title: Condensate flow in holographic models in the presence of dark matter

abstract:
  Holographic model of a three-dimensional current carrying superconductor or
superfluid with {\it dark matter} sector described by the additional
$U(1)$-gauge field coupled to the ordinary Maxwell one, has been studied in the
probe limit. We investigated analytically by the Sturm-Liouville variational
method, the holographic s-wave and p-wave models in the background of the AdS
soliton as well as five-dimensional AdS black hole spacetimes. The two models
of p-wave superfluids were considered, the so called $SU(2)$ and the
Maxwell-vector. Special attention has been paid to the dependence of the
critical chemical potential and critical transition temperature on the velocity
of the condensate and {\it dark matter} parameters. The current $J$ in
holographic three-dimensional superconductor studied here, shows the linear
dependence on $T_c-T$ for both s and p-wave symmetry. This is in a significant
contrast with the previously obtained results for two-dimensional
superconductors, which reveal the $(T-T_c)^{3/2}$ temperature dependence. The
coupling constant $\alpha$, as well as, chemical potential $\mu_D$ and the
velocity $S_D$ of the {\it dark matter}, affect the critical chemical potential
of the p-wave holographic $SU(2)$ system. On the other hand, $\alpha$, {\it
dark matter} velocity $S_D$ and density $\rho_D$ determine the actual value of
the transition temperature of the same superconductor/superfluid set up.
However, the {\it dark matter} does not affect the value of the current.


title: Bounds on the speed of sound in dense matter, and neutron star structure

abstract:
  The accurate determination of the maximum mass of the neutron stars is one of
the most important tasks in astrophysics. It is directly related to the
identification of the black holes in the universe, the production of neutron
stars from the supernovae explosion, and the equation of state (EoS) of dense
matter. However, not only the EoS is directly connected with neutron star
masses, but also the speed of sound in dense matter is a crucial quantity which
characterizes the stiffness of the EoS. The upper bound of the speed of sound
imposes strong constraints on the maximum mass of neutron stars. However, this
upper bound remains still an open issue. Recent observations, of binary neutron
star systems, offer the possibility of measuring with high accuracy both the
mass and the tidal polarizability of the stars. We study possible effects of
the upper bound of the speed of sound on the upper bound of the mass and the
tidal polarizability. We conclude that these kinds of measurements, combined
with recent observations of neutron stars with masses close to $2 M_{\odot}$,
will provide robust constraints on the equation of state of hadronic matter at
high densities.


title: Transverse multipolar light-matter couplings in evanescent waves

abstract:
  We present an approach to study the interaction between matter and evanescent
fields. The approach is based on the decomposition of evanescent plane waves
into multipoles of well-defined angular momentum transverse to both decay and
propagation directions. We use the approach to identify the origin of the
recently observed directional coupling of emitters into guided modes, and of
the opposite Zeeman state excitation of atoms near a fiber. We explain how to
rigorously quantify both effects, and show that the directionality and the
difference in excitation rates grow exponentially with the multipolar order of
the light-matter interaction. We also use the approach to study and maximize
the transverse torque exerted by an evanescent plane wave onto a given
spherical absorbing particle. The maximum occurs at the quadrupolar order of
the particle, and for a particular polarization of the plane wave. All the
obtained physical insights can be traced back to the two main features of the
decomposition of evanescent plane waves into transverse multipolar modes: A
polarization independent exponential dominance of modes with large transverse
angular momentum, and a polarization controlled parity selection rule.


title: Walksat stalls well below the satisfiability threshold

abstract:
  Partly on the basis of heuristic arguments from physics it has been suggested
that the performance of certain types of algorithms on random $k$-SAT formulas
is linked to phase transitions that affect the geometry of the set of
satisfying assignments. But beyond intuition there has been scant rigorous
evidence that "practical" algorithms are affected by these phase transitions.
In this paper we prove that \walksat, a popular randomised satisfiability
algorithm, fails on random $k$-SAT formulas not very far above clause/variable
density where the set of satisfying assignments shatters into tiny,
well-separated clusters. Specifically, we prove \walksat\ is ineffective with
high probability if $m/n>c2^k\ln^2k/k$, where $m$ is the number of clauses, $n$
is the number of variables and $c>0$ is an absolute constant. By comparison,
\walksat\ is known to find satisfying assignments in linear time \whp\ if
$m/n<c'2^k/k$ for another constant $c'>0$ [Coja-Oghlan and Frieze, SIAM J.\
Computing 2014].


title: Counting gluings of octahedra

abstract:
  Three--dimensional colored triangulations are gluings of tetrahedra whose
faces carry the colors 0, 1, 2, 3 and in which the attaching maps between
tetrahedra are defined using the colors. This framework makes it possible to
generalize the notion of two--dimensional $2p$--angulations to three dimensions
in a way which is suitable for combinatorics and enumeration. In particular,
universality classes of three--dimensional triangulations can be investigated
within this framework. Here we study colored triangulations obtained by gluing
octahedra. Those which maximize the number of edges at fixed number of
octahedra are fully characterized and are shown to have the topology of the
3--sphere. They are further shown to be in bijection with a family of trees, a
result which is confirmed by the exact enumeration.


title:
Enhanced thermoelectric performance in thin films of three-dimensional
  topological insulators

abstract:
  Thermoelectric (TE) devices have been attracting increasing attention because
of their ability to convert heat directly to electricity. To date, improving
the TE figure of merit remains the key challenge. The advent of the topological
insulator and the emerging nanotechnology open a new way to design
high-performance TE devices. In this paper, we investigate the TE transport
properties of the Bi2Se3 thin film by the first-principle calculations and the
Boltzmann transport theory. By comparing our calculations with the earlier
experimental data, we demonstrate that, for the Bi2Se3 film of thickness larger
than six quintuple layers, the relaxation time of the topological surface
states in the bulk gap is about hundreds of femtoseconds, which is about two
orders larger than that of the bulk states. Such a large relaxation-time
difference causes the ratio of the electrical conductance to the thermal
conductance much larger than the value predicted by the Wiedemann-Franz law, as
well as the large magnitude of Seebeck coefficient, and consequently the large
TE figure of merit, when the Fermi level is near the conduction band edge. We
shows that the TE performance can be further improved by introducing defects in
the middle layers of the thin film. The improvement is generally significant at
room temperature and can be further enhanced at higher temperature.


title: Off-Shell N=2 Linear Multiplets in Five Dimensions

abstract:
  We present a superconformal tensor calculus for an arbitrary number of five
dimensional N=2 linear multiplets. We also demonstrate how to construct higher
derivative invariants and higher order supersymmetric off-diagonal models.
Finally, we show the procedure required for the derivation of the
supersymmetric completion of the non-Abelian $F^4$ action.


title:
Frequency of Arrival-based Interference Localization Using a Single
  Satellite

abstract:
  Intentional and unintentional interferences are an increasing threat for the
satellite communications industry. In this paper, we aim to localize an
interference with unknown location using frequency of arrival (FoA) technique
by only relying on the measurements obtained through a single satellite. In
each time instance, the satellite samples the interference and forwards it to
the gateway to estimate its frequency. Since the satellite moves, each
estimated frequency includes a Doppler shift, which is related to the location
of the unknown interferer. The satellite's position, velocity, oscillator
frequency, and the interference frequency are used at the gateway to build a
location-related equation between the estimated frequency and the location of
the unknown interference. Simultaneously with the interference signal, the
satellite samples a reference signal to calibrate the estimated frequency and
compensate for the mismatches between the available and real values of the
satellite's position, velocity, and oscillator frequency. Multiple
location-related equations obtained based on the FoA measurements, (at least
two), along with the equation of the earth surface are used to localize the
unknown interference. Simulations show that increasing the number of these
equations, and the satellite velocity can improve the localization accuracy by
80% and 95%, respectively.


title: Accelerated Kaczmarz Algorithms using History Information

abstract:
  The Kaczmarz algorithm is a well known iterative method for solving
overdetermined linear systems. Its randomized version yields provably
exponential convergence in expectation. In this paper, we propose two new
methods to speed up the randomized Kaczmarz algorithm by utilizing the past
estimates in the iterations. The first one utilize the past estimates to get a
preconditioner. The second one combines the stochastic average gradient (SAG)
method with the randomized Kaczmarz algorithm. It takes advantage of past
gradients to improve the convergence speed. Numerical experiments indicate that
the new algorithms can dramatically outperform the standard randomized Kaczmarz
algorithm.


title: Spectral Efficiency of Mixed-ADC Receivers for Massive MIMO Systems

abstract:
  This paper investigated the uplink of multi-user massive multi-input
multi-output (MIMO) systems with a mixed analog-to-digital converter (ADC)
receiver architecture, in which some antennas are equipped with costly
full-resolution ADCs and others with less expensive low-resolution ADCs. A
closed-form approximation of the achievable spectral efficiency (SE) with the
maximum-ratio combining (MRC) detector is derived. Based on this approximated
result, the effects of the number of base station antennas, the transmit power,
the proportion of full-resolution ADCs in the mixed-ADC structure, and the
number of quantization bits of the low-resolution ADCs are revealed. Results
showcase that the achievable SE increases with the number of BS antennas and
quantization bits, and it converges to a saturated value in the high user power
regime or the full ADC resolution case. Most important, this work efficiency
verifies that for massive MIMO, the mixed-ADC receiver with a small fraction of
full-resolution ADCs can have comparable SE performance with the receiver with
all full-resolution ADCs but at a considerably lower hardware cost.


title: Entanglement Entropy in (3+1)-d Free $U(1)$ Gauge Theory

abstract:
  We consider the entanglement entropy for a free $U(1)$ theory in $3 + 1$
dimensions in the extended Hilbert space definition. By taking the continuum
limit carefully we obtain a replica trick path integral which calculates this
entanglement entropy. The path integral is gauge invariant, with a gauge fixing
delta function accompanied by a Faddeev-Popov determinant. For a spherical
region it follows that the result for the logarithmic term in the entanglement,
which is universal, is given by the $a$ anomaly coefficient. We also consider
the extractable part of the entanglement, which corresponds to the number of
Bell pairs which can be obtained from entanglement distillation or dilution.
For a spherical region we show that the coefficient of the logarithmic term for
the extractable part is different from the extended Hilbert space result. We
argue that the two results will differ in general, and this difference is
accounted for by a massless scalar living on the boundary of the region of
interest.


