title: Primordial black holes from supersymmetry in the early universe

abstract:
  Supersymmetric extensions of the standard model generically predict that in
the early universe a scalar condensate can form and fragment into Q-balls
before decaying. If the Q-balls dominate the energy density for some period of
time, the relatively large fluctuations in their number density can lead to
formation of primordial black holes (PBH). Other scalar fields, unrelated to
supersymmetry, can play a similar role. For a general charged scalar field,
this robust mechanism can generate black holes over the entire mass range
allowed by observational constraints, with a sufficient abundance to account
for all dark matter in some parameter ranges. In the case of supersymmetry the
mass range is limited from above by $10^{23}$g. We also comment on the role
that topological defects can play for PBH formation in a similar fashion.


title:
Accurate and Versatile High-Order Modeling of Electromagnetic Scattering
  on Plasmonic Nanostructures

abstract:
  This paper presents high-order (HO) electromagnetic modeling of plasmonic
nanostructures based on the Locally Corrected Nystrom (LCN) method. Advanced
nanophotonic and nanoplasmonic structures involve electrically large
electromagnetic structures that are very complex in both geometry and material
composition. Hence, advanced analysis and design tools are required in order to
predict the performance of such structures and optimize the geometrical
parameters prior to costly prototype development. In this perspective, the LCN
is exploited to solve the electromagnetic scattering of plasmonic
nanostructures. The LCN utilizes basis functions of higher orders defined on
large geometrical elements, which significantly reduces the number of unknowns
for a given problem. Compared to other well-known methods for EM modeling of
plasmonic nanostructures, the LCN is computationally efficient, straightforward
to implement and provides exponential convergence. A full comparison, in terms
of time and complexity between the proposed method and previous works for a few
3D nanoplasmonic structures are presented to validate the accuracy, efficiency
and flexibility of the proposed method to simulate the behavior of
electromagnetic fields in real nanoplasmonic problems.


title:
A Note on Logarithmic Space Stream Algorithms for Matchings in Low
  Arboricity Graphs

abstract:
  We present a data stream algorithm for estimating the size of the maximum
matching of a low arboricity graph. Recall that a graph has arboricity $\alpha$
if its edges can be partitioned into at most $\alpha$ forests and that a planar
graph has arboricity $\alpha=3$. Estimating the size of the maximum matching in
such graphs has been a focus of recent data stream research.
  A surprising result on this problem was recently proved by Cormode et al.
They designed an ingenious algorithm that returned a
$(22.5\alpha+6)(1+\epsilon)$ approximation using a single pass over the edges
of the graph (ordered arbitrarily) and $O(\epsilon^{-2}\alpha \cdot \log n
\cdot \log_{1+\epsilon} n)$ space. In this note, we improve the approximation
factor to $(\alpha+2)(1+\epsilon)$ via a tighter analysis and show that, with a
modification of their algorithm, the space required can be reduced to
$O(\epsilon^{-2} \log n)$.


title:
Galactic Shapiro Delay to the Crab Pulsar and limit on Einstein's
  Equivalence Principle Violation

abstract:
  We calculate the total galactic Shapiro delay to the Crab pulsar by including
the contributions from the dark matter as well as baryonic matter along the
line of sight. The total delay due to dark matter potential is about 3.4 days.
For baryonic matter, we included the contributions from both the bulge and the
disk, which are approximately 0.12 and 0.32 days respectively. The total delay
from all the matter distribution is therefore 3.84 days. We also calculate the
limit on violations of Einstein's equivalence principle by using observations
of "nano-shot" giant pulses from the Crab pulsar with time-delay $<0.4$~ns as
well as using time differences between radio and optical photons observed from
this pulsar. Using the former, we obtain a limit on violation of Einstein's
equivalence principle in terms of the PPN parameter $\Delta \gamma < 2.41\times
10^{-15}$. From the time-difference between simultaneous optical and radio
observations, we get $\Delta \gamma < 1.54\times 10^{-9}$. We also point out
differences in our calculation of Shapiro delay and that from two recent papers
(arXiv:1612.00717 and arXiv:1608.07657), which used the same observations to
obtain a corresponding limit on $\Delta \gamma$.


title:
Tunable narrow-band plasmonic resonances in
  electromagnetically-induced-transparency media

abstract:
  The spectral response of a plasmonic nanostructure may heavily depend on the
refractive index of its surroundings. The key idea of this paper is to control
this response by coherent optical means, i.e. with an optically controlled
electromagnetically-induced-transparency medium. In such environment, an
external laser provides a knob to shift the position of plasmonic resonances
without the need to change the geometry of the nanostructure. Additionally, the
setup can be exploited to excite narrow-band surface plasmon polaritons.


title: Contextual Visual Similarity

abstract:
  Measuring visual similarity is critical for image understanding. But what
makes two images similar? Most existing work on visual similarity assumes that
images are similar because they contain the same object instance or category.
However, the reason why images are similar is much more complex. For example,
from the perspective of category, a black dog image is similar to a white dog
image. However, in terms of color, a black dog image is more similar to a black
horse image than the white dog image. This example serves to illustrate that
visual similarity is ambiguous but can be made precise when given an explicit
contextual perspective. Based on this observation, we propose the concept of
contextual visual similarity. To be concrete, we examine the concept of
contextual visual similarity in the application domain of image search. Instead
of providing only a single image for image similarity search (\eg, Google image
search), we require three images. Given a query image, a second positive image
and a third negative image, dissimilar to the first two images, we define a
contextualized similarity search criteria. In particular, we learn feature
weights over all the feature dimensions of each image such that the distance
between the query image and the positive image is small and their distances to
the negative image are large after reweighting their features. The learned
feature weights encode the contextualized visual similarity specified by the
user and can be used for attribute specific image search. We also show the
usefulness of our contextualized similarity weighting scheme for different
tasks, such as answering visual analogy questions and unsupervised attribute
discovery.


