge-intensive services (which are often state-affiliated) thus
provide backbone to an emerging knowledge-based economy at the level of Federal
Districts, but the economy is otherwise not knowledge-based (except for the
Moscow region).


title: Phase-space approach to polaron response: Kadanoff and FHIP re-examined

abstract:
  A method is presented to obtain the linear response coefficients of a system
coupled to a bath. The method is based on a systematic truncation of the
Liouville equation for the reduced distribution function. The first order
truncation results are expected to be accurate in the low temperature and weak
coupling regime. Explicit expressions for the conductivity of the Fr\"ohlich
polaron are obtained, and the discrepancy between the Kadanoff and the
Feynman-Hellwarth-Iddings-Platzmann mobility is elucidated.


title: Rheology of Dense Sheared Granular Liquids

abstract:
  The rheology of dense sheared granular liquids is investigated based on the
mode-coupling theory (MCT). This extended MCT includes correlations for the
density-current mode as well as the density-density correlation mode, and a
self-consistent coupling equation for the energy balance condition. The
extended MCT exhibits disappearance of the two-step relaxation of the
density-density correlation function, and also successfully reproduces the
density dependence of the shear viscosity for volume fractions between 0.50 and
0.60, if we shift the density. However, it predicts unphysical tendency for the
granular temperature. The cause of this drawback and the possibilities of its
amendment are discussed.


title:
Local moment dynamics and screening effects in doped charge-transfer
  insulators

abstract:
  By means of Dynamical Mean-Field Theory we investigate the spin response
function of a model for correlated materials with d- or f-electrons hybridized
with more delocalized ligand orbitals. We point out the existence of two
different processes responsible for the dynamical screening of local moments of
the correlated electrons. Studying the local spin susceptibility we identify
the contribution of the "direct" magnetic exchange and of an "indirect" one
mediated by the itinerant uncorrelated orbitals. In addition, we characterize
the nature of the dynamical screening processes in terms of different classes
of diagrams in the hybridization-expansion contributing to the density-matrix.
Our analysis suggests possible ways of estimating the relative importance of
these two classes of screening processes in realistic calculations for
correlated materials.


title:
Crosstalk and transitions between multiple spatial maps in an attractor
  neural network model of the hippocampus: Collective motion of the activity
  (II)

abstract:
  The dynamics of a neural model for hippocampal place cells storing spatial
maps is studied. In the absence of external input, depending on the number of
cells and on the values of control parameters (number of environments stored,
level of neural noise, average level of activity, connectivity of place cells),
a 'clump' of spatially-localized activity can diffuse, or remains pinned due to
crosstalk between the environments. In the single-environment case, the
macroscopic coefficient of diffusion of the clump and its effective mobility
are calculated analytically from first principles, and corroborated by
numerical simulations. In the multi-environment case the heights and the widths
of the pinning barriers are analytically characterized with the replica method;
diffusion within one map is then in competition with transitions between
different maps. Possible mechanisms enhancing mobility are proposed and tested.


title:
Constrained Supersymmetry after the Higgs Boson Discovery: A global
  analysis with Fittino

abstract:
  We present preliminary results from the latest global fit analysis of the
constrained minimal supersymmetric standard model (CMSSM) performed within the
Fittino framework. The fit includes low-energy and astrophysical observables as
well as collider constraints from the non-observation of new physics in
supersymmetric searches at the LHC. Furthermore, the Higgs boson mass and
signal rate measurements from both the LHC and Tevatron experiments are
included via the program HiggsSignals. Although the LHC exclusion limits and
the Higgs mass measurements put tight constraints on the viable parameter
space, we find an acceptable fit quality once the Higgs signal rates are
included.


abstract:
  Dipolar Bose-Einstein condensates in triple-well potentials are well-suited
model systems for periodic optical potentials with important contributions of
the non-local and anisotropic dipole-dipole interaction, which show a variety
of effects such as self-organisation and formation of patterns. We address here
a macroscopic sample of dipolar bosons in the mean-field limit. This work is
based on the Gross-Pitaevskii description of dipolar condensates in triple-well
potentials by Peter et al 2012 J. Phys. B: At. Mol. Opt. Phys. 45 225302. Our
analysis goes beyond the calculation of ground states presented there and
clarifies the role of excited and metastable states in such systems. In
particular, we find the formation of phases originating from the interplay of
several states with distinct stability properties. As some of the phases are
formed by metastable states special attention is paid to the characteristics of
phase transitions in real-time and the dynamical stabilisation of the
condensate.


title:
Quantum algorithm for universal implementation of projective measurement
  of energy

abstract:
  A projective measurement of energy (PME) on a quantum system is a quantum
measurement, determined by the Hamiltonian of the system. PME protocols exist
when the Hamiltonian is given in advance. Unknown Hamiltonians can be
identified by quantum tomography, but the time cost to achieve a given accuracy
increases exponentially with the size of the quantum system. In this letter, we
improve the time cost by adapting quantum phase estimation, an algorithm
designed for computational problems, to measurements on physical systems. We
present a PME protocol without quantum tomography for Hamiltonians whose
dimension and energy scale are given but otherwise unknown. Our protocol
implements a PME to arbitrary accuracy without any dimension dependence on its
time cost. We also show that another computational quantum algorithm may be
used for efficient estimation of the energy scale. These algorithms show that
computational quantum algorithms have applications beyond their original
context with suitable modifications.


title: On some formality criteria for DG-Lie algebras

abstract:
  We give some formality criteria for a differential graded Lie algebra to be
formal. For instance, we show that a DG-Lie algebra L is formal if and only if
the natural spectral sequence computing the Chevalley-Eilenberg cohomology
H(L,L) degenerates at second page.


title:
Hybrid Mutual Authentication Protocol for 802.16j against Rogue Station
  and DoS Attack

abstract:
  WiMAX is a promising technology that provides high data throughput with low
delays for various user types and modes of operation. These advantages make
WiMAX applicable both for infrastructure purposes and end-client usage. Since
WiMAX is presented as a network framework and a last-mile technology, it is
believed to be capable of handling a wide range of usage scenarios. For
example, while the end users have an opportunity to use WiMAX as the primary
connection medium for acquiring services such as on-demand video streaming,
VoIP connections and mobile bank transactions, the service providers may use it
for data relaying purposes among access points. To meet the technical
requirements of these various scenarios, majority of the WiMAX research has
been conducted on physical and MAC layers; however little has been invested in
a comprehensive and efficient security solution, which has resulted in a wide
range of security weaknesses and reactive solutions. Many security problems
remain to be addressed in different modes and for different user types even in
the final security standard of WiMAX, PKMv2. Mobile multi-hop relay (MMR) WiMAX
networks have attracted lots of interest in wireless communication industry
because of its scalable coverage, improved data rate and relatively low cost.
Even with the additional security functionalities security of MMR WiMAX network
is the main challenge because messages have to be transmitted through one or
more relay stations, which makes it more difficult to ensure the authenticity
of messages and entities involved in the transmission. In this thesis, we
present a hybrid security solution to overcome the security problem of rogue
station (BS/RS) attack and denial of service attack (DoS) in MMR WiMAX.


title:
Validity of the Effective Fisher matrix for parameter estimation
  analysis: Comparing to the analytic Fisher matrix

abstract:
  The effective Fisher matrix method recently introduced by Cho et al. is a
semi-analytic approach to the Fisher matrix, in which a local overlap surface
is fitted by using a quadratic fitting function. Mathematically, the effective
Fisher matrix should be consistent with the analytic one at the infinitesimal
fitting scale. In this work, using the frequency-domain waveform (TaylorF2), we
give brief comparison results between the effective and analytic Fisher
matrices for several non-spinning binaries consisting of binary neutron stars
with masses of (1.4, 1.4)M_sun, black hole-neutron star of (1.4, 10)M_sun, and
binary black holes of (5, 5) and (10, 10)M_sun for a fixed signal to noise
ratio (SNR=20) and show a good consistency between two methods. We also give a
comparison result for an aligned-spin black hole-neutron star binary with a
black hole spin of \chi=1, where we define new mass parameters (Mc, \eta^-1,
\chi^7/2) to find good fitting functions to the overlap surface. The effective
Fisher matrix can also be computed by using the time-domain waveforms which are
generally more accurate than frequency-domain waveform. We show comparison
results between the frequency-domain and time-domain waveforms (TaylorT4) for
both the non-spinning aligned-spin binaries.


title:
The X-ray Zurich Environmental Study (X-ZENS). I. Chandra and XMM-Newton
  observations of AGNs in galaxies in nearby groups

abstract:
  We describe X-ray observations with Chandra and XMM-Newton of 18 galaxy
groups (M_group ~ 1-6x10^13 Msolar, z~0.05) from the Zurich Environmental Study
(ZENS). We aim to establish the frequency and properties, unaffected by host
galaxy dilution and obscuration, of AGNs in central and satellite galaxy
members, also as a function of halo-centric distance. X-ray point-source
detections are reported for 22 of 177 observed galaxies, down to a limit of
f_(0.5-8 keV) ~ 5x10^-15 erg cm^-2 s^-1, corresponding to a limiting luminosity
of L_(0.5-8 keV)~3x10^40 erg s^-1. With the majority of the X-ray sources
attributed to AGNs of low-to-moderate levels (L/L_Edd>~10^-4), we discuss the
detection rate in the context of the occupation of AGNs to halos of this mass
scale and redshift, and compare the structural/morphological properties between
AGN-active and non-active galaxies of different rank and location within the
group halos. We see a slight tendency for AGN hosts to have either relatively
brighter/denser disks (or relatively fainter/diffuse bulges) than non-active
galaxies of similar mass. At galaxy mass scales <10^11 Msolar, central galaxies
appear to be a factor ~4 more likely to host AGNs than satellite galaxies of
similar mass. This effect, coupled with the tendency for AGNs to reside in
massive galaxies, explains the (weak) trend for AGNs to be preferentially found
in the inner regions of groups, with no detectable trend with halo-centric
distance in the frequency of AGNs within the satellite population. Finally, our
data support other analyses in finding that the rate of decline with redshift
of AGN activity in groups matches that of the global AGN population, indicating
that either AGNs occur preferentially in groups, or that the evolution rate is
independent of halo mass. These trends are of potential importance, and require
X-ray coverage of a larger sample to be solidly confirmed.