title: hdm: High-Dimensional Metrics

abstract:
  In this article the package High-dimensional Metrics (\texttt{hdm}) is
introduced. It is a collection of statistical methods for estimation and
quantification of uncertainty in high-dimensional approximately sparse models.
It focuses on providing confidence intervals and significance testing for
(possibly many) low-dimensional subcomponents of the high-dimensional parameter
vector. Efficient estimators and uniformly valid confidence intervals for
regression coefficients on target variables (e.g., treatment or policy
variable) in a high-dimensional approximately sparse regression model, for
average treatment effect (ATE) and average treatment effect for the treated
(ATET), as well for extensions of these parameters to the endogenous setting
are provided. Theory grounded, data-driven methods for selecting the
penalization parameter in Lasso regressions under heteroscedastic and
non-Gaussian errors are implemented. Moreover, joint/ simultaneous confidence
intervals for regression coefficients of a high-dimensional sparse regression
are implemented. Data sets which have been used in the literature and might be
useful for classroom demonstration and for testing new estimators are included.


title:
Gaussian-Schell analysis of the transverse spatial properties of
  high-harmonic beams

abstract:
  High harmonic generation (HHG) is an established means of producing coherent,
short wavelength, ultrafast pulses from a compact set-up. Table-top
high-harmonic sources are increasingly being used to image physical and
biological systems using emerging techniques such as coherent diffraction
imaging and ptychography. These novel imaging methods require coherent
illumination, and it is therefore important to both characterize the spatial
coherence of high-harmonic beams and understand the processes which limit this
property. Here we investigate the near- and far-field spatial properties of
high-harmonic radiation generated in a gas cell. The variation with harmonic
order of the intensity profile, wavefront curvature, and complex coherence
factor is measured in the far-field by the SCIMITAR technique. Using the
Gaussian-Schell model, the properties of the harmonic beam in the plane of
generation are deduced. Our results show that the order-dependence of the
harmonic spatial coherence is consistent with partial coherence induced by both
variation of the intensity-dependent dipole phase as well as finite spatial
coherence of the driving radiation. These findings are used to suggest ways in
which the coherence of harmonic beams could be increased further, which would
have direct benefits to imaging with high-harmonic radiation.


title: Some applications of Supercompact Extender Based Forcings to HOD

abstract:
  Supercompact extender based forcings are used to construct models with HOD
cardinal structure different from those of V. In particular, a model with all
regular uncountable cardinals measurable in HOD is constructed.


title: A generalization of the simulation theorem for semidirect products

abstract:
  We generalize a result of Hochman in two simultaneous directions: Instead of
realizing an effectively closed $\mathbb{Z}^d$ action as a factor of a
subaction of a $\mathbb{Z}^{d+2}$-SFT we realize an action of a finitely
generated group analogously in any semidirect product of the group with
$\mathbb{Z}^2$. Let $H$ be a finitely generated group and $G = \mathbb{Z}^2
\rtimes H$ a semidirect product. We show that for any effectively closed
$H$-dynamical system $(Y,f)$ where $Y$ is a Cantor set, there exists a
$G$-subshift of finite type $(X,\sigma)$ such that the $H$-subaction of
$(X,\sigma)$ is an extension of $(Y,f)$. In the case where $f$ is an expansive
action of a recursively presented group $H$, a subshift conjugated to $(Y,f)$
can be obtained as the $H$-projective subdynamics of a $G$-sofic subshift. As a
corollary, we obtain that $G$ admits a non-empty strongly aperiodic subshift of
finite type whenever the word problem of $H$ is decidable.


title: Simulating the classical XY model with a laser network

abstract:
  Drawing fair samples from the Boltzmann distribution of a statistical model
is a challenging task for modern digital computers. We propose a physical
implementation of a Boltzmann sampler for the classical XY model by using a
laser network. The XY spins are mapped onto the phases of multiple laser pulses
in a fiber ring cavity and the steady-state distribution of phases naturally
realizes the Boltzmann distribution of the corresponding XY model. We
experimentally implement the laser network by using an actively mode-locked
fiber laser with optical delay lines, and demonstrate Boltzmann sampling for a
one-dimensional XY ring.


title:
Discovering Latent States for Model Learning: Applying Sensorimotor
  Contingencies Theory and Predictive Processing to Model Context

abstract:
  Autonomous robots need to be able to adapt to unforeseen situations and to
acquire new skills through trial and error. Reinforcement learning in principle
offers a suitable methodological framework for this kind of autonomous
learning. However current computational reinforcement learning agents mostly
learn each individual skill entirely from scratch. How can we enable artificial
agents, such as robots, to acquire some form of generic knowledge, which they
could leverage for the learning of new skills? This paper argues that, like the
brain, the cognitive system of artificial agents has to develop a world model
to support adaptive behavior and learning. Inspiration is taken from two recent
developments in the cognitive science literature: predictive processing
theories of cognition, and the sensorimotor contingencies theory of perception.
Based on these, a hypothesis is formulated about what the content of
information might be that is encoded in an internal world model, and how an
agent could autonomously acquire it. A computational model is described to
formalize this hypothesis, and is evaluated in a series of simulation
experiments.


title:
The latest results from DICE (Detector Interferometric Calibration
  Experiment)

abstract:
  Theia is an astrometric mission proposed to ESA in 2014 for which one of the
scientific objectives is detecting Earth-like exoplanets in the habitable zone
of nearby solar-type stars. This objective requires the capability to measure
stellar centroids at the precision of 1e-5 pixel. Current state-of-the-art
methods for centroid estimation have reached a precision of about 3e-5 pixel at
two times Nyquist sampling, this was shown at the JPL by the VESTA experiment.
A metrology system was used to calibrate intra and inter pixel quantum
efficiency variations in order to correct pixelation errors. The Theia
consortium is operating a testbed in vacuum in order to achieve 1e-5 pixel
precision for the centroid estimation. The goal is to provide a proof of
concept for the precision requirement of the Theia spacecraft.
  The testbed consists of two main sub-systems. The first one produces pseudo
stars: a blackbody source is fed into a large core fiber and lights-up a
pinhole mask in the object plane, which is imaged by a mirror on the CCD. The
second sub-system is the metrology, it projects young fringes on the CCD. The
fringes are created by two single mode fibers facing the CCD and fixed on the
mirror. In this paper we present the latest experiments conducted and the
results obtained after a series of upgrades on the testbed was completed. The
calibration system yielded the pixel positions to an accuracy estimated at 4e-4
pixel. After including the pixel position information, an astrometric accuracy
of 6e-5 pixel was obtained, for a PSF motion over more than 5 pixels. In the
static mode (small jitter motion of less than 1e-3 pixel), a photon noise
limited precision of 3e-5 pixel was reached.


title: Fast and robust pushbroom hyperspectral imaging via DMD-based scanning

abstract:
  We describe a new pushbroom hyperspectral imaging device that has no macro
moving part. The main components of the proposed hyperspectral imager are a
digital micromirror device (DMD), a CMOS image sensor with no filter as the
spectral sensor, a CMOS color (RGB) image sensor as the auxiliary image sensor,
and a diffraction grating. Using the image sensor pair, the device can
simultaneously capture hyperspectral data as well as RGB images of the scene.
The RGB images captured by the auxiliary image sensor can facilitate geometric
co-registration of the hyperspectral image slices captured by the spectral
sensor. In addition, the information discernible from the RGB images can lead
to capturing the spectral data of only the regions of interest within the
scene. The proposed hyperspectral imaging architecture is cost-effective, fast,
and robust. It also enables a trade-off between resolution and speed. We have
built an initial prototype based on the proposed design. The prototype can
capture a hyperspectral image datacube with a spatial resolution of 192x192
pixels and a spectral resolution of 500 bands in less than thirty seconds.


title:
Thermoelectric properties of orthorhombic group IV-VI monolayers from
  the first-principles calculations

abstract:
  Two-dimensional (2D) materials may have potential applications in
thermoelectric devices. In this work, we systematically investigate the
thermoelectric properties of orthorhombic group IV-VI monolayers $\mathrm{AB}$
(A=Ge and Sn; B=S and Se) by the first-principles calculations and
semiclassical Boltzmann transport theory. The spin-orbit coupling (SOC) is
included to investigate their electronic transport, which produces observable
effects on power factor, especially for n-type doping. According to calculated
$ZT$, the four monolayers exhibit diverse anisotropic thermoelectric
properties, although they have similar hinge-like crystal structure. The GeS
along zigzag and armchair directions shows the strongest anisotropy, while SnS
and SnSe show mostly isotropic efficiency of thermoelectric conversion, which
can be understood by the strength of anisotropy of their respective power
factor, electronic and lattice thermal conductivities. Calculated results show
that $ZT$ for different carriers of n- and p-type has little difference for
GeS, SnS and SnSe. It is found that GeSe, SnS and SnSe show better
thermoelectric performance compared to GeS in n-type doping, and SnS and SnSe
exhibit higher efficiency of thermoelectric conversion in p-type doping.
Compared to a lot of 2D materials, orthorhombic group IV-VI monolayers
$\mathrm{AB}$ (A=Ge and Sn; B=S and Se) may possess better thermoelectric
performance due to higher power factor and lower thermal conductivity. Our work
would be beneficial to further experimental study.


title: Curvature-guided motility of microalgae in geometric confinement

abstract:
  Microorganisms, such as bacteria and microalgae, often live in habitats
consisting of a liquid phase and a plethora of interfaces. The precise ways in
which these motile microbes behave in their confined environment remain
unclear. Using experiments, Brownian dynamics simulations, and analytical
theory, we study the motility of a single Chlamydomonas microalga in an
isolated microhabitat with controlled geometric properties. We demonstrate how
the geometry of the habitat controls the cell's navigation in confinement. The
probability of finding the cell swimming near the boundary scales linearly with
the wall curvature, as seen for both circular and elliptical chambers. The
theory, utilizing an asymmetric dumbbell model of the cell and steric wall
interactions, captures this curvature-guided navigation quantitatively with no
free parameters.


title: Normality of general elephants on 3-fold terminal flips

abstract:
  We prove that the general elephant $E_{X^+}\in |-K_{X^+}|$ is normal where
$X--> X^+$ is a 3-fold terminal flip. Hence $E_{X^+}$ has at worst Du Val
singularities. As a corollary, there exists no non-Gorenstein singularity of
type $cE/2$, $cD/3$, nor $cAx/4$ on the flipped curve $C^+$.