title:
A Hot Companion to a Blue Straggler in NGC188 as Revealed by the
  Ultra-violet Imaging Telescope (UVIT) on ASTROSAT

abstract:
  We present early results from the Ultra-Violet Imaging Telescope (UVIT)
onboard the ASTROSAT observatory. We report the discovery of a hot companion
associated with one of the blue straggler stars (BSSs) in the old open cluster,
NGC188. Using fluxes measured in four filters in UVIT's Far-UV (FUV) channel,
and two filters in the near-UV (NUV) channel, we have constructed the spectral
energy distribution (SED) of the star WOCS-5885, after combining with flux
measurements from GALEX, UIT, UVOT, SPITZER, WISE and several ground-based
facilities. The resulting SED spans a wavelength range of 0.15~${\mu}$m to
7.8~${\mu}$m. This object is found to be one of the brightest FUV sources in
the cluster. An analysis of the SED reveals the presence of two components. The
cooler component is found to have a temperature of 6,000$\pm$150~K, confirming
that it is a BSS. Assuming it to be a main-sequence star, we estimate its mass
to be $\sim$ 1.1 - 1.2M$_\odot$. The hotter component, with an estimated
temperature of 17,000$\pm$500~K, has a radius of $\sim$ 0.6R$_\odot$ and L
$\sim$ 30L$_\odot$. Bigger and more luminous than a white dwarf, yet cooler
than a sub-dwarf, we speculate that it is a post-AGB/HB star that has recently
transferred its mass to the BSS, which is known to be a rapid rotator. This
binary system, which is the first BSS with a post-AGB/HB companion identified
in an open cluster, is an ideal laboratory to study the process of BSS
formation via mass transfer.


title: Approximate Likelihood Construction for Rough Differential Equations

abstract:
  The paper is split in two parts: in the first part, we construct the exact
likelihood for a discretely observed rough differential equation, driven by a
piecewise linear path. In the second part, we use this likelihood in order to
construct an approximation of the likelihood for a discretely observed
differential equation driven by a general class of rough paths. Finally, we
study the behaviour of the approximate likelihood when the sampling frequency
tends to infinity.


title: Another phase transition in the Axelrod model

abstract:
  Axelrod's model of cultural dissemination, despite its apparent simplicity,
demonstrates complex behavior that has been of much interest in statistical
physics. Despite the many variations and extensions of the model that have been
investigated, a systematic investigation of the effects of changing the size of
the neighborhood on the lattice in which interactions can occur has not been
made. Here we investigate the effect of varying the radius R of the von Neumann
neighborhood in which agents can interact. We show, in addition to the
well-known phase transition at the critical value of q, the number of traits,
another phase transition at a critical value of R, and draw a q -- R phase
diagram for the Axelrod model on a square lattice. In addition, we present a
mean-field approximation of the model in which behavior on an infinite lattice
can be analyzed.


title: $L^0$-regularized Variational Methods for Sparse Phase Retrieval

abstract:
  We study the problem of recovering the underlining sparse signals from clean
or noisy phaseless measurements. Due to the sparse prior of signals, we adopt
an L0regularized variational model to ensure only a small number of nonzero
elements being recovered in the signal and two different formulations are
established in the modeling based on the choices of data fidelity, i.e., L2and
L1norms. We also propose efficient algorithms based on the Alternating
Direction Method of Multipliers (ADMM) with convergence guarantee and nearly
optimal computational complexity. Thanks to the existence of closed-form
solutions to all subproblems, the proposed algorithm is very efficient with low
computational cost in each iteration. Numerous experiments show that our
proposed methods can recover sparse signals from phaseless measurements with
higher successful recovery rates and lower computation cost compared with the
state-of-art methods.


title:
Entanglement and coherence in a spin-s XXZ system under non-uniform
  fields

abstract:
  We investigate entanglement and coherence in an $XXZ$ spin-$s$ pair immersed
in a non-uniform transverse magnetic field. The ground state and thermal
entanglement phase diagrams are analyzed in detail in both the ferromagnetic
and antiferromagnetic cases. It is shown that a non-uniform field enables to
control the energy levels and the entanglement of the corresponding
eigenstates, making it possible to entangle the system for any value of the
exchange couplings, both at zero and finite temperatures. Moreover, the limit
temperature for entanglement is shown to depend only on the difference
$|h_1-h_2|$ between the fields applied at each spin, leading for $T>0$ to a
separability stripe in the $(h_1,h_2)$ field plane such that the system becomes
entangled above a threshold value of $|h_1-h_2|$. These results are
demonstrated to be rigorously valid for any spin $s$. On the other hand, the
relative entropy of coherence in the standard basis, which coincides with the
ground state entanglement entropy at $T=0$ for any $s$, becomes non-zero for
any value of the fields at $T>0$, decreasing uniformly for sufficiently high
$T$. A special critical point arising at $T=0$ for non-uniform fields in the
ferromagnetic case is also discussed


title:
City traffic forecasting using taxi GPS data: A coarse-grained cellular
  automata model

abstract:
  City traffic is a dynamic system of enormous complexity. Modeling and
predicting city traffic flow remains to be a challenge task and the main
difficulties are how to specify the supply and demands and how to parameterize
the model. In this paper we attempt to solve these problems with the help of
large amount of floating car data. We propose a coarse-grained cellular
automata model that simulates vehicles moving on uniform grids whose size are
much larger compared with the microscopic cellular automata model. The car-car
interaction in the microscopic model is replaced by the coupling between
vehicles and coarse-grained state variables in our model. To parameterize the
model, flux-occupancy relations are fitted from the historical data at every
grids, which serve as the coarse-grained fundamental diagrams coupling the
occupancy and speed. To evaluate the model, we feed it with the historical
travel demands and trajectories obtained from the floating car data and use the
model to predict road speed one hour into the future. Numerical results show
that our model can capture the traffic flow pattern of the entire city and make
reasonable predictions. The current work can be considered a prototype for a
model-based forecasting system for city traffic.