title:
Power identities for L\'evy risk models under taxation and capital
  injections

abstract:
  In this paper we study a spectrally negative L\'evy process which is
refracted at its running maximum and at the same time reflected from below at a
certain level. Such a process can for instance be used to model an insurance
surplus process subject to tax payments according to a loss-carry-forward
scheme together with the flow of minimal capital injections required to keep
the surplus process non-negative. We characterize the first passage time over
an arbitrary level and the cumulative amount of injected capital up to this
time by their joint Laplace transform, and show that it satisfies a simple
power relation to the case without refraction. It turns out that this identity
can also be extended to a certain type of refraction from below. The net
present value of tax collected before the cumulative injected capital exceeds a
certain amount is determined, and a numerical illustration is provided.


title: Anisotropic power-law k-inflation

abstract:
  It is known that power-law k-inflation can be realized for the Lagrangian
$P=Xg(Y)$, where $X=-(\partial \phi)^2/2$ is the kinetic energy of a scalar
field $\phi$ and $g$ is an arbitrary function in terms of $Y=Xe^{\lambda
\phi/M_{pl}}$ ($\lambda$ is a constant and $M_{pl}$ is the reduced Planck
mass). In the presence of a vector field coupled to the inflaton with an
exponential coupling $f(\phi) \propto e^{\mu \phi/M_{pl}}$, we show that the
models with the Lagrangian $P=Xg(Y)$ generally give rise to anisotropic
inflationary solutions with $\Sigma/H=constant$, where $\Sigma$ is an
anisotropic shear and $H$ is an isotropic expansion rate. Provided these
anisotropic solutions exist in the regime where the ratio $\Sigma/H$ is much
smaller than 1, they are stable attractors irrespective of the forms of $g(Y)$.
We apply our results to concrete models of k-inflation such as the generalized
dilatonic ghost condensate/the DBI model and we numerically show that the
solutions with different initial conditions converge to the anisotropic
power-law inflationary attractors. Even in the de Sitter limit ($\lambda \to
0$) such solutions can exist, but in this case the null energy condition is
generally violated. The latter property is consistent with the Wald's cosmic
conjecture stating that the anisotropic hair does not survive on the de Sitter
background in the presence of matter respecting the dominant/strong energy
conditions.


title: A risk model with an observer in a Markov environment

abstract:
  We consider a spectrally-negative Markov additive process as a model of a
risk process in random environment. Following recent interest in alternative
ruin concepts, we assume that ruin occurs when an independent Poissonian
observer sees the process negative, where the observation rate may depend on
the state of the environment. Using an approximation argument and spectral
theory we establish an explicit formula for the resulting survival
probabilities in this general setting.
  We also discuss an efficient evaluation of the involved quantities and
provide a numerical illustration.


title: Ion-size effects on cuprate High Temperature Superconductors

abstract:
  There are two general ways to compress the cuprates, by external pressure or
by internal pressure as induced by isovalent-ion substitution. Paradoxically,
they have the opposite effect on the superconducting transition temperature.
This thesis seeks to understand the salient difference between these two
pressures.
  We study three families of cuprates where the ion size can be systematically
altered; Bi$_2$(Sr$_{1.6-x}$A$_x$)Ln$_{0.4}$CuO$_{6+ \delta}$, ACuO$_2 $ and
LnBa$_{2-x} $Sr$_x $Cu$_3 $O$_{7-\delta} $ where Ln is a Lanthenide or Y and
A=\{Mg,Ca,Sr,Ba\}. We use a variety of techniques to explore our paradox, for
example; Raman spectroscopy to measure the antiferromagnetic exchange energy
and energy gaps, Density Functional Theory to calculate the density of states,
Muon Spin Relaxation to measure the superfluid density as well as a variety of
more conventional techniques to synthesize and characterise our samples.
  Our Raman studies show that an energy scale for spin fluctuations cannot
resolve the different effects of the two pressures. Similarly the density of
states, while an important property, does not clearly resolve the paradox. Our
superfluid density measurements show that the disorder resulting from
isovalent-ion substitution is secondary in importance for the superconducting
transition temperature.
  Instead, we find that the polarisability is a key property of the cuprates
with regard to superconductivity. This understanding resolves the paradox! It
implies that electron pairing results from either (i) a short-range interaction
where the polarisability screens repulsive longer-range interactions and/or
(ii) the relatively unexplored idea of the exchange of quantized, coherent
polarisation waves. More generally, we have also demonstrated the utility of
studying ion-size effects to further our collective understanding of the
cuprates.


title:
Trace element content and magnetic properties of commercial HOPG samples
  studied by ion beam microscopy and SQUID magnetometry

abstract:
  In this study, the impurity concentration and magnetic response of nine
highly oriented pyrolytic graphite (HOPG) samples with different grades and
from different providers were determined using ion beam microscopy and SQUID
magnetometry. Apart from sideface contaminations in the as-received state, bulk
contamination of the samples in most cases consists of disk-shaped micron-sized
particles made of Ti and V with an additional Fe contamination around the grain
perimeter. The saturation magnetization typically increases with Fe
concentration, however, there is no simple correlation between Fe content and
magnetic moment. The saturation magnetization of one, respectively six, out of
nine samples clearly exceeds the maximum contribution from pure Fe or Fe3C. For
most samples the temperature dependence of the remanence decreases linearly
with T - a dependence found previously for defect-induced magnetism (DIM) in
HOPG. We conclude that apart from magnetic impurities, additional contribution
to the ferromagnetic magnetization exists in pristine HOPG in agreement with
previous studies. A comparative study between the results of ion beam
microscopy and the commonly used EDX analysis shows clearly that EDX is not a
reliable method for quantitative trace elemental analysis in graphite,
clarifying weaknesses and discrepancies in the element concentrations given in
the recent literature.


title:
Chemical pressure effects on structural, dielectric and magnetic
  properties of solid solutions Mn3-xCoxTeO6

abstract:
  The effects of Co2+ doping on the structural, magnetic and dielectric
properties of the multiferroic frustrated antiferromagnet Mn3TeO6 have been
investigated. Ceramic samples of the solid solution series Mn3-xCoxTeO6 were
prepared by a solid-state reaction route. X-ray and neutron powder diffraction
and electron microscopy techniques were combined with calorimetric, dielectric
and magnetic measurements to investigate the dependence of the crystal
structure and physical properties on temperature and composition. It is shown
that the compounds with x up to 2.4 all adopt the trigonal corundum-related
structure of pure Mn3TeO6 (space group R-3) in the temperature range 5-295 K
and that the lattice parameters a and c and the unit-cell volume V decrease
linearly with increasing Co2+ concentration. The low- temperature magnetic
susceptibility and heat capacity data evidence the antiferromagnetic ordering
of all samples. The Neel temperature linearly increases with Co2+ concentration
x. Curie-Weiss fits of the high temperature susceptibility indicate that the
magnetic frustration decreases with x. The derived magnetic structure of
Mn3TeO6 can be described as an incommensurately modulated magnetic spin state
with k = [0, 0, kz] and an elliptical spin- spiral order of spins within the
chains of MnO6 octahedra. With increasing Co2+ concentration the propagation
vector kz changes from 0.453 (x = 0) to 0.516 (x = 2.4). The magnetic
anisotropy changes as well, leading to a reorientation of the spiral-basal
plane. A possible coexistence of long-range order of electrical dipoles and
magnetic moments in Mn3-xCoxTeO6 is discussed.


title: Pulsations of rapidly rotating stars with compositional discontinuities

abstract:
  Recent observations of rapidly rotating stars have revealed the presence of
regular patterns in their pulsation spectra. This has raised the question as to
their physical origin, and in particular, whether they can be explained by an
asymptotic frequency formula for low-degree acoustic modes, as recently
discovered through numerical calculations and theoretical considerations. In
this context, a key question is whether compositional/density gradients can
adversely affect such patterns to the point of hindering their identification.
To answer this question, we calculate frequency spectra using two-dimensional
ESTER stellar models. These models use a multi-domain spectral approach,
allowing us to easily insert a compositional discontinuity while retaining a
high numerical accuracy. We analyse the effects of such discontinuities on both
the frequencies and eigenfunctions of pulsation modes in the asymptotic regime.
We find that although there is more scatter around the asymptotic frequency
formula, the semi-large frequency separation can still be clearly identified in
a spectrum of low-degree acoustic modes.