title:
Rips filtrations for quasi-metric spaces and asymmetric functions with
  stability results

abstract:
  The Rips filtration over a finite metric space and its corresponding
persistent homology are prominent methods in TDA to summarise the shape of
data. Crucial to their use is the bottleneck stability result. A generalisation
of the Rips filtration to any symmetric function $f:X\times X\to \mathbb{R}$
was defined by Chazal, De Silva and Oudot, and they showed it was stable with
respect to the correspondence distortion distance. Allowing asymmetry, we
consider four different persistence modules. The first method is through
symmetrisation. For $a\in [0,1]$ we can construct a symmetric function
$sym_a(f)(x,y)=a \min \{d(x,y), d(y,x)\}+ (1-a)\max \{d(x,y), d(y,x)\}$. We can
then follow the apply the standard theory for symmetric functions and get
stability as a corollary. The second method is to construct a filtration of
ordered tuple complexes where tuple $(x_0, x_2, \ldots x_p)\in Rips^{dir}(X)_t$
if $d(x_i, x_j)\leq t$ for all $i\leq j$. These two methods have the same
persistent homology as the standard Rips filtration when applied to a metric
space, or more generally to a symmetric function. We consider two constructions
using a filtration of directed graphs. We have directed graphs $\{D(X)_t\}$,
where directed edges $x\to y$ are included in $D(X)_t$ whenever
$\max\{f(x,y),f(x,x),f(y,y)\}\leq t$. From this we construct a preorder where
$x\leq y$ if there is a path from $x$ to $y$ in $D(X)_t$. We build persistence
modules using the strongly connected components of the graphs $D(X)_t$, which
are the equivalence classes of the associated preorders. We consider
persistence modules using a generalisation of poset topology to preorders. The
Gromov-Hausdorff distance can be extended as a correspondence distortion
distance to set-function pairs. We prove that all these new constructions enjoy
the same stability results.


title:
Polarization basis tracking scheme for quantum key distribution with
  revealed sifted key bits

abstract:
  Calibration of the polarization basis between the transmitter and receiver is
an important task in quantum key distribution (QKD). An effective
polarization-basis tracking scheme will decrease the quantum bit error rate
(QBER) and improve the efficiency of a polarization encoding QKD system. In
this paper, we proposed a polarization-basis tracking scheme using only
unveiled sifted key bits while performing error correction by legitimate users,
rather than introducing additional reference light or interrupting the
transmission of quantum signals. A polarization-encoding fiber BB84 QKD
prototype was developed to examine the validity of this scheme. An average QBER
of 2.32% and a standard derivation of 0.87% have been obtained during 24 hours
of continuous operation.


title: Accelerating the Super-Resolution Convolutional Neural Network

abstract:
  As a successful deep model applied in image super-resolution (SR), the
Super-Resolution Convolutional Neural Network (SRCNN) has demonstrated superior
performance to the previous hand-crafted models either in speed and restoration
quality. However, the high computational cost still hinders it from practical
usage that demands real-time performance (24 fps). In this paper, we aim at
accelerating the current SRCNN, and propose a compact hourglass-shape CNN
structure for faster and better SR. We re-design the SRCNN structure mainly in
three aspects. First, we introduce a deconvolution layer at the end of the
network, then the mapping is learned directly from the original low-resolution
image (without interpolation) to the high-resolution one. Second, we
reformulate the mapping layer by shrinking the input feature dimension before
mapping and expanding back afterwards. Third, we adopt smaller filter sizes but
more mapping layers. The proposed model achieves a speed up of more than 40
times with even superior restoration quality. Further, we present the parameter
settings that can achieve real-time performance on a generic CPU while still
maintaining good performance. A corresponding transfer strategy is also
proposed for fast training and testing across different upscaling factors.


title: Parity violation in the CMB trispectrum from the scalar sector

abstract:
  Under the existence of chiral non-Gaussian sources during inflation, the
trispectrum of primordial curvature perturbations can break parity. We examine
signatures of the induced trispectrum of the cosmic microwave background (CMB)
anisotropies. It is confirmed via a harmonic-space analysis that, as a
consequence of parity violation, such a CMB trispectrum has nonvanishing signal
in the $\ell_1 + \ell_2 + \ell_3 + \ell_4 = \text{odd}$ domain, which is
prohibited in the concordance cosmology. When the curvature trispectrum is
parametrized with Legendre polynomials, the CMB signal due to the Legendre
dipolar term is enhanced at the squeezed configurations in $\ell$ space,
yielding a high signal-to-noise ratio. A Fisher matrix computation results in a
minimum detectable size of the dipolar coefficient in a
cosmic-variance-limited-level temperature survey as $d_1^{\rm odd} = 640$. In
an inflationary model where the inflaton field couples to the gauge field via
an $f(\phi)(F^2 + F\tilde{F})$ interaction, the curvature trispectrum contains
such a parity-odd dipolar term. We find that, in this model, the CMB
trispectrum yields a high signal-to-noise ratio compared with the CMB power
spectrum or bispectrum. Therefore, the $\ell_1 + \ell_2 + \ell_3 + \ell_4 =
\text{odd}$ signal could be a promising observable of cosmological parity
violation.


title: Analytic Asymptotic Solution to Spherical Relativistic Shock Breakout

abstract:
  We investigate the relativistic breakout of a shock wave from the surface of
a star. In this process, each fluid shell is endowed with some kinetic and
thermal energy by the shock, and then continues to accelerate adiabatically by
converting thermal energy into kinetic energy. This problem has been previously
studied for a mildly relativistic breakout, where the acceleration ends close
to the surface of the star. The current work focuses on the case where the
acceleration ends at distances much greater than the radius of the star. We
derive an analytic description for the hydrodynamic evolution of the ejecta in
this regime, and validate it using a numerical simulation. We also provide
predictions for the expected light curves and spectra from such an explosion.
The relevance to astrophysical explosions is discussed, and it is shown that
such events require more energy than is currently believed to result from
astrophysical explosions.


title: Halo Occupation Distribution of Infrared Selected Quasars

abstract:
  We perform a Halo Occupation Distribution (HOD) modeling of the projected
two-point correlation function (2PCF) of quasars that are observed in the
Wide-field Infrared Survey Explorer (WISE) telescope with counter-parts in the
Sloan Digital Sky Survey (SDSS) Data Release (DR)-8 quasar catalog at a median
redshift of $z\sim 1.04 (\pm 0.58)$. Using a four parameter HOD model we derive
the host mass scales of WISE selected quasars. Our results show that the median
halo masses of central and satellite quasars lie in the range $M_{\mathrm{cen}}
= (5 \pm 1.0) \times 10^{12} M_{\odot}$ and $M_{\mathrm{sat}} = 8 (^{+7.8}
_{-4.8}) \times 10^{13} M_{\odot}$, respectively. The derived satellite
fraction is $f_{\mathrm{sat}}= 5.5 (^{+35} _{-5.0})\times 10^{-3}$. Previously
Richardson et al.\ used the SDSS DR7 quasar clustering data to obtain the halo
mass distributions of $z\sim 1.4$ quasars. Our results on the HOD of central
quasars are in excellent agreement with Richardson et al.\ but the host mass
scale of satellite quasars for the WISE sample, is lower than that of
Richardson et al.\ resulting in an order of magnitude higher satellite fraction
for the WISE sample. We note that our sample of quasars are systematically
brighter in the WISE frequency bands compared to the full quasar sample of
SDSS. We discuss the implication of this result in the context of current
theories of galaxy evolution.


title:
Universal Form of Stochastic Evolution for Slow Variables in Equilibrium
  Systems

abstract:
  Nonlinear, multiplicative Langevin equations for a complete set of slow
variables in equilibrium systems are generally derived on the basis of the
separation of time scales. The form of the equations is universal and
equivalent to that obtained by Green. An equation with a nonlinear friction
term for Brownian motion turns out to be an example of the general results. A
key method in our derivation is to use different discretization schemes in a
path integral formulation and the corresponding Langevin equation, which also
leads to a consistent understanding of apparently different expressions for the
path integral in previous studies.


title: Constraining the EoR model parameters with the 21cm bispectrum

abstract:
  We perform a Fisher analysis to estimate the expected constraints on the
Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature,
the ionizing efficiency and the mean free path of ionizing photons) taking into
account the thermal noise of the exisitting telescopes, MWA and LOFAR. We
consider how the inclusion of the 21cm bispectrum improves the constraints
compared to using the power spectrum alone. Assuming that we perfectly remove
the foreground, we found that the bispectrum, which is calculated by the
21cmFAST code, can constrain the EoR model parameters more tightly than the
power spectrum since the bispectrum is more sensitive to the EoR model
parameters than the power spectrum. We also found that degeneracy between the
EoR model parameters can be broken by combining the bispectrum with the power
spectrum.


title:
The spectral excess theorem for graphs with few eigenvalues whose
  distance-$2$ or distance-$1$-or-$2$ graph is strongly regular

abstract:
  We study regular graphs whose distance-$2$ graph or distance-$1$-or-$2$ graph
is strongly regular. We provide a characterization of such graphs $\Gamma$
(among regular graphs with few distinct eigenvalues) in terms of the spectrum
and the mean number of vertices at maximal distance $d$ from every vertex,
where $d+1$ is the number of different eigenvalues of $\Gamma$. This can be
seen as a another version of the so-called spectral excess theorem, which
characterizes in a similar way those regular graphs that are distance-regular.


title:
Error regions in quantum state tomography: computational complexity
  caused by geometry of quantum states

abstract:
  The outcomes of quantum mechanical experiments are inherently random. It is
therefore necessary to develop stringent methods for quantifying the degree of
statistical uncertainty about the results of quantum experiments. For the
particularly relevant task of quantum state estimation, it has been shown that
a significant reduction in uncertainty can be achieved by taking the positivity
of quantum states into account. However -- the large number of partial results
and heuristics notwithstanding -- no efficient general algorithm is known that
produces an optimal uncertainty region from experimental data and the prior
constraint of positivity. Here, we make this problem precise and show that the
general case is NP-hard. Our result leaves room for the existence of efficient
approximate solutions, and therefore does not yet imply that the practical task
of quantum uncertainty quantification is intractable. However, it does show
that there exists a non-trivial trade-off between optimality and computational
efficiency for error regions. We prove two versions of the result: One for
frequentist and one for Bayesian statistics.


title: Hiding Individuals and Communities in a Social Network

abstract:
  The Internet and social media have fueled enormous interest in social network
analysis. New tools continue to be developed and used to analyse our personal
connections, with particular emphasis on detecting communities or identifying
key individuals in a social network. This raises privacy concerns that are
likely to exacerbate in the future. With this in mind, we ask the question: Can
individuals or groups actively manage their connections to evade social network
analysis tools?
  By addressing this question, the general public may better protect their
privacy, oppressed activist groups may better conceal their existence, and
security agencies may better understand how terrorists escape detection. We
first study how an individual can evade "network centrality" analysis without
compromising his or her influence within the network. We prove that an optimal
solution to this problem is hard to compute. Despite this hardness, we
demonstrate that even a simple heuristic, whereby attention is restricted to
the individual's immediate neighbourhood, can be surprisingly effective in
practice. For instance, it could disguise Mohamed Atta's leading position
within the WTC terrorist network, and that is by rewiring a strikingly-small
number of connections. Next, we study how a community can increase the
likelihood of being overlooked by community-detection algorithms. We propose a
measure of concealment, expressing how well a community is hidden, and use it
to demonstrate the effectiveness of a simple heuristic, whereby members of the
community either "unfriend" certain other members, or "befriend" some
non-members, in a coordinated effort to camouflage their community.