title: Query-adaptive Image Retrieval by Deep Weighted Hashing

abstract:
  Hashing methods have attracted much attention for large scale image
retrieval. Some deep hashing methods have achieved promising results by taking
advantage of the strong representation power of deep networks recently.
However, existing deep hashing methods treat all hash bits equally. On one
hand, a large number of images share the same distance to a query image due to
the discrete Hamming distance, which raises a critical issue of image retrieval
where fine-grained rankings are very important. On the other hand, different
hash bits actually contribute to the image retrieval differently, and treating
them equally greatly affects the retrieval accuracy of image. To address the
above two problems, we propose the query-adaptive deep weighted hashing (QaDWH)
approach, which can perform fine-grained ranking for different queries by
weighted Hamming distance. First, a novel deep hashing network is proposed to
learn the hash codes and corresponding class-wise weights jointly, so that the
learned weights can reflect the importance of different hash bits for different
image classes. Second, a query-adaptive image retrieval method is proposed,
which rapidly generates hash bit weights for different query images by fusing
its semantic probability and the learned class-wise weights. Fine-grained image
retrieval is then performed by the weighted Hamming distance, which can provide
more accurate ranking than the traditional Hamming distance. Experiments on
four widely used datasets show that the proposed approach outperforms eight
state-of-the-art hashing methods.


title: Minimum Rates of Approximate Sufficient Statistics

abstract:
  Given a sufficient statistic for a parametric family of distributions, one
can estimate the parameter without access to the data. However, the memory or
code size for storing the sufficient statistic may nonetheless still be
prohibitive. Indeed, for $n$ independent samples drawn from a $k$-nomial
distribution with $d=k-1$ degrees of freedom, the length of the code scales as
$d\log n+O(1)$. In many applications, we may not have a useful notion of
sufficient statistics (e.g., when the parametric family is not an exponential
family) and we also may not need to reconstruct the generating distribution
exactly. By adopting a Shannon-theoretic approach in which we allow a small
error in estimating the generating distribution, we construct various {\em
approximate sufficient statistics} and show that the code length can be reduced
to $\frac{d}{2}\log n+O(1)$. We consider errors measured according to the
relative entropy and variational distance criteria. For the code constructions,
we leverage Rissanen's minimum description length principle, which yields a
non-vanishing error measured according to the relative entropy. For the
converse parts, we use Clarke and Barron's formula for the relative entropy of
a parametrized distribution and the corresponding mixture distribution.
However, this method only yields a weak converse for the variational distance.
We develop new techniques to achieve vanishing errors and we also prove strong
converses. The latter means that even if the code is allowed to have a
non-vanishing error, its length must still be at least $\frac{d}{2}\log n$.


title: Study of the rare decays $B_{s,d}^* \to \mu^+ \mu^-$

abstract:
  We investigate the effect of scalar leptoquarks and family non-universal
$Z^\prime$ boson on the rare leptonic decays of $B_{s, d}^*$ mesons, mediated
by the FCNC transitions $b \to (d, s) l^+ l^-$. They are sensitive to a variety
of new physics operators as opposed to the $B_{s,d}$ leptonic modes and hence,
can provide an ideal testing ground to look for new physics beyond the standard
model. We work out the constraint on new physics parameter space using the
measured branching ratios of $B_{d, s} \to \mu^+ \mu^-$ processes and the $B_q
- \bar B_q$ mixing data. Using the constrained parameters we estimate the
branching ratios of $B_{d,s} \to \mu^+ \mu^-~(e^+ e^-)$ processes. We find that
the branching ratios are reasonably enhanced from their corresponding standard
model values in the $X(3,2,1/6)$ leptoquark model and are expected to be within
the reach of Run II/III of LHC experiments.


title:
Starspots, Stellar Cycles and Stellar Flares: Lessons from Solar Dynamo
  Models

abstract:
  In this review, we discuss whether the present solar dynamo models can be
extrapolated to explain various aspects of stellar activity. We begin with a
summary of the following kinds of data for solar-like stars: (i) data
pertaining to stellar cycles from Ca H/K emission over many years; (ii) X-ray
data indicating hot coronal activity; (iii) starspot data (especially about
giant polar spots); and (iv) data pertaining to stellar superflares. Then we
describe the current status of solar dynamo modelling---giving an introduction
to the flux transport dynamo model, the currently favoured model for the solar
cycle. While an extrapolation of this model to solar-like stars can explain
some aspects of observational data, some other aspects of the data still remain
to be theoretically explained. It is not clear right now whether we need a
different kind of dynamo mechanism for stars having giant starspots or
producing very strong superflares.


title:
A Constituent Codes Oriented Code Construction Scheme for Polar Code-Aim
  to Reduce the Decoding Latency

abstract:
  This paper proposes a polar code construction scheme that reduces
constituent-code supplemented decoding latency. Constituent codes are the
sub-codewords with specific patterns. They are used to accelerate the
successive cancellation decoding process of polar code without any performance
degradation. We modify the traditional construction approach to yield increased
number of desirable constituent codes that speeds the decoding process. For
(n,k) polar code, instead of directly setting the k best and (n-k) worst bits
to the information bits and frozen bits, respectively, we swap the locations of
some information and frozen bits carefully according to the qualities of their
equivalent channels. We conducted the simulation of 1024 and 2048 bits length
polar codes with multiple rates and analyzed the decoding latency for various
length codes. The numerical results show that the proposed construction scheme
generally is able to achieve at least around 20% latency deduction with an
negligible loss in gain with carefully selected optimization threshold.


title: Finite nuclei in the reggeon "toy" model

abstract:
  Hadron-nucleus amplitudes at high energies are studied in the "toy" Regge
model in zero transverse dimension for finite nuclei, when the standard series
of fan diagrams is converted into a finite sum and looses physical sense at
quite low energies. Taking into account all the loop contributions by numerical
methods we find a physically meaningful amplitudes at all energies. They
practically coincide with the amplitudes for infinite nuclei. A surprizing
result is that for finite nuclei and small enough triple pomeron coupling the
infinite series of fan diagrams describes the amplitude quite well in spite of
the fact that in reality the series should be cut and as such deprived of any
physical sense at high energies.