title: The ABM parton distributions tuned to LHC data

abstract:
  We present a global fit of parton distributions at next-to-next-to-leading
order (NNLO) in QCD. The fit is based on the world data for deep-inelastic
scattering, fixed-target data for the Drell-Yan process and includes, for the
first time, data from the Large Hadron Collider (LHC) for the Drell-Yan process
and the hadro-production of top-quark pairs. The analysis applies the
fixed-flavor number scheme for n_f=3,4,5, uses the MS-bar scheme for the strong
coupling \alpha_s and the heavy-quark masses and keeps full account of the
correlations among all non-perturbative parameters. At NNLO this returns the
values of \alpha_s(M_Z) = 0.1132 +- 0.0011 and m_t(pole) = 171.2 +- 2.4 GeV for
the top-quark pole mass.The fit results are used to compute benchmark cross
sections for Higgs production at the LHC to NNLO accuracy. We compare our
results to those obtained by other groups and show that differences can be
linked to different theoretical descriptions of the underlying physical
processes.


title:
Enhanced superconductivity and evidence for novel pairing in
  single-layer FeSe on SrTiO3 thin film under large tensile strain

abstract:
  Single-layer FeSe films with extremely expanded in-plane lattice constant of
3.99A are fabricated by epitaxially growing FeSe/Nb:SrTiO3/KTaO3
heterostructures, and studied by in situ angle-resolved photoemission
spectroscopy. Two elliptical electron pockets at the Brillion zone corner are
resolved with negligible hybridization between them, indicating the symmetry of
the low energy electronic structure remains intact as a free-standing
single-layer FeSe, although it is on a substrate. The superconducting gap
closes at a record high temperature of 70K for the iron based superconductors.
Intriguingly, the superconducting gap distribution is anisotropic but nodeless
around the electron pockets, with minima at the crossings of the two pockets.
Our results put strong constraints on the current theories, and support the
coexistence of both even and odd parity spin-singlet pairing channels as
classified by the lattice symmetry.


title:
Small-maturity asymptotics for the at-the-money implied volatility slope
  in L\'evy models

abstract:
  We consider the at-the-money strike derivative of implied volatility as the
maturity tends to zero. Our main results quantify the behavior of the slope for
infinite activity exponential L\'evy models including a Brownian component. As
auxiliary results, we obtain asymptotic expansions of short maturity
at-the-money digital call options, using Mellin transform asymptotics. Finally,
we discuss when the at-the-money slope is consistent with the steepness of the
smile wings, as given by Lee's moment formula.


title:
Channel Hardening-Exploiting Message Passing (CHEMP) Receiver in
  Large-Scale MIMO Systems

abstract:
  In this paper, we propose a MIMO receiver algorithm that exploits {\em
channel hardening} that occurs in large MIMO channels. Channel hardening refers
to the phenomenon where the off-diagonal terms of the ${\bf H}^H{\bf H}$ matrix
become increasingly weaker compared to the diagonal terms as the size of the
channel gain matrix ${\bf H}$ increases. Specifically, we propose a message
passing detection (MPD) algorithm which works with the real-valued matched
filtered received vector (whose signal term becomes ${\bf H}^T{\bf H}{\bf x}$,
where ${\bf x}$ is the transmitted vector), and uses a Gaussian approximation
on the off-diagonal terms of the ${\bf H}^T{\bf H}$ matrix. We also propose a
simple estimation scheme which directly obtains an estimate of ${\bf H}^T{\bf
H}$ (instead of an estimate of ${\bf H}$), which is used as an effective
channel estimate in the MPD algorithm. We refer to this receiver as the {\em
channel hardening-exploiting message passing (CHEMP)} receiver. The proposed
CHEMP receiver achieves very good performance in large-scale MIMO systems
(e.g., in systems with 16 to 128 uplink users and 128 base station antennas).
For the considered large MIMO settings, the complexity of the proposed MPD
algorithm is almost the same as or less than that of the minimum mean square
error (MMSE) detection. This is because the MPD algorithm does not need a
matrix inversion. It also achieves a significantly better performance compared
to MMSE and other message passing detection algorithms using MMSE estimate of
${\bf H}$. We also present a convergence analysis of the proposed MPD
algorithm. Further, we design optimized irregular low density parity check
(LDPC) codes specific to the considered large MIMO channel and the CHEMP
receiver through EXIT chart matching. The LDPC codes thus obtained achieve
improved coded bit error rate performance compared to off-the-shelf irregular
LDPC codes.


title: On harmonic representation of means

abstract:
  We characterize continuous, symmetric and homogeneous means $M$ that can be
represented in the form \begin{equation*} \frac{1}{M(x,y)}=\int_0^1
\frac{dt}{N\left(\tfrac{x+y}{2}-t\tfrac{x-y}{2},\tfrac{x+y}{2}+t\tfrac{x-y}{2}\right)}.
\end{equation*} New inequalities for means are derived from such
representation.


title:
Enhanced low-energy magnetic excitations via suppression of the
  itinerancy in Fe0.98-zCuzTe0.5Se0.5

abstract:
  We have performed resistivity and inelastic neutron scattering measurements
on three samples of Fe0.98-zCuzTe0.5Se0.5 with z = 0, 0.02, and 0.1. It is
found that with increasing Cu doping the sample's resistivity deviates
progressively from that of a metal. However, in contrast to expectations that
replacing Fe with Cu would suppress the magnetic correlations, the low-energy
(no larger than 12 meV) magnetic scattering is enhanced in strength, with
greater spectral weight and longer dynamical spin-spin correlation lengths.
Such enhancements can be a consequence of either enlarged local moments or a
slowing down of the spin fluctuations. In either case, the localization of the
conduction states induced by the Cu doping should play a critical role. Our
results are not applicable to models that treat 3d transition metal dopants
simply as effective electron donors.


title:
Revisiting the crystal electric field of P2-NaxCoO2 for the intermediate
  spin state of Co3+

abstract:
  The magnetic moment per Co4+ of P2(gamma)-type NaxCoO2 in Curie-Weiss metal
regime is revisited and examined under a newly proposed modification of the
octahedral crystal electric field (CEF). The proposed model explains the origin
of the existence of the intermediate state S=1 for Co3+ through an exciton-like
elementary excitation of the narrow gap between the split eg and t2g groups.
The CoO2 layer is proposed to be constructed from the tilted edge-sharing
square-planar CoO2 chains with inter-chain coupling. The square-planar CEF of
CoO2 requires covalent bond formation between Co and the four in-plane
neighboring oxygens, while the oxygens sitting in the neighboring chains can be
viewed as apical oxygens of low effective charge for a CoO6 pseudo-octahedron.
The reason why angle-resolved photoemission spectroscopy (ARPES) failed to
observe the local-density approximation (LDA) predicted e'g hole pockets at
kz=0 and the reversed order of the t2g splittings between LDA and CEF
calculations can also be resolved using the proposed model.


title: A controlled local-global theorem for simplicial complexes

abstract:
  In this paper we prove that a simplicial map of finite-dimensional locally
finite simplicial complexes has contractible point inverses if and only if it
is an $\epsilon$-controlled homotopy equivalence for all $\epsilon>0$ if and
only if $f\times \mathrm{id}_\mathbb{R}$ is a bounded homotopy equivalence
measured in the open cone over the target. This confirms for such a space $X$
the slogan that arbitrarily fine control over $X$ corresponds to bounded
control over the open cone $O(X_+)$. For the proof a one parameter family of
cellulations $\{X_\epsilon^\prime\}_{0<\epsilon<\epsilon(X)}$ is constructed
which provides a retracting map for $X$ which can be used to compensate for
sufficiently small control.


title: Soliton dynamics for the generalized Choquard equation

abstract:
  We investigate the soliton dynamics for a class of nonlinear Schr\"odinger
equations with a non-local nonlinear term. In particular, we consider what we
call {\em generalized Choquard equation} where the nonlinear term is
$(|x|^{\theta-N} * |u|^p)|u|^{p-2}u$. This problem is particularly interesting
because the ground state solutions are not known to be unique or
non-degenerate.


title: Torsion functions on moduli spaces in view of the cluster algebra

abstract:
  We introduce non-acyclic $PGL_n(\mathbb{C})$-torsion of a 3-manifold with
toroidal boundary as an extension of J. Porti's $PGL_2(\mathbb{C})$-torsion,
and present an explicit formula of the $PGL_n(\mathbb{C})$-torsion of a mapping
torus for a surface with punctures, by using the higher Teichm\"{u}ler theory
due to V. Fock and A. Goncharov. Our formula gives a concrete rational function
which represents the torsion function and comes from a concrete cluster
transformation associated with the mapping class.


title: Dynamics of Potentials in Bianchi Type Scalar-Tensor Cosmology

abstract:
  The present study investigates the nature of the field potential via new
technique known as reconstruction method for the scalar field potentials. The
key point of this technique is the assumption that Hubble parameter is
dependent on the scalar field. We consider Bianchi type I universe in the
gravitational framework of scalar-tensor gravity and explore the general form
of the scalar field potential. In particular, this field potential is
investigated for the matter contents like barotropic fluid, the cosmological
constant and Chaplygin gas. It is concluded that for a given value of Hubble
parameter, one can reconstruct the scalar potentials which can generate the
cosmology motivated by these matter contents.