title: On ampleness of canonical bundle

abstract:
  We study projective manifolds with nonamenable and non-residually finite
fundamental groups. We generalize the uniformization theorem of our earlier
note. We generalize a classical theorem of Maltsev about finitely generated
subgroups of GL(m).


title:
Interferometric Motion Detection in Atomic Layer 2D Nanostructures:
  Visualizing Signal Transduction Efficiency and Optimization Pathways

abstract:
  Atomic layer crystals are emerging building blocks for enabling new
two-dimensional (2D) nanomechanical systems, whose motions can be coupled to
other attractive physical properties in such 2D systems. Optical interferometry
has been very effective in reading out the infinitesimal motions of these 2D
structures and spatially resolving different modes. To quantitatively
understand the detection efficiency and its dependence on the device parameters
and interferometric conditions, here we present a systematic study of the
intrinsic motion responsivity in 2D nanomechanical systems using a
Fresnel-law-based model. We find that in monolayer to 14-layer structures, MoS2
offers the highest responsivity among graphene, h-BN, and MoS2 devices and for
the three commonly used visible laser wavelengths (633, 532, and 405nm). We
also find that the vacuum gap resulting from the widely used 300nm-oxide
substrate in making 2D devices, fortunately, leads to close-to-optimal
responsivity for a wide range of 2D flakes. Our results elucidate and
graphically visualize the dependence of motion transduction responsivity upon
2D material type and number of layers, vacuum gap, oxide thickness, and
detecting wavelength, thus providing design guidelines for constructing 2D
nanomechanical systems with optimal optical motion readout.


title:
General finite-size effects for zero-entropy states in one-dimensional
  quantum integrable models

abstract:
  We present a general derivation of the spectrum of excitations for gapless
states of zero entropy density in Bethe ansatz solvable models. Our formalism
is valid for an arbitrary choice of bare energy function which is relevant to
situations where the Hamiltonian for time evolution differs from the
Hamiltonian in a (generalized) Gibbs ensemble, i.e. out of equilibrium. The
energy of particle and hole excitations, as measured with the time-evolution
Hamiltonian, is shown to include additional contributions stemming from the
shifts of the Fermi points that may now have finite energy. The finite-size
effects are also derived and the connection with conformal field theory
discussed. The critical exponents can still be obtained from the finite-size
spectrum, however the velocity occurring here differs from the one in the
constant Casimir term. The derivation highlights the importance of the phase
shifts at the Fermi points for the critical exponents of asymptotes of
correlations. We generalize certain results known for the ground state and
discuss the relation to the dressed charge (matrix). Finally, we discuss the
finite-size corrections in the presence of an additional particle or hole which
are important for dynamical correlation functions.


title:
Functional renormalization group for the $U(1)$-$T_5^6$ tensorial group
  field theory with closure constraint

abstract:
  This paper is focused on the functional renormalization group applied to the
$T_5^6$ tensor model on the Abelian group $U(1)$ with closure constraint. For
the first time, we derive the flow equations for the couplings and mass
parameters in a suitable truncation around the marginal interactions with
respect to the perturbative power counting. For the second time, we study the
behavior around the Gaussian fixed point, and show that the theory is
nonasymptotically free. Finally, we discuss the UV completion of the theory. We
show the existence of several nontrivial fixed points, study the behavior of
the renormalization group flow around them, and point out evidence in favor of
an asymptotically safe theory.


title: Magnetism in Sr$_{2}$CrMoO$_{6}$: A combined abinitio and model study

abstract:
  Using a combination of first-principles density functional theory (DFT)
calculations and exact diagonalization studies of a first-principles derived
model, we carry out a microscopic analysis of the magnetic properties of the
half-metallic double perovskite compound, Sr$_2$CrMoO$_6$, a sister compound of
the much discussed material Sr$_2$FeMoO$_6$. The electronic structure of
Sr$_2$CrMoO$_6$, though appears similar to Sr$_2$FeMoO$_6$ at first glance,
shows non trivial differences with that of Sr$_2$FeMoO$_6$ on closer
examination. In this context, our study highlights the importance of charge
transfer energy between the two transition metal sites. The change in charge
transfer energy due to shift of Cr $d$ states in Sr$_2$CrMoO$_6$ compared to Fe
$d$ in Sr$_2$FeMoO$_6$ suppresses the hybridization between Cr $t_{2g}$ and Mo
$t_{2g}$. This strongly weakens the hybridization-driven mechanism of magnetism
discussed for Sr$_2$FeMoO$_6$. Our study reveals that, nonetheless, the
magnetic transition temperature of Sr$_2$CrMoO$_6$ remains high since
additional superexchange contribution to magnetism arises with a finite
intrinsic moment developed at the Mo site. We further discuss the situation in
comparison to another related double perovskite compound, Sr$_2$CrWO$_6$. We
also examine the effect of correlation beyond DFT, using dynamical mean field
theory (DMFT).


title:
A New Performance Guarantee for Orthogonal Matching Pursuit Using Mutual
  Coherence

abstract:
  In this paper we present a new coherence-based performance guarantee for the
Orthogonal Matching Pursuit (OMP) algorithm. An upper bound for the probability
of correctly identifying the support of a sparse signal with additive white
Gaussian noise is derived. Compared to previous work, the new bound takes into
account the signal parameters such as dynamic range, noise variance, and
sparsity. Numerical simulations show significant improvements over previous
work.


title:
Double Higgcision: 125 GeV Higgs boson and a potential diphoton
  Resonance

abstract:
  Searches for diphoton resonance have been shown to be very useful in
discovering new heavy spin-0 or spin-2 particles. Supposing that a new heavy
particle shows up in the diphoton channel and it points to a spin-0 boson, it
can be allowed to have a small mixing with the observed 125 GeV Higgs-like
boson. We borrow the example of the 750 GeV particles hinted with 3.2 fb$^{-1}$
data at the end of 2015 (though it did not appear in the 2016 data) to perform
an analysis of "double Higgcision". In this work, we perform a complete
Higgs-signal strength analysis in the Higgs-portal type framework, using all
the existing 125 GeV Higgs boson data as well as the diphoton signal strength
of the 750 GeV scalar boson. The best fit prefers a very tiny mixing between
two scalar bosons, which has to be accommodated in models for the 750 GeV
scalar boson.


title: Universal Bound on Sampling Bosons in Linear Optics

abstract:
  In linear optics, photons are scattered in a network through passive optical
elements including beamsplitters and phase shifters, leading to many intriguing
applications in physics, such as Mach-Zehnder interferometry, Hong-Ou-Mandel
effect, and tests of fundamental quantum mechanics. Here we present a general
analytic expression governing the upper limit of the transition amplitudes in
sampling bosons, through all realizable linear optics. Apart from boson
sampling, this transition bound results in many other interesting applications,
including behaviors of Bose-Einstein Condensates (BEC) in optical networks,
counterparts of Hong-Ou-Mandel effects for multiple photons, and approximating
permanents of matrices. Also, this general bound implies the existence of a
polynomial-time randomized algorithm for estimating transition amplitudes of
bosons, which represents a solution to an open problem raised by Aaronson and
Hance in 2012.

categories: quant-ph math-ph math.MP physics.comp-ph physics.optics


title: On the homotopy exact sequence for log algebraic fundamental groups

abstract:
  We construct a log algebraic version of the homotopy sequence for a
quasi-projective normal crossing log variety over a log point of characteristic
zero and prove some exactness properties of it. Our proofs are purely
algebraic.


title:
Generation of a cold pulsed beam of Rb atoms by transfer from a 3D
  magneto-optic trap

abstract:
  We demonstrate a technique for producing a cold pulsed beam of atoms by
transferring a cloud of atoms trapped in a three dimensional magneto-optic trap
(MOT). The MOT is loaded by heating a getter source of Rb atoms. We show that
it is advantageous to transfer with two beams (with a small angle between them)
compared to a single beam, because the atoms stop interacting with the beams in
the two-beam technique, which results in a Gaussian velocity distribution. The
atoms are further cooled in optical molasses by turning off the MOT magnetic
field before the transfer beams are turned on.


title:
The numerical simulation tool for the MAORY multiconjugate adaptive
  optics system

abstract:
  The Multiconjugate Adaptive Optics RelaY (MAORY) is and Adaptive Optics
module to be mounted on the ESO European-Extremely Large Telescope (E-ELT). It
is a hybrid Natural and Laser Guide System that will perform the correction of
the atmospheric turbulence volume above the telescope feeding the Multi-AO
Imaging Camera for Deep Observations Near Infrared spectro-imager (MICADO). We
developed an end-to-end Monte- Carlo adaptive optics simulation tool to
investigate the performance of a the MAORY and the calibration, acquisition,
operation strategies. MAORY will implement Multiconjugate Adaptive Optics
combining Laser Guide Stars (LGS) and Natural Guide Stars (NGS) measurements.
The simulation tool implements the various aspect of the MAORY in an end to end
fashion. The code has been developed using IDL and uses libraries in C++ and
CUDA for efficiency improvements. Here we recall the code architecture, we
describe the modeled instrument components and the control strategies
implemented in the code.


title:
An interacting quark-diquark model. Strange and nonstrange baryon
  spectroscopy and other observables

abstract:
  We describe the relativistic interacting quark-diquark model formalism and
its application to the calculation of strange and nonstrange baryon spectra.
The results are compared to the existing experimental data. We also discuss the
application of the model to the calculation of other baryon observables, like
baryon magnetic moments, open-flavor strong decays and baryon masses with
self-energy corrections.


title:
Controlling almost-invariant halfspaces in both real and complex
  settings

abstract:
  If $T$ is a bounded linear operator acting on an infinite-dimensional Banach
space $X$, we say that a closed subspace $Y$ of $X$ of both infinite dimension
and codimension is an almost-invariant halfspace (AIHS) under $T$ whenever
$TY\subseteq Y+E$ for some finite-dimensional subspace $E$, or, equivalently,
$(T+F)Y\subseteq Y$ for some finite-rank perturbation $F:X\to X$. We discuss
the existence of AIHS's for various restrictions on $E$ and $F$ when $X$ is a
complex Banach space. We also extend some of these and other results in the
literature to the setting where $X$ is a real Banach space instead of a complex
one.


title:
Phase estimation of phase shifts in two arms for an SU(1,1)
  interferometer with coherent and squeezed vacuum states

abstract:
  We theoretically present the quantum Cram\'{e}r-Rao bounds (QCRB) of an
SU(1,1) interferometer for Gaussian states input with and without the internal
photonic losses. The phase shifts in the single arm and in the double arms are
studied and the corresponding analytical expressions of quantum Fisher
information with Gaussian input states are presented. Different from the
traditional Mach-Zehnder interferometer, the QCRB of single arm case is
slightly higher or lower than that of double arms case depending on the input
states. With a fixed mean photon number and for pure Gaussian state input, the
optimal sensitivity is achieved with a squeezed vacuum input in one mode and
the vacuum input in the other. We compare the QCRB with the standard quantum
limit and Heisenberg limit. In the case of small internal losses the QCRB can
beat the standard quantum limit.