title: Self-composable Programming

abstract:
  Many variability management techniques rely on sophisticated language
extension or tools to support it. While this can provide dedicated syntax and
operational mechanism but it struggling practical adaptation for the cost of
adapting new technology as part of development process. We present
Self-composable Programming, a language-driven, composition-based variability
implementation which takes an object-oriented approach to modeling and
composing behaviors in software. Self-composable Programming introduces
hierarchical relationship of behavior by providing concepts of abstract
function, which modularise commonalities, and specific function which inherits
from abstract function and be apply refinement to contain variabilities to
fulfill desired functionality. Various object-oriented techniques can
applicable in the refinement process including explicit method-based, and
implicit traits-based refinement. In order to evaluate the potential
independence of behavior from the object by applying object-orientation to
function, we compare it to Aspect-oriented Programming both conceptually and
empirically.


title:
Overall momentum balance and redistribution of the lost energy in
  asymmetric dijet events in 2.76~ATeV Pb-Pb collisions with a multi-phase
  transport model

abstract:
  The overall transverse momentum balance and the redistribution of the lost
energy from hard jets for asymmetric dijet events in PbPb collisions at
2.76~ATeV at the LHC is studied within A Multi-Phase Transport (AMPT) model. A
detailed analysis is performed for the projected transverse momentum $\langle
\slashed{p}_{T}^{||} \rangle$ contributed from the final charged hadrons
carrying different transverse momenta and emitted from different angular
directions. We find that the transverse momentum projection $\langle
\slashed{p}_{T}^{||} \rangle $ in the leading jet direction is mainly
contributed by hard hadrons ($p_T > 8.0$~GeV/$c$) in both peripheral and
central PbPb collisions, while the opposite direction in central collisions is
dominated by soft hadrons ($p_T = 0.5$-$2.0$~GeV/$c$). The study of in-cone and
out-of-cone contributions to $\langle \slashed{p}_{T}^{||} \rangle$ shows that
these soft hadrons are mostly emitted at large angles away from the dijet axis.
Our AMPT calculation is in qualitative agreement with the CMS measurements and
the primary mechanism for the energy transported to large angles in the AMPT
model is the elastic scattering at the partonic stage. Future studies including
also inelastic processes should be helpful in understanding the overestimation
of the magnitudes of in-cone and out-of-cone imbalances from our AMPT
calculations, and shed light on different roles played by radiative and
collisional processes in the redistribution of the lost energy from hard jets.


title:
On Constructivity and the Rosser Property: a closer look at some
  G\"odelean proofs

abstract:
  The proofs of Kleene, Chaitin and Boolos for G\"odel's First Incompleteness
Theorem are studied from the perspectives of constructivity and the Rosser
property. A proof of the incompleteness theorem has the Rosser property when
the independence of the true but unprovable sentence can be shown by assuming
only the (simple) consistency of the theory. It is known that G\"odel's own
proof for his incompleteness theorem does not have the Rosser property, and we
show that neither do Kleene's or Boolos' proofs. However, we show that a
variant of Chaitin's proof can have the Rosser property. The proofs of G\"odel,
Rosser and Kleene are constructive in the sense that they explicitly construct,
by algorithmic ways, the independent sentence(s) from the theory. We show that
the proofs of Chaitin and Boolos are not constructive, and they prove only the
mere existence of the independent sentences.


title: Quark Mass Matrices, textures and CKM precision measurements

abstract:
  In the light of several recent analyses pointing towards texture 4-zero
Fritzsch-like quark mass matrices as the only viable structures for quark mass
matrices, this work adopts a model independent approach to reconstruct an
alternate and simplified structure of texture specific quark mass matrices in a
generalized 'u-diagonal' basis within the Standard Model framework using the
Unitarity of CKM matrix and the observed hierarchies in quark mass spectra and
mixing angles. It is observed that the measured 1$\sigma$ values of the three
physical parameters namely $m_{\rm{u}}$, $m_{\rm{d}}$ and $s_{12}$ naturally
lead to the vanishing of (11) element in the down type quark mass matrix and
that the single measurable CP violating phase $\delta_{13}$ in the CKM matrix
is sufficient enough in $M^{\prime}_{\rm{d}}$ to explain the observed mixing
pattern in a suitable basis. The leading order as well as exact analytic
phenomenological solutions are addressed for the modest pattern of quark mass
matrices derived from CKM matrix and precision measurements of mixing
parameters.


title:
The golden age of Calcutta physics: Difficulties in reconstructing the
  history

abstract:
  Classes started in the newly established Physics Department of Calcutta
University Science College in 1916. Raman, Bose and Saha were three young
members of the small physics faculty consisting of barely half a dozen faculty
members. Within about one decade, three extraordinary discoveries came from
these young men---Saha ionization equation in 1920, Bose statistics in 1924,
Raman effect in 1928. However, fortunes of Calcutta University quickly got
intertwined with India's freedom struggle led by Mahatma Gandhi exactly at the
same time and the physics group got tragically disrupted. Indian physics never
succeeded in reaching that height again. This paper discusses the difficulties
in reconstructing a critical history of this Calcutta school of physics during
the very short epoch of unmatched brilliance.

categories: physics.hist-ph physics.ed-ph physics.pop-ph quant-ph


title:
Recovering Quantum Information in Orbital Angular Momentum of Photons by
  Adaptive Optics

abstract:
  Orbital angular momentum of photons is an intriguing system for the storage
and transmission of quantum information, but it is rapidly degraded by
atmospheric turbulence. We explore the ability of adaptive optics to compensate
for this disturbance by measuring and correcting cumulative phase shifts in the
wavefront. These shifts can be represented as a sum of Zernike functions; we
analyze the residual errors after correcting up to a certain number of Zernike
modes when an orbital angular momentum state is transmitted through a turbulent
atmosphere whose density fluctuations have a Kolmogorov spectrum. We
approximate the superoperator map that represents these residual errors and
find the solution in closed form. We illustrate with numerical examples how
this perturbation depends on the the number of Zernike modes corrected and the
orbital angular momentum state of the light.


title: Optical Vortex Beam Propagation in Turbulent Atmosphere

abstract:
  Propagation of optical vortex beamlet (OVB) in turbulent atmospheric
environment is studied theoretically by normalized models. Our simulation shows
that optical vortex beamlet is superior to traditional Gaussian beam in terms
of diffraction behavior of long haul propagation. Formation of vortex beam let
is experimentally demonstrated by using a spatial light modulator (SLM), which
achieve a power efficiency of more than 90% when the intrinsic loss in SLM is
excluded.