title: Inventions on reducing keyboard size: A TRIZ based analysis

abstract:
  A conventional computer keyboard consists of as many as 101 keys. The
keyboard has several sections, such as text entry section, navigation section,
and numeric keypad etc. and each having several keys on the keyboard.
  The size of the keyboard is a major inconvenience for portable computers, as
they cannot be carried easily. Thus there are certain circumstances which
compels to reduce the size of a keyboard.
  Reducing the size of a keyboard leads to several problems. A reduced size
keyboard may not contain all the keys available on a full size keyboard; a
reduced size keyboard may not be convenient to operate, a reduced size keyboard
may have a different key layout which is difficult to learn etc.
  This article illustrates 10 inventions on reducing the size of the keyboard.
Various inventions have attempted to solve the contradictions so that the user
achieves the benefits of both "reduced size" and "typing comfort".


title: Effects of inner electrons on atomic strong-field ionization dynamics

abstract:
  The influence of inner electrons on the ionization dynamics in strong laser
fields is investigated in a wavelength regime where the inner electron dynamics
is usually assumed to be negligible. The role of inner electrons is of
particular interest for the application of frozen-core approximations and
pseudopotentials in time-dependent density functional theory (TDDFT) and the
single-active-electron (SAE) approximation in strong-field laser physics.
Results of TDDFT and SAE calculations are compared with exact ones obtained by
the numerical ab initio solution of the three-electron time-dependent
Schr\"odinger equation for a lithium model atom. It is found that dynamical
anti-screening, i.e., a particular form of dynamical core polarization, may
substantially alter the ionization rate in the single-photon regime.
Requirements for the validity of the approximations in the single and
multiphoton ionization domain are identified.


title: Room temperature triplet state spectroscopy of organic semiconductors

abstract:
  Organic light emitting devices and solar cells are machines that create,
manipulate and destroy excited states in organic semiconductors. It is crucial
to characterize these excited states, or excitons, to optimize device
performance in applications like displays and solar energy harvesting. This is
complicated if the excited state is a triplet because the electronic transition
is dark with a vanishing oscillator strength. As a consequence, triplet state
spectroscopy must usually be performed at cryogenic temperatures to reduce
competition from non-radiative rates. Here, we control non-radiative rates by
engineering a solid-state host matrix containing the target molecule, allowing
the observation of phosphorescence at room temperature and alleviating
constraints of cryogenic experiments. We test these techniques on a wide range
of materials with functionalities spanning multi-exciton generation (singlet
exciton fission), organic light emitting device host materials, and thermally
activated delayed fluorescence type emitters. Control of non-radiative modes in
the matrix surrounding a target molecule may also have broader applications in
light emitting and photovoltaic devices.


title:
A cyclic time-dependent Markov process to model daily patterns in wind
  turbine power production

abstract:
  Wind energy is becoming a top contributor to the renewable energy mix, which
raises potential reliability issues for the grid due to the fluctuating nature
of its source. To achieve adequate reserve commitment and to promote market
participation, it is necessary to provide models that can capture daily
patterns in wind power production. This paper presents a cyclic inhomogeneous
Markov process, which is based on a three-dimensional state-space (wind power,
speed and direction). Each time-dependent transition probability is expressed
as a Bernstein polynomial. The model parameters are estimated by solving a
constrained optimization problem: The objective function combines two maximum
likelihood estimators, one to ensure that the Markov process long-term behavior
reproduces the data accurately and another to capture daily fluctuations. A
convex formulation for the overall optimization problem is presented and its
applicability demonstrated through the analysis of a case-study. The proposed
model is capable of reproducing the diurnal patterns of a three-year dataset
collected from a wind turbine located in a mountainous region in Portugal. In
addition, it is shown how to compute persistence statistics directly from the
Markov process transition matrices. Based on the case-study, the power
production persistence through the daily cycle is analysed and discussed.


title: The Mrk 231 molecular outflow as seen in OH

abstract:
  We report on the Herschel/PACS observations of OH in Mrk 231, with detections
in 9 doublets observed within the PACS range, and present radiative transfer
models for the outflowing OH. Signatures of outflowing gas are found in up to 6
OH doublets with different excitation requirements. At least two outflowing
components are identified, one with OH radiatively excited, and the other with
low excitation, presumably spatially extended. Particularly prominent, the blue
wing of the absorption detected in the in-ladder 2Pi_{3/2} J=9/2-7/2 OH doublet
at 65 um, with E_lower=290 K, indicates that the excited outflowing gas is
generated in a compact and warm (circum)nuclear region. Because the excited,
outflowing OH gas in Mrk 231 is associated with the warm, far-IR continuum
source, it is likely more compact (diameter of 200-300 pc) than that probed by
CO and HCN. Nevertheless, its mass-outflow rate per unit of solid angle as
inferred from OH is similar to that previously derived from CO,
>~70x(2.5x10^{-6}/X_{OH}) Msun yr^{-1} sr^{-1}, where X_{OH} is the OH
abundance relative to H nuclei. In spherical symmetry, this would correspond to
>~850x(2.5x10^{-6}/X_{OH}) Msun yr^{-1}, though significant collimation is
inferred from the line profiles. The momentum flux of the excited component
attains ~15 L_{AGN}/c, with an OH column density of (1.5-3)x10^{17} cm^-2 and a
mechanical luminosity of ~10^{11} Lsun. The detection of very excited OH
peaking at central velocities indicates the presence of a nuclear reservoir of
gas rich in OH, plausibly the 130-pc scale circumnuclear torus previously
detected in OH megamaser emission, that may be feeding the outflow. An
exceptional ^{18}OH enhancement, with OH/^{18}OH<~30 at both central and
blueshifted velocities, is likely the result of interstellar-medium processing
by recent starburst/SNe activity.


title:
Product formulas for a two-parameter family of Heckman-Opdam
  hypergeometric functions of type BC

abstract:
  In this paper we present explicit product formulas for a continuous
two-parameter family of Heckman-Opdam hypergeometric functions of type BC on
Weyl chambers $C_q\subset \mathbb R^q$ of type $B$. These formulas are related
to continuous one-parameter families of probability-preserving convolution
structures on $C_q\times\mathbb R$. These convolutions on $C_q\times\mathbb R$
are constructed via product formulas for the spherical functions of the
symmetric spaces $U(p,q)/ (U(p)\times SU(q))$ and associated double coset
convolutions on $C_q\times\mathbb T$ with the torus $\mathbb T$. We shall
obtain positive product formulas for a restricted parameter set only, while the
associated convolutions are always norm-decreasing. Our paper is related to
recent positive product formulas of R\"osler for three series of Heckman-Opdam
hypergeometric functions of type BC as well as to classical product formulas
for Jacobi functions of Koornwinder and Trimeche for rank $q=1$.


title: Structures in the cosmic ray energy spectra

abstract:
  All the components of cosmic rays have 'structure' in their energy spectra at
some level, ie deviations from a simple power law, and their examination is
relevant to the origin of the particles. Emphasis, here, is placed on the
large-scale structures in the spectra of nuclei (the 'knee' at about 3 PeV),
that of electrons and positrons (a shallow 'upturn' at about 100 GeV) and the
positron to electron plus positron ratio (an upturn starting at about 5 GeV).
  Fine structure is defined as deviations from the smooth spectra which already
allow for the large-scale structure. Search for the fine structure has been
performed in the precise data on positron to electron plus positron ratio
measured by the AMS-02 experiment. Although no fine structure is indicated, it
could in fact be present at the few percent level.


title: Optimal Order Scheduling for Deterministic Liquidity Patterns

abstract:
  We consider a broker who has to place a large order which consumes a sizable
part of average daily trading volume. The broker's aim is thus to minimize
execution costs he incurs from the adverse impact of his trades on market
prices. By contrast to the previous literature, see, e.g., Obizhaeva and Wang
(2005), Predoiu, Shaikhet, and Shreve (2011), we allow the liquidity parameters
of market depth and resilience to vary deterministically over the course of the
trading period. The resulting singular optimal control problem is shown to be
tractable by methods from convex analysis and, under minimal assumptions, we
construct an explicit solution to the scheduling problem in terms of some
concave envelope of the resilience adjusted market depth.


title:
Application of the Baade-Wesselink method to a pulsating cluster Herbig
  Ae star: H254 in IC348

abstract:
  In this paper we present new photometric and radial velocity data for the PMS
$\delta$ Sct star H254, member of the young cluster IC 348. Photometric
V,R$_C$,I$_C$ light curves were obtained at the Loiano and Asiago telescopes.
The radial velocity data was acquired by means of the SARG@TNG spectrograph.
High-resolution spectroscopy allowed us to derive precise stellar parameters
and the chemical composition of the star, obtaining: T$_{\rm
eff}$\,=\,6750\,$\pm$\,150 K; $\log g$\,=\,4.1\,$\pm$\,0.4 dex;
[Fe/H]=-0.07$\pm$0.12 dex. Photometric and spectroscopic data were used to
estimate the total absorption in the $V$ band A$_{\rm V}$=2.06$\pm$0.05 mag, in
agreement with previous estimates. We adopted the technique of the difference
in phase and amplitude between different photometric bands and radial
velocities to verify that H254 is (definitely) pulsating in a radial mode. This
occurrence allowed us to apply the CORS realization of the Baade--Wesselink
method to obtain a value for the linear radius of H254 equal to 3.3$\pm$0.7
$R_\odot$.
  This result was used in conjunction with photometry and effective temperature
to derive a distance estimate of 273$\pm$23 pc for H254, and, in turn for IC
348, the host cluster. This value is in agreement within the errors with the
results derived from several past determinations and the evaluation obtained
through the Hipparcos parallaxes. Finally, we derived the luminosity of H254
and studied its position in the Hertzsprung--Russell diagram. From this
analysis it results that this $\delta$--Scuti occupies a position close to the
red edge of the instability strip, pulsates in the fundamental mode, has a mass
of about 2.2 $M_\odot$ and an age of 5$\pm$1 Myr, older than previous
estimates.