title:
Sparse aperture differential piston measurements using the pyramid
  wave-front sensor

abstract:
  In this paper we report on the laboratory experiment we settled in the
Shanghai Astronomical Observatory (SHAO) to investigate the pyramid wavefront
sensor (WFS) ability to measure the differential piston on a sparse aperture.
The ultimate goal is to verify the ability of the pyramid WFS work in closed
loop to perform the phasing of the primary mirrors of a sparse Fizeau imaging
telescope. In the experiment we installed on the optical bench we performed
various test checking the ability to flat the wave-front using a deformable
mirror and to measure the signal of the differential piston on a two pupils
setup. These steps represent the background from which we start to perform full
closed loop operation on multiple apertures. These steps were also useful to
characterize the achromatic double pyramids (double prisms) manufactured in the
SHAO optical workshop.


title: Dark tip-tilt sensing

abstract:
  Dark wavefront sensing in its simplest and more crude form is a quad-cell
with a round spot of dark ink acting as occulting disk at the center. This
sensor exhibits fainter limiting magnitude than a conventional quad-cell,
providing that the size of the occulting disk is slightly smaller than the size
of the spot and smaller than the residual jitter movement in closed loop. We
present simulations focusing a generic Adaptive Optics system using Natural
Guide Stars to provide the tip-tilt signal. We consider a jitter spectrum of
the residual correction including amplitudes exceeding the dark disk size.


title: Noncommutative Iwasawa theory arising from Hecke algebras

abstract:
  Let $p$ be an odd prime and $f$ be a nearly ordinary Hilbert modular Hecke
eigenform defined over a totally real field $F$. Let $\mathbb{I}$ be an
irreducible component of the universal nearly ordinary or locally cyclotomic
deformation of the representation of $\mathrm{Gal}_F$ that is associated to
$f$. We study the deformation rings over a $p$-adic Lie extension $F_\infty$
that contains the cyclotomic $\mathbb{Z}_p$-extension of $F$. More precisely,
we prove a control theorem about these rings. We introduce a category
$\mathfrak{M}_{\mathcal H}^{\mathbb I}(\mathcal G)$, where $\mathcal
G=\mathrm{Gal}(F_\infty/F)$ and $\mathcal H=\mathrm{Gal}(F_\infty/F_{cyc})$,
which is the category of modules which are torsion with respect to a certain
Ore set, which generalizes the Ore set introduced by Venjakob. For Selmer
groups which are in this category, we formulate a Main conjecture in the spirit
of Noncommutative Iwasawa theory. We then set up a strategy to prove the
conjecture by generalizing work of Burns, Kato, Kakde, and Ritter and Weiss.
This requires appropriate generalizations of results of Oliver and Taylor, and
Oliver on Logarithms of certain $K$-groups, which we have presented here.


title:
Search for 511 keV Emission in Satellite Galaxies of the Milky Way with
  INTEGRAL/SPI

abstract:
  The positron annihilation gamma-ray signal in the Milky Way (MW) shows a
puzzling morphology: a very bright bulge and a very low surface-brightness
disk. A coherent explanation of the positron origin, propagation through the
Galaxy and subsequent annihilation in the interstellar medium has not yet been
found. Tentative explanations involve positrons from radioactivity, X-ray
binaries, and dark matter (DM). Dwarf satellite galaxies (DSGs) are believed to
be DM-dominated and hence promising candidates in the search for 511 keV
emission as a result of DM annihilation into electron-positron pairs. The goal
of this study is to constrain possible 511 keV gamma-ray signals from 39 DSGs
of the MW and to test the annihilating DM scenario. We use the spectrometer SPI
on INTEGRAL to extract individual spectra for the studied objects. As the
diffuse galactic emission dominates the signal, the large scale morphology of
the MW has been modelled accordingly and was included in a maximum likelihood
analysis. Alternatively, a distance-weighted stacked spectrum has been
determined. Only Reticulum II (Ret II) shows a 3.1 sigma signal. Five other
sources show tentative 2 sigma signals. The mass-to-511-keV-luminosity-ratio
shows a marginal trend towards higher values for intrinsically brighter
objects, opposite to the V band mass-to-light-ratio, which is generally used to
uncover DM in DSGs. All derived flux values are above the level implied by a DM
interpretation of the MW bulge signal. The signal from Ret II is unlikely to be
related to a DM origin alone, otherwise, the MW bulge would be about 100 times
brighter than what is seen. Ret II is exceptional considering the DSG sample,
and rather points to enhanced recent star formation activity, if its origins
are similar to processes in the MW. Understanding this emission may provide
further clues regarding the origin of the annihilation emission in the MW.


title: The hard-edge tacnode process for Brownian motion

abstract:
  We consider $N$ non-intersecting Brownian bridges conditioned to stay below a
fixed threshold. We consider a scaling limit where the limit shape is
tangential to the threshold. In the large $N$ limit, we determine the limiting
distribution of the top Brownian bridge conditioned to stay below a function as
well as the limiting correlation kernel of the system. It is a one-parameter
family of processes which depends on the tuning of the threshold position on
the natural fluctuation scale. We also discuss the relation to the six-vertex
model and to the Aztec diamond on restricted domains.


title: High order dark wavefront sensing simulations

abstract:
  Dark wavefront sensing takes shape following quantum mechanics concepts in
which one is able to "see" an object in one path of a two-arm interferometer
using an as low as desired amount of light actually "hitting" the occulting
object. A theoretical way to achieve such a goal, but in the realm of wavefront
sensing, is represented by a combination of two unequal beams interferometer
sharing the same incoming light, and whose difference in path length is
continuously adjusted in order to show different signals for different signs of
the incoming perturbation. Furthermore, in order to obtain this in white light,
the path difference should be properly adjusted vs the wavelength used. While
we incidentally describe how this could be achieved in a true optomechanical
setup, we focus our attention to the simulation of a hypothetical "perfect"
dark wavefront sensor of this kind in which white light compensation is
accomplished in a perfect manner and the gain is selectable in a numerical
fashion. Although this would represent a sort of idealized dark wavefront
sensor that would probably be hard to match in the real glass and metal, it
would also give a firm indication of the maximum achievable gain or, in other
words, of the prize for achieving such device. Details of how the simulation
code works and first numerical results are outlined along with the perspective
for an in-depth analysis of the performances and its extension to more
realistic situations, including various sources of additional noise.


title:
The first four-color photometric investigation of the W UMa type contact
  binary V868 Mon

abstract:
  The first four-color light curves of V868 Mon in the $B$ $V$ $R_c$ and $I_c$
bands are presented and analyzed by using the Wilson-Devinney method of the
2013 version. It is discovered that V868 Mon is an A-subtype contact binary
(f=$58.9\,\%$) with a large temperature difference of 916$K$ between the two
components. Using the eight new times of light minimum determined by the
authors together with those collected from literatures, the authors found that
the general trend of the observed-calculate ($O$-$C$) curve shows a upward
parabolic variation that corresponds to a long-term increase in the orbital
period at a rate of $dP/dt=9.38\times{10^{-7}}day\cdot year^{-1}$. The
continuous increase may be caused by a mass transfer from the less massive
component to the more massive one.


title:
The Borsuk-Ulam property for homotopy classes of selfmaps of surfaces of
  Euler characteristic zero

abstract:
  Let M and N be topological spaces such that M admits a free involution
$\\tau$. A homotopy class $\beta$ $\in$ [M, N ] is said to have the Borsuk-Ulam
property with respect to $\\tau$ if for every representative map f : M
$\rightarrow$ N of $\beta$, there exists a point x $\in$ M such that f ($\\tau$
(x)) = f (x). In the case where M is a compact, connected manifold without
boundary and N is a compact, connected surface without boundary different from
the 2-sphere and the real projective plane, we formulate this property in terms
of the pure and full 2-string braid groups of N , and of the fundamental groups
of M and the orbit space of M with respect to the action of $\\tau$. If M = N
is either the 2-torus T^2 or the Klein bottle K^2 , we then solve the problem
of deciding which homotopy classes of [M, M ] have the Borsuk-Ulam property.
First, if $\\tau$ : T^2 $\rightarrow$ T^2 is a free involution that preserves
orientation, we show that no homotopy class of [T^2 , T^2 ] has the Borsuk-Ulam
property with respect to $\\tau$. Secondly, we prove that up to a certain
equivalence relation, there is only one class of free involutions $\\tau$ : T^2
$\rightarrow$ T^2 that reverse orientation, and for such involutions, we
classify the homotopy classes in [T^2 , T^2 ] that have the Borsuk-Ulam
property with respect to $\\tau$ in terms of the induced homomorphism on the
fundamental group. Finally, we show that if $\\tau$ : K^2 $\rightarrow$ K^2 is
a free involution, then a homotopy class of [K^2 , K^2 ] has the Borsuk-Ulam
property with respect to $\\tau$ if and only if the given homotopy class lifts
to the torus.


title:
The Photometric Investigation of V921 Her using the Lunar-based
  Ultraviolet Telescope of Chang'e-3 mission

abstract:
  The light curve of V921 Her in ultraviolet band observed by the Lunar-based
Ultraviolet Telescope (LUT) is analyzed by the Wilson-Devinney code. Our
solutions conclude that V921 Her is an early type marginal contact binary
system with an additional close-in component. The binary system is under poor
thermal contact with a temperature difference of nearly $700K$ between the two
components. The close-in component contributes about $19\,\%$ of the total
luminosity in the triple system. Combining the radial velocity study together
with our photometric solutions, the mass of the primary star and secondary one
are calculated to be $M_1 = 1.784(\pm0.055)M_\odot$, $M_2 =
0.403(\pm0.012)M_\odot$. The evolutionary scenario of V921 Her is discussed.
All times of light minimum of V921 Her available in the bibliography are taken
into account and the $O - C$ curve is analyzed for the first time. The most
probable fitting results are discussed in the paper, which also confirm the
existence of a third component ($P_3=10.2$ year) around the binary system. The
period of V921 Her is also undergoing a continuously rapid increase at a rate
of $dP/dt=+2.79\times{10^{-7}}day\cdot year^{-1}$, which may due to mass
transfer from the less massive component to the more massive one.