title: MultiView High Precision VLBI Astrometry at Low Frequencies

abstract:
  The arrival of the Square Kilometer Array (SKA) will revitalise all aspects
of Very Long Baseline Interferometry (VLBI) astronomy at the lower frequencies.
In the last decade there have been huge strides towards routinely achieving
high precision VLBI astrometry at frequencies dominated by the tropospheric
contributions, most notably at 22GHz, using advanced phase referencing
techniques. Nevertheless to increase the capability for high precision
astrometric measurements at low radio frequencies (<8GHz) an effective
calibration strategy of the systematic ionospheric propagation effects that is
widely applicable is required. Observations at low frequencies are dominated by
distinct direction dependent ionospheric propagation errors, which place a very
tight limit on the angular separation of a suitable phase referencing
calibrator.
  The MultiView technique holds the key to the compensation of atmospheric
spatial-structure errors, by using observations of multiple calibrators and 2-D
interpolation. In this paper we present the first demonstration of the power of
MultiView using three calibrators, several degrees from the target, along with
a comparative study of the astrometric accuracy between MultiView and
phase-referencing techniques.
  MultiView calibration provides an order of magnitude improvement in
astrometry with respect to conventional phase referencing, achieving ca. 100
micro-arcseconds astrometry errors in a single epoch of observations,
effectively reaching the thermal noise limit.
  MultiView will achieve its full potential with the enhanced sensitivity and
multibeam capabilities of SKA and the pathfinders, which will enable
simultaneous observations of the target and calibrators. Our demonstration
indicates that the 10 micro-arcseconds goal of astrometry at ~1.6GHz using VLBI
with SKA is feasible using the MultiView technique.


title: Charge transfer in ultracold gases via Feshbach resonances

abstract:
  We investigate the prospects of controlling charge-exchange in ultracold
collisions of heteroisotopic combinations of atoms and ions of the same
element. The treatment, readily applicable to alkali or alkanine-earth metals,
is illustrated in the process $^9$Be$^{+}$ + $^{10}$Be $\leftrightarrow$
$^{9}$Be + $^{10}$Be$^{+}$, which exhibits favorable electronic, nuclear, and
hyperfine structure. Feshbach resonances are obtained from quantum scattering
calculations in a standard coupled-channel formalism with non-BO terms
originating from the nuclear kinetic operator. Near a narrow resonance
predicted at 322 G, we find the charge-exchange rate coefficient to rise from
practically zero to values larger than $10^{-12}$ cm$^3$/s. Our results suggest
controllable charge-exchange reactions between different isotopes of suitable
atom-ion pairs with potential applications to quantum systems engineered to
study charge diffusion in trapped cold atom-ion mixtures and emulate many-body
physics.


title: The Two Rigid Body Interaction using Angular Momentum Theory Formulae

abstract:
  This work presents an elegant formalism to model the evolution of the full
two rigid body problem. The equations of motion, given in a Cartesian
coordinate system, are expressed in terms of spherical harmonics and Wigner
D-matrices. The algorithm benefits from the numerous recurrence relations
satisfied by these functions allowing a fast evaluation of the mutual
potential. Moreover, forces and torques are straightforwardly obtained by
application of ladder operators taken from the angular momentum theory and
commonly used in quantum mechanics. A numerical implementation of this
algorithm is made. Tests show that the present code is significantly faster
than those currently available in literature.


title:
Sorting Data on Ultra-Large Scale with RADULS. New Incarnation of Radix
  Sort

abstract:
  The paper introduces RADULS, a new parallel sorter based on radix sort
algorithm, intended to organize ultra-large data sets efficiently. For example
4G 16-byte records can be sorted with 16 threads in less than 15 seconds on
Intel Xeon-based workstation. The implementation of RADULS is not only highly
optimized to gain such an excellent performance, but also parallelized in a
cache friendly manner to make the most of modern multicore architectures.
Besides, our parallel scheduler launches a few different procedures at runtime,
according to the current parameters of the execution, for proper workload
management. All experiments show RADULS to be superior to competing algorithms.


title:
Complete spin and orbital evolution of close-in bodies using a Maxwell
  viscoelastic rheology

abstract:
  In this paper, we present a formalism designed to model tidal interaction
with a viscoelastic body made of Maxwell material. Our approach remains regular
for any spin rate and orientation, and for any orbital configuration including
high eccentricities and close encounters. The method is to integrate
simultaneously the rotation and the position of the planet as well as its
deformation. We provide the equations of motion both in the body frame and in
the inertial frame. With this study, we generalize preexisting models to the
spatial case and to arbitrary multipole orders using a formalism taken from
quantum theory. We also provide the vectorial expression of the secular tidal
torque expanded in Fourier series. Applying this model to close-in exoplanets,
we observe that if the relaxation time is longer than the revolution period,
the phase space of the system is characterized by the presence of several
spin-orbit resonances, even in the circular case. As the system evolves, the
planet spin can visit different spin-orbit configurations. The obliquity is
decreasing along most of these resonances, but we observe a case where the
planet tilt is instead growing. These conclusions derived from the secular
torque are successfully tested with numerical integrations of the instantaneous
equations of motion on HD 80606b. Our formalism is also well adapted to
close-in super-Earths in multiplanet systems which are known to have non-zero
mutual inclinations.


title: AGA: Attribute Guided Augmentation

abstract:
  We consider the problem of data augmentation, i.e., generating artificial
samples to extend a given corpus of training data. Specifically, we propose
attributed-guided augmentation (AGA) which learns a mapping that allows to
synthesize data such that an attribute of a synthesized sample is at a desired
value or strength. This is particularly interesting in situations where little
data with no attribute annotation is available for learning, but we have access
to a large external corpus of heavily annotated samples. While prior works
primarily augment in the space of images, we propose to perform augmentation in
feature space instead. We implement our approach as a deep encoder-decoder
architecture that learns the synthesis function in an end-to-end manner. We
demonstrate the utility of our approach on the problems of (1) one-shot object
recognition in a transfer-learning setting where we have no prior knowledge of
the new classes, as well as (2) object-based one-shot scene recognition. As
external data, we leverage 3D depth and pose information from the SUN RGB-D
dataset. Our experiments show that attribute-guided augmentation of high-level
CNN features considerably improves one-shot recognition performance on both
problems.