title: Polyakov loop, Hadron Resonance Gas Model and Thermodynamics of QCD

abstract:
  We summarize recent results on the hadron resonance gas description of QCD.
In particular, we apply this approach to describe the equation of state and the
vacuum expectation value of the Polyakov loop in several representations.
Ambiguities related to exactly which states should be included are discussed.


title: Diffuse scattering in metallic tin polymorphs

abstract:
  The lattice dynamics of the metallic tin {\beta} and {\gamma} polymorphs has
been studied by a combination of diffuse scattering, inelastic x-ray scattering
and density functional perturbation theory. The non-symmorphic space group of
the {\beta}-tin structure results in unusual asymmetry of thermal diffuse
scattering. Strong resemblance of the diffuse scattering intensity distribution
in {\beta} and {\gamma}-tin were observed, reflecting the structural
relationship between the two phases and revealing the qualitative similarity of
the underlying electronic potential. The strong influence of the electron
subsystem on inter-ionic interactions creates anomalies in the phonon
dispersion relations. All observed features are described in great detail by
density functional perturbation theory for both {\beta}- and {\gamma}-tin at
arbitrary momentum transfers. The combined approach delivers thus a complete
picture of the lattice dynamics in harmonic description.


title: Dynamics on the cone: closed orbits and superintegrability

abstract:
  The generalization of Bertrand's theorem to the case of the motion of point
particle on the surface of a cone is presented. The superintegrability of such
models is discussed. The additional integrals of motion are analyzed for the
case of Kepler and harmonic oscillator potentials.


title:
Rapidity distributions in exclusive Z + jet and photon + jet events in
  pp collisions at sqrt(s) = 7 TeV

abstract:
  Rapidity distributions are presented for events containing either a Z boson
or a photon with a single jet in proton-proton collisions produced at the CERN
LHC. The data, collected with the CMS detector at sqrt(s) = 7 TeV, correspond
to an integrated luminosity of 5.0 inverse femtobarns. The individual rapidity
distributions of the boson and the jet are consistent within 5% with
expectations from perturbative QCD. However, QCD predictions for the sum and
the difference in rapidities of the two final-state objects show discrepancies
with CMS data. In particular, next-to-leading-order QCD calculations, and two
common Monte Carlo event generators using different methods to match
matrix-element partons with parton showers, appear inconsistent with the data
as well as with each other.


title: A note on the policy implications of the fiscal multiplier

abstract:
  We present an elementary analysis of the dynamical aspects of the GDP /
government surplus multiplier with relevance to the assessment of a country's
debt repayment policy. We show the (at first) counter intuitive result that in
order to reduce the Debt/GDP ratio, countries with high Debt to GDP should go
into further debt, as long as the Debt to GDP ratio is roughly greater than the
inverse of the multiplier. Thus small values of the multiplier make further
debt undesirable, and conversely.


title: On crystal ground state in the Schr\"odinger-Poisson model

abstract:
  A space-periodic ground state is shown to exist for lattices of smeared ions
in $\R^3$ coupled to the Schr\"odinger and scalar fields. The elementary cell
is necessarily neutral. The 1D, 2D and 3D lattices in $\R^3$ are considered,
and a ground state is constructed by minimizing the energy per cell. The case
of a 3D lattice is rather standard, because the elementary cell is compact, and
the spectrum of the Laplacian is discrete. In the cases of 1D and 2D lattices,
the energy functional is differentiable only on a dense set of variations, due
to the presence of the continuous spectrum of the Laplacian that causes the
infrared divergence of the Coulomb bond. Respectively, the construction of
electrostatic potential and the derivation of the Schr\"odinger equation for
the minimizer in these cases require an extra argument.
  The space-periodic ground states for 1D and 2D lattices give the model of the
nanostructures similar to the carbon nanotubes and graphene respectively.


title: Source-Channel Matching for Sources with Memory

abstract:
  In this paper we analyze the probabilistic matching of sources with memory to
channels with memory so that symbol-by-symbol code with memory without
anticipation are optimal, with respect to an average distortion and excess
distortion probability. We show achievability of such a symbolby- symbol code
with memory without anticipation, and we show matching for the Binary Symmetric
Markov source (BSMS(p)) over a first-order symmetric channel with a cost
constraint.


title: Discretized fractional substantial calculus

abstract:
  This paper discusses the properties and the numerical discretizations of the
fractional substantial integral $$I_s^\nu f(x)=\frac{1}{\Gamma(\nu)}
\int_{a}^x{\left(x-\tau\right)^{\nu-1}}e^{-\sigma(x-\tau)}{f(\tau)}d\tau,\nu>0,
$$ and the fractional substantial derivative $$D_s^\mu f(x)=D_s^m[I_s^\nu
f(x)], \nu=m-\mu,$$ where $D_s=\frac{\partial}{\partial x}+\sigma=D+\sigma$,
$\sigma$ can be a constant or a function without related to $x$, say
$\sigma(y)$; and $m$ is the smallest integer that exceeds $\mu$. The Fourier
transform method and fractional linear multistep method are used to analyze the
properties or derive the discretized schemes. And the convergences of the
presented discretized schemes with the global truncation error
$\mathcal{O}(h^p)$$ (p=1,2,3,4,5)$ are theoretically proved and numerically
verified.


title: Galactic Orbits of Hipparcos Stars: Classification of Stars

abstract:
  The Galactic orbits of 27 440 stars of all classes with accurate coordinates
and parallaxes of more than 3 mas from the Hipparcos catalogue, proper motions
from the Tycho-2 catalogue, and radial velocities from the Pulkovo Compilation
of Radial Velocities (PCRV) are analyzed. The sample obtained is much more
representative than the Geneva-Copenhagen survey and other studies of Galactic
orbits in the solar neighborhood. An estimation of the influence of systematic
errors in the velocities on orbital parameters shows that the errors of the
proper motions due to the duplicity of stars are tangible only in the
statistics of orbital parameters for very small samples, while the errors of
the radial velocities are noticeable in the statistics of orbital parameters
for halo stars. Therefore, previous studies of halo orbits may be erroneous.
The distribution of stars in selection-free regions of the multidimensional
space of orbital parameters, dereddened colors, and absolute magnitudes is
considered. Owing to the large number of stars and the high accuracy of PCRV
radial velocities, nonuniformities of this distribution (apart from the
well-known dynamical streams) have been found. Stars with their peri- and
apogalacticons in the disk, perigalacticons in the bulge and apogalacticons in
the disk, perigalacticons in the bulge and apogalacticons in the halo, and
perigalacticons in the disk and apogalacticons in the halo have been
identified. Thus, the bulge and the halo are inhomogeneous structures, each
consisting of at least two populations. The radius of the bulge has been
determined as 2 kpc.


title:
A Cryogenic Ultra-Low-Noise MMIC-based LNA with a discrete First Stage
  Transistor Suitable for Radio Astronomy Applications

abstract:
  In this paper a new design of MMIC based LNA is outlined. This design uses a
discrete 100-nm InP HEMT placed in front of an existing InP MMIC LNA to lower
the overall noise temperature of the LNA. This new approach known as the
Transistor in front of MMIC (T+MMIC) LNA, possesses a gain in excess of 40dB
and an average noise temperature of 9.4K compared to 14.5K for the equivalent
MMIC-only LNA measured across a 27-33GHz bandwidth at a physical temperature of
8K. A simple ADS model offering further insights into the operation of the LNA
is also presented and a potential radio astronomy application is discussed


title: Entanglement entropy in quasi-symmetric multi-qubit states

abstract:
  We generalize the symmetric multi-qubit states to their q-analogs, whose
basis vectors are identified with the q-Dicke states. We study the entanglement
entropy in these states and find that entanglement is extruded towards certain
regions of the system due to the inhomogeneity aroused by q-deformation. We
also calculate entanglement entropy in ground states of a related q-deformed
Lipkin-Meshkov-Glick model and show that the singularities of entanglement can
correctly signify the quantum phase transition points for different strengths
of q-deformation.


title:
Cosmic superstring networks with Y-junctions: Evolution, B-modes and
  Gravitational waves

abstract:
  We review the properties and evolution of strings networks containing both a
spectrum of string tensions as well as Y-junctions, namely a point at which
three different strings meet. Such a situation is expected in cosmic
superstring networks, where the tension of the different strings is determined
by the fundamental string tension $\mu_F$ as well as the string coupling $g_s$.
We discuss evolution of such a network, and the proliferation of kinks as they
travel through junctions. These effects can leave observational signals on
B-modes and gravitational waves, which can then in turn constrain the
underlying parameters of the theory.


title: A generalization of Levin-Schnorr's theorem

abstract:
  In this paper, we will generalize the definition of partially random or
complex reals, and then show the duality of random and complex, i.e., a
generalized version of Levin-Schnorr's theorem. We also study randomness from
the view point of arithmetic using the relativization to a complete
$\Pi^0_1$-class.