title: Eigenvalue Dynamics for Multimatrix Models

abstract:
  By performing explicit computations of correlation functions, we find
evidence that there is a sector of the two matrix model defined by the $SU(2)$
sector of ${\cal N}=4$ super Yang-Mills theory, that can be reduced to
eigenvalue dynamics. There is an interesting generalization of the usual Van
der Monde determinant that plays a role. The observables we study are the BPS
operators of the $SU(2)$ sector and include traces of products of both
matrices, which are genuine multi matrix observables. These operators are
associated to supergravity solutions of string theory.


title: Reconstruction of interaction rate in Holographic dark energy

abstract:
  The present work is based on the holographic dark energy model with Hubble
horizon as the infrared cut-off. The interaction rate between dark energy and
dark matter has been reconstructed for three different parameterizations of the
deceleration parameter. Observational constraints on the model parameters have
been obtained by maximum likelihood analysis using the observational Hubble
parameter data (OHD), type Ia supernovab data (SNe), baryon acoustic
oscillation data (BAO) and the distance prior of cosmic microwave background
(CMB) namely the CMB shift parameter data (CMBShift). The interaction rate
obtained in the present work remains always positive and increases with
expansion. It is very similar to the result obtained in previous findings where
the interaction rate has been reconstructed for a parametrization of the dark
energy equation of state. Tighter constraints on the interaction rate have been
obtained in the present work as it is based on larger data sets. The nature of
the dark energy equation of state parameter has also been studied for the
present models. Though the reconstruction is done from different
parametrizations, the overall nature of the interaction rate is very similar in
all the cases. Different information criteria and the Bayesian evidence, which
have been invoked in the context of model selection, show that the these models
are at close proximity of each other.


title: A global perspective to connections on principal 2-bundles

abstract:
  For a strict Lie 2-group, we develop a notion of Lie 2-algebra-valued
differential forms on Lie groupoids, furnishing a differential
graded-commutative Lie algebra equipped with an adjoint action of the Lie
2-group and a pullback operation along Morita equivalences between Lie
groupoids. Using this notion, we define connections on principal 2-bundles as
Lie 2-algebra-valued 1-forms on the total space Lie groupoid of the 2-bundle,
satisfying a condition in complete analogy to connections on ordinary principal
bundles. We carefully treat various notions of curvature, and prove a
classification result by the non-abelian differential cohomology of
Breen-Messing. This provides a consistent, global perspective to higher gauge
theory.


title: Landau-Khalatnikov phonon damping in strongly interacting Fermi gases

abstract:
  We derive the phonon damping rate due to the four-phonon Landau-Khalatnikov
process in low temperature strongly interacting Fermi gases using quantum
hydrodynamics, correcting and extending the original calculation of Landau and
Khalatnikov [ZhETF, 19 (1949) 637]. Our predictions can be tested in
state-of-the-art experiments with cold atomic gases in the collisionless
regime.


title:
Unitary boson-boson and boson-fermion mixtures: third virial coefficient
  and three-body parameter on a narrow Feshbach resonance

abstract:
  We give exact integral expressions of the third cluster or virial
coefficients of binary mixtures of ideal Bose or Fermi gases, with interspecies
interactions of zero range and infinite s-wave scattering length. In general
the result depends on three-body parameters Rt appearing in three-body contact
conditions, because an Efimov effect is present or because the mixture is in a
preefimovian regime with a mass ratio close to an Efimov effect threshold. We
give a new, exact integral expression of Rt for the microscopic narrow Feshbach
resonance model. A divergence of Rt in the preefimovian regime at a scaling
exponent s = 1/2 is predicted and physically discussed. The analytical results
are applied to typical species used in cold atom experiments.


title:
Magnetic relaxation phenomena in the Chiral Magnet Fe$_{1-x}$Co$_x$Si:
  An ac susceptibility study

abstract:
  We present a systematic study of the ac susceptibility of the chiral magnet
Fe$_{1-x}$Co$_x$Si with $x$ = 0.30 covering four orders of magnitude in
frequencies from 0.1 Hz to 1 kHz, with particular emphasis to the pronounced
history dependence. Characteristic relaxation times ranging from a few
milliseconds to tens of seconds are observed around the skyrmion lattice
A-phase, the helical-to-conical transition and in a region above $T_C$. The
distribution of relaxation frequencies around the A-phase is broad, asymmetric
and originates from multiple coexisting relaxation processes. The pronounced
dependence of the magnetic phase diagram on the magnetic history and cooling
rates as well as the asymmetric frequency dependence and slow dynamics suggest
more complicated physical phenomena in Fe$_{0.7}$Co$_{0.3}$Si than in other
chiral magnets.


title: A balance for Dark Matter bound states

abstract:
  Massive particles with self interactions of the order of 0.2 barn/GeV are
intriguing Dark Matter candidates from an astrophysical point of view. Current
and past experiments for direct detection of massive Dark Matter particles are
focusing to relatively low cross sections with ordinary matter, however they
cannot rule out very large cross sections, $\sigma/M > 0.01$ barn/GeV, due to
atmosphere and material shielding. Cosmology places a strong indirect limit for
the presence of large interactions among Dark Matter and baryons in the
Universe, however such a limit cannot rule out the existence of a small
sub-dominant component of Dark Matter with non negligible interactions with
ordinary matter in our galactic halo. Here, the possibility of the existence of
bound states with ordinary matter, for a similar Dark Matter candidate with not
negligible interactions, is considered. The existence of bound states, with
binding energy larger than $\sim$1 meV, would offer the possibility to test in
laboratory capture cross sections of the order of a barn (or larger). The
signature of the detection for a mass increasing of cryogenic samples, due to
the possible particle accumulation, would allow the investigation of these Dark
Matter candidates with mass up to the GUT scale. A proof of concept for a
possible detection set-up and the evaluation of some noise sources are
described.

categories: astro-ph.IM hep-ex hep-ph physics.ins-det


title: Cloud Benchmarking For Maximising Performance of Scientific Applications

abstract:
  How can applications be deployed on the cloud to achieve maximum performance?
This question is challenging to address with the availability of a wide variety
of cloud Virtual Machines (VMs) with different performance capabilities. The
research reported in this paper addresses the above question by proposing a six
step benchmarking methodology in which a user provides a set of weights that
indicate how important memory, local communication, computation and storage
related operations are to an application. The user can either provide a set of
four abstract weights or eight fine grain weights based on the knowledge of the
application. The weights along with benchmarking data collected from the cloud
are used to generate a set of two rankings - one based only on the performance
of the VMs and the other takes both performance and costs into account. The
rankings are validated on three case study applications using two validation
techniques. The case studies on a set of experimental VMs highlight that
maximum performance can be achieved by the three top ranked VMs and maximum
performance in a cost-effective manner is achieved by at least one of the top
three ranked VMs produced by the methodology.


title:
Measurement of Singly Cabibbo Suppressed Decays $\Lambda_c^{+}\to
  p\pi^{+}\pi^{-}$ and $\Lambda_c^{+}\to pK^{+}K^{-}$

abstract:
  Using 567 $pb^{-1}$ of data collected with the BESIII detector at a
center-of-mass energy of $\sqrt{s}=$ 4.599 $GeV$, near the
$\Lambda_{c}^{+}\Lambda_{c}^{-}$ threshold, we study the singly
Cabibbo-suppressed decays $\Lambda_c^{+}\to p\pi^{+}\pi^{-}$ and
$\Lambda_c^{+}\to pK^{+}K^{-}$. By normalizing with respect to the
Cabibbo-favored decay $\Lambda_c^{+}\to pK^{-}\pi^{+}$, we obtain ratios of
branching fractions: $\frac{\mathcal{B}(\Lambda_c^{+}\to
p\pi^{+}\pi^{-})}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ = $(6.70 \pm
0.48 \pm 0.25)\%$, $\frac{\mathcal{B}(\Lambda_c^{+}\to
p\phi)}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ = $(1.81 \pm 0.33 \pm
0.13)\%$, and $\frac{\mathcal{B}(\Lambda_c^{+}\to
pK^{+}K^{-}_{\text{non-}\phi})}{\mathcal{B}(\Lambda_c^{+}\to pK^{-}\pi^{+})}$ =
$(9.36 \pm 2.22 \pm 0.71)\times10^{-3}$, where the uncertainties are
statistical and systematic, respectively. The absolute branching fractions are
also presented. Among these measurements, the decay $\Lambda_c^{+}\to
p\pi^{+}\pi^{-}$ is observed for the first time, and the precision of the
branching fraction for $\Lambda_c^{+}\to pK^{+}K^{-}_{\text{non-}\phi}$ and
$\Lambda_c^{+}\to p\phi$ is significantly improved.


title: Open flavor strong decays

abstract:
  In this contribution, we discuss the results of a QM calculation of the
open-flavor strong decays of **** light nucleon resonances. These are the
results of a recent calculation, where we used a modified $^3P_0$ model for the
amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to
predict the baryon spectrum. The decay amplitudes are compared with the
existing experimental data.


title: Tunable ground states in helical $p$-wave Josephson junctions

abstract:
  We study new types of Josephson junctions composed of helical $p$-wave
superconductors with $k_{x}\hat{x}\pm k_{y}\hat{y}$ and $k_{y}\hat{x}\pm
k_{x}\hat{y}$-pairing symmetries using quasiclassical Green's functions with
the generalized Riccati parametrization. The junctions can host rich ground
states: $\pi$ phase, $0+\pi$ phase, $\varphi_{0}$ phase and $\varphi$ phase.
The phase transition can be tuned by rotating the magnetization in the
ferromagnetic interface. We present the phase diagrams in the parameter space
formed by the orientation of the magnetization or by the magnitude of the
interfacial potentials. The selection rules for the lowest order current which
are responsible for the formation of the rich phases are summarized from the
current-phase relations based on the numerical calculation. We construct a
Ginzburg-Landau type of free energy for the junctions with ${\bf{d}}$-vectors
and the magnetization, which not only reveals the interaction forms of
spin-triplet superconductivity and ferromagnetism but also can directly leads
to the selection rules. In addition, the energies of the Andreev bound states
and the novel symmetries in the current-phase relations are also investigated.
Our results are helpful both in the prediction of the novel Josephson phases
and in the design of the quantum circuits.


title:
Strong Convergence Rates for Cox-Ingersoll-Ross Processes - Full
  Parameter Range

abstract:
  We study strong (pathwise) approximation of Cox-Ingersoll-Ross processes. We
propose a Milstein-type scheme that is suitably truncated close to zero, where
the diffusion coefficient fails to be locally Lipschitz continuous. For this
scheme we prove polynomial convergence rates for the full parameter range
including the accessible boundary regime. The error criterion is given by the
maximal $L_p$-distance of the solution and its approximation on a compact
interval. In the particular case of a squared Bessel process of dimension
$\delta>0$ the polynomial convergence rate is given by $\min(1,\delta)/(2p)$.