title: Detection of a pair of prominent X-ray cavities in Abell 3847

abstract:
  We present results obtained from a detailed analysis of a deep Chandra
observation of the bright FR II radio galaxy 3C~444 in Abell~3847 cluster. A
pair of huge X-ray cavities are detected along North and South directions from
the centre of 3C 444. X-ray and radio images of the cluster reveal peculiar
positioning of the cavities and radio bubbles. The radio lobes and X-ray
cavities are apparently not spatially coincident and exhibit offsets by ~61 kpc
and ~77 kpc from each other along the North and South directions, respectively.
Radial temperature and density profiles reveal the presence of a cool core in
the cluster. Imaging and spectral studies showed the removal of substantial
amount of matter from the core of the cluster by the radio jets. A detailed
analysis of the temperature and density profiles showed the presence of a
rarely detected elliptical shock in the cluster. Detection of inflating
cavities at an average distance of ~55 kpc from the centre implies that the
central engine feeds a remarkable amount of radio power (~6.3 X 10^44 erg/s)
into the intra-cluster medium over ~10^8 yr, the estimated age of cavity. The
cooling luminosity of the cluster was estimated to be ~8.30 X 10^43 erg/s,
which confirms that the AGN power is sufficient to quench the cooling. Ratios
of mass accretion rate to Eddington and Bondi rates were estimated to be ~0.08
and 3.5 X 10^4, respectively. This indicates that the black hole in the core of
the cluster accretes matter through chaotic cold accretion.


title:
A Higher Order Isoparametric Fictitious Domain Method for Level Set
  Domains

abstract:
  We consider a new fictitious domain approach of higher order accuracy. To
implement Dirichlet conditions we apply the classical Nitsche method combined
with a facet-based stabilization (ghost penalty). Both techniques are combined
with a higher order isoparametric finite element space which is based on a
special mesh transformation. The mesh transformation is build upon a higher
order accurate level set representation and allows to reduce the problem of
numerical integration to problems on domains which are described by piecewise
linear level set functions. The combination of this strategy for the numerical
integration and the stabilized Nitsche formulation results in an accurate and
robust method. We introduce and analyze it and give numerical examples.


title:
Classification of Neurological Gait Disorders Using Multi-task Feature
  Learning

abstract:
  As our population ages, neurological impairments and degeneration of the
musculoskeletal system yield gait abnormalities, which can significantly reduce
quality of life. Gait rehabilitative therapy has been widely adopted to help
patients maximize community participation and living independence. To further
improve the precision and efficiency of rehabilitative therapy, more objective
methods need to be developed based on sensory data. In this paper, an
algorithmic framework is proposed to provide classification of gait disorders
caused by two common neurological diseases, stroke and Parkinson's Disease
(PD), from ground contact force (GCF) data. An advanced machine learning
method, multi-task feature learning (MTFL), is used to jointly train
classification models of a subject's gait in three classes, post-stroke, PD and
healthy gait. Gait parameters related to mobility, balance, strength and rhythm
are used as features for the classification. Out of all the features used, the
MTFL models capture the more important ones per disease, which will help
provide better objective assessment and therapy progress tracking. To evaluate
the proposed methodology we use data from a human participant study, which
includes five PD patients, three post-stroke patients, and three healthy
subjects. Despite the diversity of abnormalities, the evaluation shows that the
proposed approach can successfully distinguish post-stroke and PD gait from
healthy gait, as well as post-stroke from PD gait, with Area Under the Curve
(AUC) score of at least 0.96. Moreover, the methodology helps select important
gait features to better understand the key characteristics that distinguish
abnormal gaits and design personalized treatment.


title: Pulse profiles and timing of PSR J1757$-$2421

abstract:
  Pulse arrival time measurements over fourteen years with the Nanshan 25-m and
Parkes 64-m radio telescopes have been used to determine the average profile
and timing properties for PSR J1757$-$2421 (B1754$-$24). Analysis of the radio
profile data shows a large variation of spectral index across the profile and
an unusual increase in component separation with increasing frequency. The
timing observations show that PSR B1754$-$24 underwent a large glitch with a
fractional increase in spin frequency of $\Delta\nu_{\rm g}/\nu\sim
7.8\times10^{-6}$ in May 2011. At the time of the glitch there was a large
permanent jump in the rotational frequency accompanied by two exponential
recovery terms with timescales of 15(6) and 97(15) days, respectively.


title:
Distributed Publish/Subscribe Query Processing on the Spatio-Textual
  Data Stream

abstract:
  Huge amount of data with both space and text information, e.g., geo-tagged
tweets, is flooding on the Internet. Such spatio-textual data stream contains
valuable information for millions of users with various interests on different
keywords and locations. Publish/subscribe systems enable efficient and
effective information distribution by allowing users to register continuous
queries with both spatial and textual constraints. However, the explosive
growth of data scale and user base has posed challenges to the existing
centralized publish/subscribe systems for spatio-textual data streams.
  In this paper, we propose our distributed publish/subscribe system, called
PS2Stream, which digests a massive spatio-textual data stream and directs the
stream to target users with registered interests. Compared with existing
systems, PS2Stream achieves a better workload distribution in terms of both
minimizing the total amount of workload and balancing the load of workers. To
achieve this, we propose a new workload distribution algorithm considering both
space and text properties of the data. Additionally, PS2Stream supports dynamic
load adjustments to adapt to the change of the workload, which makes PS2Stream
adaptive. Extensive empirical evaluation, on commercial cloud computing
platform with real data, validates the superiority of our system design and
advantages of our techniques on system performance improvement.


title:
Critical mingling and universal correlations in model binary active
  liquids

abstract:
  Ensembles of driven or motile bodies moving along opposite directions are
generically reported to self-organize into strongly anisotropic lanes. Here,
building on a minimal model of self-propelled bodies targeting opposite
directions, we first evidence a critical phase transition between a mingled
state and a phase-separated lane state specific to active particles. We then
demonstrate that the mingled state displays algebraic structural correlations
also found in driven binary mixtures. Finally, constructing a hydrodynamic
theory, we single out the physical mechanisms responsible for these universal
long-range correlations typical of ensembles of oppositely moving bodies.