title: Storing High-Dimensional Quantum States in a Cold Atomic Ensemble

abstract:
  The reversible transfer of the quantum information between a photon, an
information carrier, and a quantum memory with high fidelity and reliability is
the prerequisite for realizing a long-distance quantum communication and a
quantum network. Encoding photons into higher-dimensional states could
significantly increase their information-carrying capability and network
capacity. Moreover, the large-alphabet quantum key distribution affords a more
secure flux of information. Quantum memories have been realized in different
physical systems, such as atomic ensembles and solid systems etc., but to date,
all quantum memories only realize the storage and retrieval of the photons
lived in a two-dimensional space spanned for example by orthogonal
polarizations, therefore only a quantum bit could be stored there. Here, we
report on the first experimental realization of a quantum memory storing a
photon lived in a three-dimensional space spanned by orbital angular momentums
via electromagnetically induced transparency in a cold atomic ensemble. We
reconstruct the storage process density matrix with the fidelity of 85.3% by
the aid of a 4-f imaging system experimentally. The ability to store a
high-dimensional quantum state with high fidelity is very promising for
building a high-dimensional quantum network.


title: Challenging the minimal supersymmetric SU(5) model

abstract:
  We review the main constraints on the parameter space of the minimal
renormalizable supersymmetric SU(5) grand unified theory. They consist of the
Higgs mass, proton decay, electroweak symmetry breaking and fermion masses.
Superpartner masses are constrained both from below and from above, giving hope
for confirming or definitely ruling out the theory in the future. This
contribution is based on Ref. [1].


title: Magnetocapillary Swimmers

abstract:
  We present an experiment where three mesoscopic soft ferromagnetic beads are
placed onto a liquid surface and submitted to the influence of magnetic fields.
A vertical magnetic field creates a repulsion which counterbalances the
capillary attraction. We show that the competition with a second, oscillating
field, deforms the structure in a non reciprocal way. As a consequence, the
structure is able to swim. This experiment is fully described in a fluid
dynamics video attached to this submission.


title: Bogoliubov theory for atom scattering into separate regions

abstract:
  We review the Bogoliubov theory in the context of recent experiments, where
atoms are scattered from a Bose-Einstein Condensate into two well-separated
regions. We find the full dynamics of the pair-production process, calculate
the first and second order correlation functions and show that the system is
ideally number-squeezed. We calculate the Fisher information to show how the
entanglement between the atoms from the two regions changes in time. We also
provide a simple expression for the lower bound of the useful entanglement in
the system in terms of the average number of scattered atoms and the number of
modes they occupy. We then apply our theory to a recent "twin-beam" experiment
[R. B\"ucker {\it et al.}, Nat. Phys. {\bf 7}, 608 (2011)]. The only numerical
step of our semi-analytical description can be easily solved and does not
require implementation of any stochastic methods.


title:
New foundations and unification of basic plasma physics by means of
  classical mechanics

abstract:
  The derivation of Debye shielding and Landau damping from the $N$-body
description of plasmas requires many pages of heavy kinetic calculations in
classical textbooks and is done in distinct, unrelated chapters. Using Newton's
second law for the $N$-body system, we perform this derivation in a few steps
with elementary calculations using standard tools of calculus, and no
probabilistic setting. Unexpectedly, Debye shielding is encountered on the way
to Landau damping. The theory is extended to accommodate a correct description
of trapping or chaos due to Langmuir waves, and to avoid the small amplitude
assumption for the electrostatic potential. Using the shielded potential,
collisional transport is computed for the first time by a convergent expression
including the correct calculation of deflections for all impact parameters.
Shielding and collisional transport are found to be two related aspects of the
repulsive deflections of electrons.


title: A code space for a generalized IFS

abstract:
  We study the concept of a code (or shift) space for a generalized iterated
function system (GIFS in short). We prove that relations between GIFSs and
their code spaces are analogous to the case of classical IFSs. As an
application, we consider the problem of connectedness of attractors of GIFSs.
Many of our results are strengthenings of the ones proved recently by Mihail,
Miculescu and Secelean, but some are completely new.


title: Variational principle for weighted porous media equation

abstract:
  In this paper we state the variational principle for the weighted porous
media equation. It extends V.I. Arnold's approach to the description of Euler
flows as a geodesics on some manifold, i.e. as a critical points of some energy
functional.


title:
A Bayesian Network View on Acoustic Model-Based Techniques for Robust
  Speech Recognition

abstract:
  This article provides a unifying Bayesian network view on various approaches
for acoustic model adaptation, missing feature, and uncertainty decoding that
are well-known in the literature of robust automatic speech recognition. The
representatives of these classes can often be deduced from a Bayesian network
that extends the conventional hidden Markov models used in speech recognition.
These extensions, in turn, can in many cases be motivated from an underlying
observation model that relates clean and distorted feature vectors. By
converting the observation models into a Bayesian network representation, we
formulate the corresponding compensation rules leading to a unified view on
known derivations as well as to new formulations for certain approaches. The
generic Bayesian perspective provided in this contribution thus highlights
structural differences and similarities between the analyzed approaches.


title: Rasmussen's spectral sequences and the sl(N)-concordance invariants

abstract:
  Combining known spectral sequences with a new spectral sequence relating
reduced and unreduced sl(N)-homology yields a relationship between the
Homflypt-homology of a knot and its sl(N)-concordance invariants. As an
application, some of the sl(N)-concordance invariants are shown to be linearly
independent.


title: Deep Multiple Kernel Learning

abstract:
  Deep learning methods have predominantly been applied to large artificial
neural networks. Despite their state-of-the-art performance, these large
networks typically do not generalize well to datasets with limited sample
sizes. In this paper, we take a different approach by learning multiple layers
of kernels. We combine kernels at each layer and then optimize over an estimate
of the support vector machine leave-one-out error rather than the dual
objective function. Our experiments on a variety of datasets show that each
layer successively increases performance with only a few base kernels.


title:
Elastic measurements on macroscopic three-dimensional pentamode
  metamaterials

abstract:
  Pentamode metamaterials approximate tailorable artificial liquids. Recently,
microscopic versions of these intricate three-dimensional structures have been
fabricated, but direct experimental characterization has not been possible yet.
Here, using three-dimensional printing, we fabricate macroscopic polymer-based
samples with many different combinations of the small connection diameter $d$
and the lattice constant $a$. Direct measurements of the static shear modulus
and the Young's modulus reveal that both scale approximately according to
$(d/a)^3$, in good agreement with continuum-mechanics calculations. For the
smallest accessible values of $d/a \approx 1.5\%$, we find derived ratios of
bulk modulus $B$ to shear modulus $G$ of $B/G \approx 1000$.


title: Electron shakeoff following the ?+ decay of trapped 35Ar+ ions

abstract:
  The electron shakeoff of $^{35}$Cl atoms resulting from the $\beta$$^+$ decay
of $^{35}$Ar$^+$ ions has been investigated using a Paul trap coupled to a
recoil-ion spectrometer. The charge-state distribution of the recoiling
daughter nuclei is compared to theoretical calculations accounting for shakeoff
and Auger processes. The calculations are in excellent agreement with the
experimental results and enable to identify the ionization reaction routes
leading to the formation of all charge states.


title: Low frequency signals of large scale GW-interferometers

abstract:
  Application of the large scale gravitational wave interferometers for
measurement of geophysical signals at very low frequencies is considered.
Analysis is concentrated on the mechanism of penetration of quasistatic
geophysical perturbation through the main interferometer output. It is shown
that it has a parametrical nature resulted in slow variations of the optical
transfer function of the interferometer. Geophysical modulation index is
calculated for any harmonical component of the output spectrum, but mainly for
a photon circulation frequency appeared in the case of stochastic illumination
of modes neighbour to the central resonance. Value of the effect is estimated
for different operational regimes of the device. For improvement of geophysical
signal readout a modernization of the instrument with using of two component
resonance optical pump is proposed and a correspondent calculation is carried
out. Numerical estimations for different regimes of the setup are given
together with discussion of possible application for measuring some weak
gravitational effects.


title:
Fluid dynamics with saturated minijet initial conditions in
  ultrarelativistic heavy-ion collisions

abstract:
  Using next-to-leading order perturbative QCD and a conjecture of saturation
to suppress the production of low-energy partons, we calculate the initial
energy densities and formation times for the dissipative fluid dynamical
evolution of the quark-gluon plasma produced in ultrarelativistic heavy-ion
collisions. We identify the framework uncertainties and demonstrate the
predictive power of the approach by a good global agreement with the measured
centrality dependence of charged particle multiplicities, transverse momentum
spectra and elliptic flow simultaneously for the Pb+Pb collisions at the LHC
and Au+Au at RHIC. In particular, the shear viscosity in the different phases
of QCD matter is constrained in this new framework simultaneously by all these
data.


title: The electronic structure of the silicon vacancy color center in diamond

abstract:
  The negatively charged silicon vacancy (SiV) color center in diamond has
recently proven its suitability for bright and stable single photon emission.
However, its electronic structure so far has remained elusive. We here explore
the electronic structure by exposing single SiV defects to a magnetic field
where the Zeeman effect lifts the degeneracy of magnetic sublevels. The similar
response of single centers and a SiV ensemble in a low strain reference sample
proves our ability to fabricate almost perfect single SiVs, revealing the true
nature of the defect's electronic properties. We model the electronic states
using a group-theoretical approach yielding a good agreement with the
experimental observations. Furthermore, the model correctly predicts
polarization measurements on single SiV centers and explains recently
discovered spin selective excitation of SiV defects.