title: Revisiting AdS/CFT at a finite radial cut-off

abstract:
  We revisit AdS/CFT at finite radial cut-off, specifically in the context of
double trace perturbations, $\mathbb{O}_n$= $\mathbb{O}(x) (\partial^2)^{n}
{\mathcal O}(x)$, with arbitrary $n$. As well-known, the standard GKPW
prescription, applied to a finite radial cut-off, leads to contact terms in
correlators. de Haro et al (arXiv:hep-th/0002230) introduced bulk counterterms
to remove these. However, this prescription yields additional terms in the
correlator corresponding to spurious double trace deformations. Further, if we
view GKPW prescription coupled with the prescription in arXiv:hep-th/0002230,
in terms of a boundary wavefunction, we find that it is incompatible with
radial Schrodinger evolution (in the spirit of holographic Wilsonian RG). We
consider a more general wavefunction satisfying the Schrodinger equation, and
find that generically such wavefunctions generate both (a) double trace
deformations and (b) contact terms. However, we find that there exist special
choices of these wavefunctions, amounting to a new AdS/CFT prescription at a
finite cut-off, so that both (a) and (b) are removed and we obtain a pure power
law behaviour for the correlator. We compare these special wavefunctions with a
specific RG scheme in field theory. We give a geometric interpretation of these
wavefunctions; these correspond to some specific smearing of boundary points in
the Witten diagrams. We present a comprehensive calculation of exact
double-trace beta-functions for all couplings $\mathbb{O}_n$ and match with a
holographic computation using the method described above. The matching works
with a mapping between the field theory and bulk couplings; such a map is
highly constrained because the beta-functions are quadratic and exact on both
sides. We generalize standard double-trace Wilson-Fisher flow to the space of
the infinite number of couplings.


title:
A Universal Construction of Universal Deformation Formulas, Drinfel'd
  Twists and their Positivity

abstract:
  In this paper we provide an explicit construction of star products on
U(g)-module algebras by using the Fedosov approach. This construction allows us
to give a constructive proof to Drinfel'd theorem and to obtain a concrete
formula for Drinfel'd twist. We prove that the equivalence classes of twists
are in one-to-one correspondence with the second Chevalley-Eilenberg cohomology
of the Lie algebra g. Finally, we show that for Lie algebras with K\"ahler
structure we obtain a strongly positive universal deformation of *-algebras by
using a Wick-type deformation. This results in a positive Drinfel'd twist.


title:
Inexact Alternating Minimization Algorithm for Distributed Optimization
  with an Application to Distributed MPC

abstract:
  In this paper, we propose the inexact alternating minimization algorithm
(inexact AMA), which allows inexact iterations in the algorithm, and its
accelerated variant, called the inexact fast alternating minimization algorithm
(inexact FAMA). We show that inexact AMA and inexact FAMA are equivalent to the
inexact proximal-gradient method and its accelerated variant applied to the
dual problem. Based on this equivalence, we derive complexity upper-bounds on
the number of iterations for the inexact algorithms. We apply inexact AMA and
inexact FAMA to distributed optimization problems, with an emphasis on
distributed MPC applications, and show the convergence properties for this
special case. By employing the complexity upper-bounds on the number of
iterations, we provide sufficient conditions on the inexact iterations for the
convergence of the algorithms. We further study the special case of quadratic
local objectives in the distributed optimization problems, which is a standard
form in distributed MPC. For this special case, we allow local computational
errors at each iteration. By exploiting a warm-starting strategy and the
sufficient conditions on the errors for convergence, we propose an approach to
certify the number of iterations for solving local problems, which guarantees
that the local computational errors satisfy the sufficient conditions and the
inexact distributed optimization algorithm converges to the optimal solution.


title:
The processes $e^{+}e^{-} \rightarrow K^{\pm} (K^{*\mp}(892),
  K^{*\mp}(1410))$ and $e^{+}e^{-} \rightarrow (\eta, \eta^{'}(958))
  (\phi(1020), \phi(1680))$ in the extended Nambu-Jona-Lasinio model

abstract:
  The processes $e^{+}e^{-} \rightarrow K^{\pm} K^{*\mp}(892)$ and $e^{+}e^{-}
\rightarrow \eta \phi(1020)$ are calculated in the framework of the extended
Nambu-Jona-Lasinio model. The intermediate vector mesons $\rho(770),
\omega(782), \phi(1020)$ and their first radially-excited states are taken into
account. The obtained results are in satisfactory agreement with the
experimental data. The predictions for the cross sections of the reactions
$e^{+}e^{-} \rightarrow K^{\pm} K^{*\mp}(1410)$, $e^{+}e^{-} \rightarrow
\eta^{'}(958) \phi(1020)$ and $e^{+}e^{-} \rightarrow \eta \phi(1680)$ were
made.


title: Isospin-violating strong decays of scalar single-heavy tetraquarks

abstract:
  We present a study of the isospin-violating one-pion strong decays of single
heavy tetraquarks $X_Q = X(s q \bar q \bar Q)$, $Q=c, b$, and $q=u, d$ with
spin-parity $J^P = 0^+$. We assume that the tetraquarks have the configuration
of a color diquark and a antidiquark. Three mechanisms of isospin violation can
contribute to the decay rate: (1) mixing of the $X(s u \bar u \bar Q)$ and $X(s
d \bar d \bar Q)$ tetraquark currents, (2) an explicit $m_d-m_u$ quark mass
difference in the quark diagrams describing the corresponding decay transitions
and (3) $\pi^0-\eta$ mixing in the final state. Our main results are: (1) It is
quite likely that the investigated tetraquark states are isosinglet states with
a small admixture of an isotriplet component; (2) The first isospin-breaking
mechanism affects the decay rater more significantly than the others; (3) Our
calculations contain a size parameter $\Lambda_{X_Q}$, characterizing the
distribution of the quarks in the tetraquark state $X_Q$. Absolute decay rates
depend very much on the choice of $\Lambda_{X_Q}$, varied from 1 to 2 GeV,
reflecting the compactness of the multiquark system.


title: Frequency stabilization by synchronization of Duffing oscillators

abstract:
  We present analytical and numerical results on the joint dynamics of two
coupled Duffing oscillators with nonlinearity of opposite signs (hardening and
softening). In particular, we focus on the existence and stability of
synchronized oscillations where the frequency is independent of the amplitude.
In this regime, the amplitude--frequency interdependence (a--f effect) ---a
noxious consequence of nonlinearity, which jeopardizes the use of
micromechanical oscillators in the design of time--keeping devices--- is
suppressed. By means of a multiple time scale formulation, we find approximate
conditions under which frequency stabilization is achieved, characterize the
stability of the resulting oscillations, and compare with numerical solutions
to the equations of motion.


title: Uncountable classical and quantum complexity classes

abstract:
  Polynomial--time constant--space quantum Turing machines (QTMs) and
logarithmic--space probabilistic Turing machines (PTMs) recognize uncountably
many languages with bounded error (Say and Yakary\i lmaz 2014,
arXiv:1411.7647). In this paper, we investigate more restricted cases for both
models to recognize uncountably many languages with bounded error. We show that
double logarithmic space is enough for PTMs on unary languages in sweeping
reading mode or logarithmic space for one-way head. On unary languages, for
quantum models, we obtain middle logarithmic space for counter machines. For
binary languages, arbitrary small non-constant space is enough for PTMs even
using only counter as memory. For counter machines, when restricted to
polynomial time, we can obtain the same result for linear space. For
constant--space QTMs, we follow the result for a restricted sweeping head,
known as restarting realtime.


title:
Pulse-phase control for spectral disambiguation in quantum sensing
  protocols

abstract:
  We present a method to identify spurious signals generated by finite-width
pulses in quantum sensing experiments and apply it to recently proposed
dynamical decoupling sequences for accurate spectral interpretation. We first
study the origin of these fake resonances and quantify their behavior in a
situation that involves the measurement of a classical magnetic field. Here we
show that a change of the initial phase of the sensor or, equivalently, of the
decoupling pulses leads to oscillations in the spurious signal intensity while
the real resonances remain intact. Finally we extend our results to the quantum
regime for the unambiguous detection of remote nuclear spins by utilization of
a nitrogen vacancy sensor in diamond.


title:
A New Method for Computing $\varphi$-functions and Their Condition
  Numbers of Large Sparse Matrices

abstract:
  We propose a new method for computing the $\varphi$-functions of large sparse
matrices with low rank or fast decaying singular values. The key is to reduce
the computation of $\varphi_{\ell}$-functions of a large matrix to
$\varphi_{\ell+1}$-functions of some $r$-by-$r$ matrices, where $r$ is the
numerical rank of the large matrix in question. Some error analysis on the new
method is given. Furthermore, we propose two novel strategies for estimating
2-norm condition numbers of the $\varphi$-functions. Numerical experiments
illustrate the numerical behavior of the new algorithms and show the
effectiveness of our theoretical results.


title: Nucleon tensor form factors in a relativistic confined quark model

abstract:
  We present results for the isotriplet and isosinglet tensor form factors of
the nucleon in the relativistic confined quark model. The model allows us to
calculate not only their normalizations at $Q^2=0$ and the related tensor
charges, but also the full $Q^2$-dependence. Our results are compared to
existing data and predictions of other theoretical approaches. We stress the
importance of these form factors for the phenomenology of physics beyond the
Standard Model.


title:
Missing particle associated with two bottom quarks at the LHC: Mono-$b$
  versus 2$b$ with razor variables

abstract:
  The extended Higgs sector, such as by a second Higgs doublet of type-II,
provides portals to dark sector which contains missing particles at the LHC,
e.g., dark matter (DM) particles. In this paper, working in the simplified
model and taking into consideration the wide decay width effect of the
mediator, we analyze the characteristic signatures of mono-$b$+MET and 2$b$+MET
at the LHC. The latter signature was believed to be ineffective, while we found
that, with the aid of razor shape analysis, it should be as important as the
mono-$b$ signature. In the region of relatively low mediator mass (below a few
hundred GeV), by requiring the signal to background ratio greater than a few
percent, the 2$b$-tagged razor analysis has comparable sensitivity to the
mono-$b$ search; it is even better for mediator lighter than $\sim 200$ GeV.


title:
A Derivation of the Vlasov-Navier-Stokes Model for Aerosol Flows from
  Kinetic Theory

abstract:
  This article proposes a derivation of the Vlasov-Navier-Stokes system for
spray/aerosol flows. The distribution function of the dispersed phase is
governed by a Vlasov-equation, while the velocity field of the propellant
satisfies the Navier-Stokes equations for incompressible fluids. The dynamics
of the dispersed phase and of the propellant are coupled through the drag force
exerted by the propellant on the dispersed phase. We present a formal
derivation of this model from a multiphase Boltzmann system for a binary
gaseous mixture, involving the droplets/dust particles in the dispersed phase
as one species, and the gas molecules as the other species. Under suitable
assumptions on the collision kernels, we prove that the sequences of solutions
to the multiphase Boltzmann system converge to distributional solutions to the
Vlasov-Navier-Stokes equation in some appropriate distinguished scaling limit.
Specifically, we assume (a) that the mass ratio of the gas molecules to the
dust particles/droplets is small, (b) that the thermal speed of the dust
particles/droplets is much smaller than that of the gas molecules and (c) that
the mass density of the gas and of the dispersed phase are of the same order of
magnitude.