title:
Formation and stimulated photodissociation of metastable molecules with
  emission of photon at the collision of two atoms in a laser radiation field

abstract:
  The Formation of metastable molecules (Feshbach resonances) at the collision
of two atoms and subsequent stimulated transition to a lower unbound electronic
molecular state, with emission of a photon of the laser radiation has been
investigated. This can develop, in particular, for $Rb_2$ molecules due to
resonance scattering of two $Rb$ atoms. The considered process is a basis for
the creation of excimer lasers. Expressions for the cross sections of elastic
and inelastic resonance scattering and the intensity of the stimulated emission
of the photons have been obtained.


title: Order statistics of horse racing and the randomly broken stick

abstract:
  We find a remarkable agreement between the statistics of a randomly divided
interval and the observed statistical patterns and distributions found in horse
racing betting markets. We compare the distribution of implied winning odds,
the average true winning probabilities, the implied odds conditional on a win,
and the average implied odds of the winning horse with the corresponding
quantities from the "randomly broken stick problem". We observe that the market
is at least to some degree informationally efficient. From the mapping between
exponential random variables and the statistics of the random division we
conclude that horses' true winning abilities are exponentially distributed.


title:
Chemical abundances in Galactic planetary nebulae from faint emission
  lines

abstract:
  Deep spectrophotometry has proved to be a fundamental tool to improve our
knowledge on the chemical content of planetary nebulae. With the arrival of
very efficient spectrographs installed in the largest ground-based telescopes,
outstanding spectra have been obtained. These data are essential to constrain
state-of-the-art nucleosynthesis models in asymptotic giant branch stars and,
in general, to understand the chemical evolution of our Galaxy. In this paper
we review the last advances on the chemical composition of the ionized gas in
planetary nebulae based on faint emission lines observed through very deep
spectrophotometric data.


title:
Random Spanning Trees for Expanders, Sparsifiers, and Virtual Network
  Security

abstract:
  This work describes probabilistic methods for utilizing random spanning trees
generated via a random walk process. Goyal et al. showed that the union of
random spanning trees approximates the expansion of every cut of a graph.
First, we generalize the method by Goyal et al. for weighted graphs and show
that it is possible to approximate the expansion of every cut in a weighted
graph with the union of random spanning trees generated by a random walk on a
weighted graph. Second, we show that our union of random spanning trees is a
spectral sparsifier of the graph. Moreover, we show that $O(\log n
/\epsilon^2)$ random spanning trees are required in order to spectrally
approximate a bounded degree graph. This result closes a previously open
question on the number of random spanning trees required for saprsification.
Third, we show that our random spanning trees based construction provides
security features for virtual networks, in the context of Software-Defined
Networking. Network virtualization coupled with Software-Defined Networking
allows new on-demand management capabilities. We demonstrate such a service,
namely, on-demand efficient monitoring or anonymity. The proposed service is
based on network virtualization of expanders or sparsifiers over the physical
network. The defined virtual (or overlay) communication graphs coupled with a
multi-hop extension of Valiant randomization based routing lets us monitor the
entire traffic in the network, with a very few monitoring nodes. We propose
methods that theoretically improve services provided by existing monitoring or
anonymity networks, and optimize the degree of monitoring or anonymity.


title: Nuclear excitation by two-photon electron transition

abstract:
  A new mechanism of nuclear excitation via two-photon electron transitions
(NETP) is proposed and studied theoretically. As a generic example, detailed
calculations are performed for the $E1E1$ $1s2s\,^1S_0 \rightarrow 1s^2\,^1S_0$
two-photon decay of He-like $^{225}$Ac$^{87+}$ ion with the resonant excitation
of the $3/2+$ nuclear state with the energy 40.09(5) keV. The probability for
such a two-photon decay via the nuclear excitation is found to be $P_{\rm NETP}
= 3.5 \times 10^{-9}$ and, thus, is comparable with other mechanisms, such as
nuclear excitation by electron transition and by electron capture. The
possibility for the experimental observation of the proposed mechanism is
thoroughly discussed.


title:
Composite device for interfacing an array of atoms with a single
  nanophotonic cavity mode

abstract:
  We propose a method of trapping atoms in arrays near to the surface of a
composite nanophotonic device with optimal coupling to a single cavity mode.
The device, comprised of a nanofiber mounted on a grating, allows the formation
of periodic optical trapping potentials near to the nanofiber surface along
with a high cooperativity nanofiber cavity. We model the device analytically
and find good agreement with numerical simulations. We numerically demonstrate
that for an experimentally realistic device, an array of traps can be formed
whose centers coincide with the antinodes of a single cavity mode, guaranteeing
optimal coupling to the cavity. Additionally, we simulate a trap suitable for a
single atom within 100 nm of the fiber surface, potentially allowing larger
coupling to the nanofiber than found using typical guided mode trapping
techniques.


title:
Predicting brain age with deep learning from raw imaging data results in
  a reliable and heritable biomarker

abstract:
  Machine learning analysis of neuroimaging data can accurately predict
chronological age in healthy people and deviations from healthy brain ageing
have been associated with cognitive impairment and disease. Here we sought to
further establish the credentials of "brain-predicted age" as a biomarker of
individual differences in the brain ageing process, using a predictive
modelling approach based on deep learning, and specifically convolutional
neural networks (CNN), and applied to both pre-processed and raw T1-weighted
MRI data. Firstly, we aimed to demonstrate the accuracy of CNN brain-predicted
age using a large dataset of healthy adults (N = 2001). Next, we sought to
establish the heritability of brain-predicted age using a sample of monozygotic
and dizygotic female twins (N = 62). Thirdly, we examined the test-retest and
multi-centre reliability of brain-predicted age using two samples
(within-scanner N = 20; between-scanner N = 11). CNN brain-predicted ages were
generated and compared to a Gaussian Process Regression (GPR) approach, on all
datasets. Input data were grey matter (GM) or white matter (WM) volumetric maps
generated by Statistical Parametric Mapping (SPM) or raw data. Brain-predicted
age represents an accurate, highly reliable and genetically-valid phenotype,
that has potential to be used as a biomarker of brain ageing. Moreover, age
predictions can be accurately generated on raw T1-MRI data, substantially
reducing computation time for novel data, bringing the process closer to giving
real-time information on brain health in clinical settings.