title:
SwiftCloud: Fault-Tolerant Geo-Replication Integrated all the Way to the
  Client Machine

abstract:
  Client-side logic and storage are increasingly used in web and mobile
applications to improve response time and availability. Current approaches tend
to be ad-hoc and poorly integrated with the server-side logic. We present a
principled approach to integrate client- and server-side storage. We support
mergeable and strongly consistent transactions that target either client or
server replicas and provide access to causally-consistent snapshots
efficiently. In the presence of infrastructure faults, a client-assisted
failover solution allows client execution to resume immediately and seamlessly
access consistent snapshots without waiting. We implement this approach in
SwiftCloud, the first transactional system to bring geo-replication all the way
to the client machine. Example applications show that our programming model is
useful across a range of application areas. Our experimental evaluation shows
that SwiftCloud provides better fault tolerance and at the same time can
improve both latency and throughput by up to an order of magnitude, compared to
classical geo-replication techniques.


title: Pulsar timing noise from superfluid turbulence

abstract:
  Shear-driven turbulence in the superfluid interior of a neutron star exerts a
fluctuating torque on the rigid crust, causing the rotational phase to walk
randomly. The phase fluctuation spectrum is calculated analytically for
incompressible Kolmogorov turbulence and is found to be red; the half-power
point is set by the observed spin-down rate, the crust-superfluid lag, and the
dynamical response time of the superfluid. Preliminary limits are placed on the
latter quantities using selected time- and frequency-domain data. It is found
that measurements of the normalization and slope of the power spectrum are
reproduced for reasonable choices of the turbulence parameters. The results
point preferentially to the neutron star interior containing a turbulent
superfluid rather than a turbulent Navier-Stokes fluid. The implications for
gravitational wave detection by pulsar timing arrays are discussed briefly.


title: Second harmonic generation in dissipative metamaterials

abstract:
  Second harmonic generation is considered in lossy negative-index
metamaterials. It is shown that energy transfer from fundamental to harmonic
takes place in the entire sample for the range of phase mismatch values. Note
that in conventional case this range collapses to the point (ideal phase
matching). The dependance of the boundary of this range as function of
dissipation values is obtained using computer simulations.


title:
The Classification of Regular Surfaces Isogenous to a Product of Curves
  with $\chi(\mathcal O_S) = 2$

abstract:
  A complex surface $S$ is said to be isogenous to a product if $S$ is a
quotient $S=(C_1 \times C_2)/G$ where the $C_i$'s are curves of genus at least
two, and $G$ is a finite group acting freely on $C_1 \times C_2$. In this paper
we classify all regular surfaces isogenous to a product with $\chi(\mathcal
O_S) = 2$ under the assumption that the action of $G$ is unmixed i.e. no
element of $G$ exchange the factors of the product $C_1 \times C_2$.


title: Keyboard for inputting Chinese language

abstract:
  As the structure of Chinese characters are very different, it is very
difficult to input Chinese characters into computer quickly and conveniently.
The conventional keyboard does not support the pictorial characters in Chinese
language. There are 3000 to 6000 commonly used pictorial Chinese characters
(Hanzi).
  There are a few existing systems which include "PinYin" (phonetic) system, a
combination of the PinYin system and character form techniques, whole character
encoding, stroke input encoding, and stoke form encoding. Each of the methods
have their own advantages and disadvantages. This article describes two
inventions on inputting Chinese language through a standard keyboard.


title:
A Refinement of the Local Serrin--Type Regularity A refinement of the
  local Serrin--type regularity criterion for a suitable weak solution to the
  Navier--Stokes equations

abstract:
  We formulate a new criterion for regularity of a suitable weak solution v to
the Navier-Stokes equations at the space-time point (x_0,t_0). The criterion
imposes a Serrin-type integrability condition on v only in a backward
neighbourhood of (x_0,t_0), intersected with the exterior of a certain
space-time paraboloid with vertex at point (x_0,t_0). We make no special
assumptions on the solution in the interior of the paraboloid.


title: Superreplication when trading at market indifference prices

abstract:
  We study superreplication of European contingent claims in discrete time in a
large trader model with market indifference prices recently proposed by Bank
and Kramkov. We introduce a suitable notion of efficient friction in this
framework, adopting a terminology introduced by Kabanov, Rasonyi, and Stricker
in the context of models with proportional transaction costs. In our framework,
efficient friction ensures that large positions of the investor may lead to
large losses, a fact from which we derive the existence of superreplicating
strategies. We illustrate that without this condition there may be no
superreplicating strategy with minimal costs. In our main result, we establish
efficient friction under a tail condition on the conditional distributions of
the traded securities and under an asymptotic criterion on risk aversions of
the market makers. Another result asserts that strict monotonicity of the
conditional essential infima and suprema of the security prices is sufficient
for efficient friction. We give examples that satisfy the assumptions in our
conditions, which include non-degenerate finite sample space models as well as
Levy processes and an affine stochastic volatility model of
Barndorff-Nielsen-Shepard type.


title:
Approximation of passage times of gamma-reflected processes with fBm
  input

abstract:
  Define a gamma-reflected process
W_\gamma(t)=Y_H(t)-\gamma\inf_{s\in[0,t]}Y_H(s), t\ge0 with input process
{Y_H(t), t\ge 0} which is a fractional Brownian motion with Hurst index H\in
(0,1) and a negative linear trend. In risk theory {u-W_\gamma(t), t\ge 0} is
referred to as the risk process with tax payments of a loss-carry-forward type.
For various risk processes numerous results are known for the approximation of
the first and last passage times to 0 (ruin times) when the initial reserve $u$
goes to infinity. In this paper we show that for the gamma-reflected process
the conditional (standardized) first and last passage times are jointly
asymptotically Gaussian and completely dependent. An important contribution of
this paper is that it links ruin problems with extremes of non-homogeneous
Gaussian random fields defined by Y_H which are also investigated in this
contribution.


title: Keyboards for inputting Japanese language -A study based on US patents

abstract:
  The most commonly used Japanese alphabets are Kanji, Hiragana and Katakana.
The Kanji alphabet includes pictographs or ideographic characters that were
adopted from the Chinese alphabet. Hiragana is used to spell words of Japanese
origin, while Katakana is used to spell words of western or other foreign
origin.
  Two methods are commonly used to input Japanese to the computer. One, the
'kana input method' that uses a keyboard having 46 Japanese iroha (or kana)
letter keys. The other method is 'Roma-ji input method', where the Japanese
letters are composed of English input from a standard QWERTY keyboard. Both the
methods have their advantages and disadvantages.
  This article analyses two inventions on inputting Japanese language through a
computer keyboard. One invention uses a standard English keyboard to input
Japanese characters, the other invention uses a standard mobile phone key board
to input the Japanese characters.


title: A Wigner distribution function for finite oscillator systems

abstract:
  We define a Wigner distribution function for a one-dimensional finite quantum
system, in which the position and momentum operators have a finite
(multiplicity-free) spectrum. The distribution function is thus defined on
discrete phase-space, i.e. on a finite discrete square grid. These discrete
Wigner functions possess a number of properties similar to the Wigner function
for a continuous quantum system such as the quantum harmonic oscillator. As an
example, we consider the so-called su(2) oscillator model in dimension 2j+1,
which is known to tend to the canonical oscillator when j tends to infinity. In
particular, we compare plots of our discrete Wigner functions for the su(2)
oscillator with the well known plots of Wigner functions for the canonical
quantum oscillator. This comparison supports our approach to discrete Wigner
functions.


title: Coherence properties of cycling chaos

abstract:
  Cycling chaos is a heteroclinic connection between several chaotic
attractors, at which switching between the chaotic sets occur at growing time
intervals. Here we characterize the coherence properties of these switchings,
considering nearly periodic regimes that appear close to the cycling chaos due
to imperfections or to instability. Using numerical simulations of coupled
Lorenz, Roessler, and logistic map models, we show that the coherence is high
in the case of imperfection (so that asymptotically the cycling chaos is very
regular), while it is low close to instability of the cycling chaos.


title: Analytical theory of modulated magnetic solitons

abstract:
  Droplet solitons are coherently precessing solitary waves that have been
recently realized in thin ferromagnets with perpendicular anisotropy.In the
strongly nonlinear regime, droplets can be well approximated by a slowly
precessing, circular domain wall with a hyperbolic tangent form. Utilizing this
representation, this work develops a general droplet modulation theory and
applies it to study the long range effects of the magnetostatic field and a
nanocontact spin torque oscillator (NC-STO) where spin polarized currents act
as a gain source to counteract magnetic damping. An analysis of the dynamical
equations for the droplet's center, frequency and phase demonstrates a negative
processional frequency shift due to long range dipolar interactions, dependent
on film thickness. Further analysis also demonstrates the onset of a
saddle-node bifurcation at the minimum sustaining current for the NC-STO. The
basin of attraction associated with the stable node demonstrates that spin
torque enacts a restoring force to excursions of the droplet from the
nanocontact center, observed previously in numerical simulations. Large
excursions lead to the droplet's eventual decay into spin waves.