title: Quadric bundles applied to non-maximal Higgs bundles

abstract:
  We present a survey on the moduli spaces of rank 2 quadric bundles over a
compact Riemann surface X. These are objects which generalise orthogonal
bundles and which naturally occur through the study of the connected components
of the moduli spaces of Higgs bundles over X for the real symplectic group
Sp(4,R), with non-maximal Toledo invariant. Hence they are also related with
the moduli space of representations of $\pi_1(X)$ in Sp(4,R). We explain this
motivation in some detail.


title: The heart of the Banach spaces

abstract:
  Consider an exact category in the sense of Quillen. Assume that in this
category every morphism has a kernel and that every kernel is an inflation. In
their seminal 1982 paper, Beilinson, Bernstein and Deligne consider in this
setting a t-structure on the derived category and remark that its heart can be
described as a category of formal quotients. They further point out that the
category of Banach spaces is an example, and that here a similar category of
formal quotients was studied by Waelbroeck already in 1962. In the current
article, we give a direct and rigorous construction of the latter category by
considering first the monomorphism category. Then we localize with respect to a
multiplicative system. Our approach gives rise to a heart-like category not
only for the Banach spaces. In particular, the main results apply to categories
in which the set of all kernel-cokernel pairs does not form an exact structure.
Such categories arise frequently in functional analysis.


title:
Semi-classical Dynamics of Superradiant Rayleigh Scattering in a
  Bose-Einstein Condensate

abstract:
  Due to its coherence properties and high optical depth, a Bose-Einstein
condensate provides an ideal setting to investigate collective atom-light
interactions. Superradiant light scattering in a Bose-Einstein condensate is a
fascinating example of such an interaction. It is an analogous process to Dicke
superradiance, in which an electronically inverted sample decays collectively,
leading to the emission of one or more light pulses in a well-defined
direction. Through time-resolved measurements of the superradiant light pulses
emitted by an end-pumped BEC, we study the close connection of superradiant
light scattering with Dicke superradiance. A 1D model of the system yields good
agreement with the experimental data and shows that the dynamics results from
the structures that build up in the light and matter-wave fields along the BEC.
This paves the way for exploiting the atom-photon correlations generated by the
superradiance.


title:
The $\epsilon$-capacity of a gain matrix and tolerable disturbances:
  Discrete-time perturbed linear systems

abstract:
  Discrete-time linear systems with perturbed initial state are considered. A
disturbance that infects the initial state is said to be $\epsilon$-tolerable
if the corresponding output signal is relatively insensitive to their effects.
In this paper, we will define a new set that characterize each gain matrix K
and the associated feedback control law ui=Kxi, this set will be called the
$\epsilon$-capacity of the gain matrix K. The set of all possible gain matrix
that makes the system insensitive to all disturbances is noted $\Phi\cdot$. The
characterization of $\Phi\cdot$ is investigated, and we propose an algorithmic
approach that allows to determine if a control law is belongs to $\Phi\cdot$ or
not. Numerical simulations are given.


title:
Maximum Likelihood Localization of Radiation Sources with unknown Source
  Intensity

abstract:
  In this paper, we consider a novel and robust maximum likelihood approach to
localizing radiation sources with unknown statistics of the source signal
strength. The result utilizes the smallest number of sensors required
theoretically to localize the source. It is shown, that should the source lie
in the open convex hull of the sensors, precisely $N+1$ are required in
$\mathbb{R}^N, ~N \in \{1,\cdots,3\}$. It is further shown that the region of
interest, the open convex hull of the sensors, is entirely devoid of false
stationary points. An augmented gradient ascent algorithm with random
projections should an estimate escape the convex hull is presented.


title:
Noise-Induced Polarization Switch in Single and Multiplex Complex
  Networks

abstract:
  The combination of bistability and noise is ubiquitous in complex systems,
from biological to social interactions, and has important implications for
their functioning and resilience. We analyze a simple three-state model for
bistability in networks under varying unbiased noise. In a fully connected
network increasing noise yields a collapse of bistability to an unpolarised
state. In contrast, in complex networks noise can abruptly switch the
polarization state in an irreversible way. When two networks are combined
through increasing multiplex coupling, one is dominant and progressively
imposes its state on the other, offsetting or promoting the ability of noise to
switch polarization. Our results show that dynamical correlations and asymmetry
in dynamical processes in networks are sufficient for allowing unbiased noise
to produce abrupt irreversible transitions between extremes, which can be
neutralized or enhanced by multiplex coupling.


title:
Almost split sequences for polynomial $G_r T$-modules and polynomial
  parts of Auslander-Reiten components

abstract:
  In 1996, Doty, Nakano and Peters defined infinitesimal Schur algebras,
combining the approach via polynomial representations with the approach via
$G_r T$-modules to representations of the algebraic group $G = \mathrm{GL}_n$.
We study analogues of these algebras and their Auslander-Reiten theory for
reductive algebraic groups $G$ and Borel subgroups $B$ by considering the
categories of polynomial representations of $G_r T$ and $B_r T$ as full
subcategories of $\mathrm{mod} \thinspace G_r T$ and $\mathrm{mod}\thinspace
B_r T$, respectively. We show that every component $\Theta$ of the stable
Auslander-Reiten quiver $\Gamma_s(G_r T)$ of $\mathrm{mod}\thinspace G_r T$
whose constituents have complexity 1 contains only finitely many polynomial
modules. For $G = \mathrm{GL}_2$, $r = 1$ and $T \subseteq G$ the torus of
diagonal matrices, we identify the polynomial part of the stable
Auslander-Reiten quiver of $G_r T$ and use this to determine the
Auslander-Reiten quiver of the infinitesimal Schur algebras in this situation.
For the Borel subgroup $B$ of lower triangular matrices of $\mathrm{GL}_2$, the
category of $B_r T$-modules is related to representations of elementary abelian
groups of rank $r$. In this case, we can extend our results about modules of
complexity $1$ to modules of higher Frobenius kernels arising as outer tensor
products.


title: Fractal analysis of Pi normality

abstract:
  \begin{abstract} $\pi$, the ratio between a circumference and is radius, is
an irrational transcendental number. Fractal analysis is used here to show that
$\pi$\textquoteright{s} digit sequence corresponds to a uniformly distributed
random succession of independent decimal digits, and that these properties get
clearer as the number of digits in the series grows towards infinity; $ 10^9 $
digits were tested in this work. This indicates that $ \pi $ is normal.


title: Autaptic Connections Shift Network Excitability and Bursting

abstract:
  Network architecture forms a critical constraint on neuronal function. Here
we examine the role of structural autapses, when a neuron synapses onto itself,
in driving network-wide bursting behavior. Using a simple spiking model of
neuronal activity, we study how autaptic connections affect activity patterns,
and evaluate if neuronal degree or controllability are significant factors that
affect changes in bursting from these autaptic connections. We observed that
adding increasing numbers of autaptic connections to excitatory neurons
increased the number of spiking events in the network and the number of
network-wide bursts, particularly in the portion of the phase space in which
excitatory synapses were stronger contributors to bursting behavior than
inhibitory synapses. In comparison, autaptic connections to excitatory neurons
with high average controllability led to higher burst frequencies than adding
the same number of self-looping connections to neurons with high modal
controllability. The number of autaptic connections required to induce bursting
behavior could be lowered by selectively adding autapses to high degree
excitatory neurons. These results suggest a role of autaptic connections in
controlling network-wide bursts in diverse cortical and subcortical regions of
mammalian brain. Moreover, they open up new avenues for the study of dynamic
neurophysiological correlates of structural controllability.


title: Low lying spectral gaps induced by slowly varying magnetic fields

abstract:
  We consider a periodic Schr\"odinger operator in two dimensions perturbed by
a weak magnetic field whose intensity slowly varies around a positive mean. We
show in great generality that the bottom of the spectrum of the corresponding
magnetic Schr\"odinger operator develops spectral islands separated by gaps,
reminding of a Landau-level structure.
  First, we construct an effective Hofstadter-like magnetic matrix which
accurately describes the low lying spectrum of the full operator. The
construction of this effective magnetic matrix does not require a gap in the
spectrum of the non-magnetic operator, only that the first and the second Bloch
eigenvalues do not cross but their ranges might overlap. The crossing case is
more difficult and will be considered elsewhere.
  Second, we perform a detailed spectral analysis of the effective matrix using
a gauge-covariant magnetic pseudo-differential calculus adapted to slowly
varying magnetic fields. As an application, we prove in the overlapping case
the appearance of spectral islands separated by gaps.


title: Example Data Sets and Collections for BeSpaceD Explained

abstract:
  In this report, we present example data sets and collections for the BeSpaceD
platform. BeSpaceD is a spatio-temporal modelling and reasoning software
framework. We describe the content of a number of the data sets and how the
data was obtained. We also present the programming API in BeSpaceD used to
store and access these data sets so that future BeSpaceD users can utilise the
data collections in their own experiments with minimal effort and expand the
library of data collections for BeSpaceD.


title: Experimental Quantum Multiparty Communication Protocols

abstract:
  Quantum information science breaks limitations of conventional information
transfer, cryptography and computation by using quantum superpositions or
entanglement as resources for information processing. Here, we report on the
experimental realization of three-party quantum communication protocols using
single three-level quantum system (qutrit) communication: secret sharing,
detectable Byzantine agreement, and communication complexity reduction for a
three-valued function. We have implemented these three schemes using the same
optical fiber interferometric setup. Our realization is easily scalable without
sacrificing detection efficiency or generating extremely complex many-particle
entangled states.


title: Search for structure in the $B_s^0\pi^\pm$ invariant mass spectrum

abstract:
  The $B_s^0\pi^\pm$ invariant mass distribution is investigated in order to
search for possible exotic meson states. The analysis is based on a data sample
recorded with the LHCb detector corresponding to $3$ fb$^{-1}$ of $pp$
collision data at $\sqrt{s} = 7$ and $8$ TeV. No significant excess is found,
and upper limits are set on the production rate of the claimed $X(5568)$ state
within the LHCb acceptance. Upper limits are also set as a function of the mass
and width of a possible exotic meson decaying to the $B_s^0\pi^\pm$ final
state. The same limits also apply to a possible exotic meson decaying through
the chain $B_s^{*0}\pi^\pm$, $B_s^{*0} \to B_s^0 \gamma$ where the photon is
excluded from the reconstructed decays.