title: Solvency Markov Decision Processes with Interest

abstract:
  Solvency games, introduced by Berger et al., provide an abstract framework
for modelling decisions of a risk-averse investor, whose goal is to avoid ever
going broke. We study a new variant of this model, where, in addition to
stochastic environment and fixed increments and decrements to the investor's
wealth, we introduce interest, which is earned or paid on the current level of
savings or debt, respectively.
  We study problems related to the minimum initial wealth sufficient to avoid
bankruptcy (i.e. steady decrease of the wealth) with probability at least p. We
present an exponential time algorithm which approximates this minimum initial
wealth, and show that a polynomial time approximation is not possible unless P
= NP. For the qualitative case, i.e. p=1, we show that the problem whether a
given number is larger than or equal to the minimum initial wealth belongs to
both NP and coNP, and show that a polynomial time algorithm would yield a
polynomial time algorithm for mean-payoff games, existence of which is a
longstanding open problem. We also identify some classes of solvency MDPs for
which this problem is in P. In all above cases the algorithms also give
corresponding bankruptcy avoiding strategies.


title:
Sensitivity of intracavity filtering schemes for detecting gravitational
  waves

abstract:
  We consider enhancing the sensitivity of future gravitational-wave detectors
by adding optical filters inside the signal-recycling cavity -- an intracavity
filtering scheme, which coherently feeds the sideband signal back to the
interferometer with a proper frequency-dependent phase. We study three cases of
such a scheme with different motivations: (i) the case of backaction noise
evasion, trying to cancel radiation-pressure noise with only one filter cavity
for a signal-recycled interferometer; (ii) the speed-meter case, similar to the
speed-meter scheme proposed by Purdue and Chen [Phys. Rev. D 66, 122004 (2002)]
but without the resonant-sideband-extraction mirror, and also relieves the
optical requirement on the sloshing mirror; (iii) the broadband detection case
with squeezed-light input, numerically optimized for a broadband sensitivity.


title:
Oblique S and T Constraints on Electroweak Strongly-Coupled Models with
  a Light Higgs

abstract:
  Using a general effective Lagrangian implementing the chiral symmetry
breaking SU(2)L x SU(2)R -> SU(2){L+R}, we present a one-loop calculation of
the oblique S and T parameters within electroweak strongly-coupled models with
a light scalar. Imposing a proper ultraviolet behaviour, we determine S and T
at next-to-leading order in terms of a few resonance parameters. The
constraints from the global fit to electroweak precision data force the massive
vector and axial-vector states to be heavy, with masses above the TeV scale,
and suggest that the W+W- and ZZ couplings of the Higgs-like scalar should be
close to the Standard Model value. Our findings are generic, since they only
rely on soft requirements on the short-distance properties of the underlying
strongly-coupled theory, which are widely satisfied in more specific scenarios.


title:
Supersymmetric gauge theories, Coulomb gases and Chern-Simons matrix
  models

abstract:
  We develop Coulomb gas pictures of strong and weak coupling regimes of
supersymmetric Yang-Mills theory in five and four dimensions. By relating them
to the matrix models that arise in Chern-Simons theory, we compute their free
energies in the large N limit and establish relationships between the
respective gauge theories. We use these correspondences to rederive the N^3
behaviour of the perturbative free energy of supersymmetric gauge theory on
certain toric Sasaki-Einstein five-manifolds, and the one-loop thermal free
energy of N=4 supersymmetric Yang-Mills theory on a spatial three-sphere.

categories: hep-th cond-mat.stat-mech cond-mat.str-el math-ph math.MP


title: Homogeneous links and closed homogeneous braids

abstract:
  Is any positive knot the closure of a positive braid? No. But if we consider
positivity in terms of the generators of the braid group due to Birman, Ko and
Lee, then the answer is yes. In this paper we prove that the same occurs when
considering homogeneity.
  In the way we prove that the plumbing of two surfaces is a BKL-homogeneous
surface if and only if both summands are BKL-homogeneous surfaces, a parallel
result to that of Rudolph involving quasipositive surfaces. BKL-homogeneous
surfaces are, in fact, a natural generalization of quasipositive surfaces.


title: Timescape realized

abstract:
  We discuss a concrete proposal to realize the observer dependence of
expansion redshift employing a map that relates static to conformally static
geometries. This provides a manifest realization of Wiltshire's proposal for
observer selection which serves as a model to explain accelerated expansion


title:
Wetting heterogeneity in mixed-wet porous media controls flow
  dissipation

abstract:
  Pressure controlled displacement of an oil/water interface is studied in
dense packings of functionalized glass beads with well-defined spatial
wettability correlations. An enhanced dissipation is observed if the typical
extension $\xi$ of the same-type wetting domains is smaller than the average
bead diameter $d$. Three dimensional imaging using X-ray microtomography shows
that the frequency $n(s)$ of residual droplet volumes $s$ for different $\xi$
collapse onto the same curve. This indicates that the additional dissipation
for small $\xi$ is due to contact line pinning rather than an increase of
capillary break-up/coalescence events.


title: Direct derivation of "mirror" ABJ partition function

abstract:
  We study the partition function of the three-dimensional N=6 U(N)_k x
U(N+M)_{-k} superconformal Chern-Simons matter theory known as the ABJ theory.
We prove that the ABJ partition function on S^3 is exactly the same as a
formula recently proposed by Awata, Hirano and Shigemori. While this formula
was previously obtained by an analytic continuation from the L(2,1) lens space
matrix model, we directly derive this by using a generalization of the Cauchy
determinant identity. We also give an interpretation for the formula from brane
picture.


title: Webs and Posets

abstract:
  The non-Abelian exponentiation theorem has recently been generalised to
correlators of multiple Wilson line operators. The perturbative expansions of
these correlators exponentiate in terms of sets of diagrams called webs, which
together give rise to colour factors corresponding to connected graphs. The
colour and kinematic degrees of freedom of individual diagrams in a web are
entangled by mixing matrices of purely combinatorial origin. In this paper we
relate the combinatorial study of these matrices to properties of partially
ordered sets (posets), and hence obtain explicit solutions for certain families
of web-mixing matrix, at arbitrary order in perturbation theory. We also
provide a general expression for the rank of a general class of mixing
matrices, which governs the number of independent colour factors arising from
such webs. Finally, we use the poset language to examine a previously
conjectured sum rule for the columns of web-mixing matrices which governs the
cancellation of the leading subdivergences between diagrams in the web. Our
results, when combined with parallel developments in the evaluation of
kinematic integrals, offer new insights into the all-order structure of
infrared singularities in non-Abelian gauge theories.


title: Endemic infections are always possible on regular networks

abstract:
  We study the dependence of the largest component in regular networks on the
clustering coefficient, showing that its size changes smoothly without
undergoing a phase transition. We explain this behaviour via an analytical
approach based on the network structure, and provide an exact equation
describing the numerical results. Our work indicates that intrinsic structural
properties always allow the spread of epidemics on regular networks.


title: Bursting of rigid bubbles

abstract:
  We propose here a fluid dynamics video relating the bursting of soap rigid
films.


title:
Exact and asymptotic features of the edge density profile for the one
  component plasma in two dimensions

abstract:
  There is a well known analogy between the Laughlin trial wave function for
the fractional quantum Hall effect, and the Boltzmann factor for the
two-dimensional one-component plasma. The latter requires analytic continuation
beyond the finite geometry used in its derivation. We consider both disk and
cylinder geometry, and focus attention on the exact and asymptotic features of
the edge density. At the special coupling \Gamma := q^2/k_BT=2 the system is
exactly solvable. In particular the k-point correlation can be written as a k
\times k determinant, allowing the edge density to be computed to first order
in \Gamma - 2. A double layer structure is found, which in turn implies an
overshoot of the density as the edge of the leading support is approached from
inside the plasma. Asymptotic analysis shows that the deviation from the
leading order (step function) value is different for into the plasma than for
outside. For general \Gamma, a Gaussian fluctuation formula is used to study
the large deviation form of the density for N large but finite. This asymptotic
form involves thermodynamic quantities which we independently study, and
moreover an appropriate scaling gives the asymptotic decay of the limiting edge
density outside of the plasma.


title:
Electronic structure of the negatively-charged silicon-vacancy center in
  diamond

abstract:
  The negatively-charged silicon-vacancy (SiV$^-$) center in diamond is a
promising single photon source for quantum communications and information
processing. However, the center's implementation in such quantum technologies
is hindered by contention surrounding its fundamental properties. Here we
present optical polarization measurements of single centers in bulk diamond
that resolve this state of contention and establish that the center has a
$\langle111\rangle$ aligned split-vacancy structure with $D_{3d}$ symmetry.
Furthermore, we identify an additional electronic level and evidence for the
presence of dynamic Jahn-Teller effects in the center's 738 nm optical
resonance.


title:
Next-to-leading order in the large $N$ expansion of the multi-orientable
  random tensor model

abstract:
  In this paper we analyze in detail the next-to-leading order (NLO) of the
recently obtained large $N$ expansion for the multi-orientable (MO) tensor
model. From a combinatorial point of view, we find the class of Feynman tensor
graphs contributing to this order in the expansion. Each such NLO graph is
characterized by the property that it contains a certain non-orientable ribbon
subgraph (a non-orientable jacket). Furthermore, we find the radius of
convergence and the susceptibility exponent of the NLO series for this model.
These results represent a first step towards the larger goal of defining an
appropriate double-scaling limit for the MO tensor model.