title: Quantum uncertainty relation using coherence

abstract:
  Measurement outcomes of a quantum state can be genuinely random
(unpredictable) according to the basic laws of quantum mechanics. The
Heisenberg-Robertson uncertainty relation puts constrains on the accuracy of
two noncommuting observables. The existing uncertainty relations adopt variance
or entropic measures, which are functions of observed outcome distributions, to
quantify the uncertainty. According to recent studies of quantum coherence,
such uncertainty measures contain both classical (predictable) and quantum
(unpredictable) components. In order to extract out the quantum effects, we
define quantum uncertainty to be the coherence of the state on the measurement
basis. We discover a quantum uncertainty relation of coherence between two
measurement non-commuting bases. Furthermore, we analytically derive the
quantum uncertainty relation for the qubit case with three widely adopted
coherence measures, the relative entropy using coherence, the coherence of
formation, and the $l_1$ norm of coherence.


title:
Optimal Pilot and Payload Power Control in Single-Cell Massive MIMO
  Systems

abstract:
  This paper considers the jointly optimal pilot and data power allocation in
single-cell uplink massive multiple-input-multiple-output (MIMO) systems. Using
the spectral efficiency (SE) as performance metric and setting a total energy
budget per coherence interval, the power control is formulated as optimization
problems for two different objective functions: the weighted minimum SE among
the users and the weighted sum SE. A closed form solution for the optimal
length of the pilot sequence is derived. The optimal power control policy for
the former problem is found by solving a simple equation with a single
variable. Utilizing the special structure arising from imperfect channel
estimation, a convex reformulation is found to solve the latter problem to
global optimality in polynomial time. The gain of the optimal joint power
control is theoretically justified, and is proved to be large in the low SNR
regime. Simulation results also show the advantage of optimizing the power
control over both pilot and data power, as compared to the cases of using full
power and of only optimizing the data powers as done in previous work.


title:
Filter sharing: Efficient learning of parameters for volumetric
  convolutions

abstract:
  Typical convolutional neural networks (CNNs) have several millions of
parameters and require a large amount of annotated data to train them. In
medical applications where training data is hard to come by, these
sophisticated machine learning models are difficult to train. In this paper, we
propose a method to reduce the inherent complexity of CNNs during training by
exploiting the significant redundancy that is noticed in the learnt CNN
filters. Our method relies on finding a small set of filters and mixing
coefficients to derive every filter in each convolutional layer at the time of
training itself, thereby reducing the number of parameters to be trained. We
consider the problem of 3D lung nodule segmentation in CT images and
demonstrate the effectiveness of our method in achieving good results with only
few training examples.


title: Quantum embedding theories

abstract:
  In complex systems, it is often the case that the region of interest forms
only one part of a much larger system. The idea of joining two different
quantum simulations - a high level calculation on the active region of
interest, and a low level calculation on its environment - formally defines a
quantum embedding. While any combination of techniques constitutes an
embedding, several rigorous formalisms have emerged that provide for exact
feedback between the embedded system and its environment. These three
formulations: it density functional embedding, Green's function embedding, and
density matrix embedding, respectively use the single-particle density,
single-particle Green's function, and single-particle density matrix as the
quantum variables of interest. Many excellent reviews exist covering these
methods individually. However, a unified presentation of the different
formalisms is so far lacking. Indeed, the various languages commonly used:
functional equations for density functional embedding; diagrammatics for
Green's function embedding; and entanglement arguments for density matrix
embedding, make the three formulations appear vastly different. In this
account, we introduce the basic equations of all three formulations in such a
way as to highlight their many common intellectual strands. While we focus
primarily on a straightforward theoretical perspective, we also give a brief
overview of recent applications, and possible future developments.


title:
Measurement of the $W$ boson polarisation in $t\bar{t}$ events from $pp$
  collisions at $\sqrt{s}$ = 8 TeV in the lepton+jets channel with ATLAS

abstract:
  This paper presents a measurement of the polarisation of $W$ bosons from
$t\bar{t}$ decays, reconstructed in events with one high-$p_{\mbox{T}}$ lepton
and at least four jets. Data from $pp$ collisions at the LHC were collected at
$\sqrt{s}$ = 8 TeV and correspond to an integrated luminosity of 20.2
fb$^{-1}$. The angle $\theta^{*}$ between the $b$-quark from the top quark
decay and a direct $W$ boson decay product in the $W$ boson rest frame is
sensitive to the $W$ boson polarisation. Two different $W$ decay products are
used as polarisation analysers: the charged lepton and the down-type quark for
the leptonically and hadronically decaying $W$ boson, respectively. The most
precise measurement of the $W$ boson polarisation via the distribution of
$\cos{\theta^{*}}$ is obtained using the leptonic analyser and events in which
at least two of the jets are tagged as $b$-quark jets. The fitted fractions of
longitudinal, left- and right-handed polarisation states are $F_{\mathrm{0}}=
0.709 \pm {0.019}$, $F_{\mathrm{L}}= 0.299 \pm {0.015}$ and $F_{\mathrm{R}}=
-0.008 \pm {0.014}$, and are the most precisely measured $W$ boson polarisation
fractions to date. Limits on anomalous couplings of the $Wtb$ vertex are set.


title:
Cosmogenic neutrinos and gamma-rays and the redshift evolution of UHECR
  sources

abstract:
  If ultra-high-energy cosmic rays (UHECRs) have extragalactic origins, as is
widely assumed to be the case at least for the majority of cosmic rays with
energies above a few EeV, secondary neutrinos and photons can be expected to be
produced during the propagation of UHECRs through intergalactic space via
interactions with cosmic background photons. The fluxes of such secondary
particles are strongly dependent on the redshift evolution of the emissivity
(number density times luminosity) of UHECR sources. We show how cosmic rays,
neutrinos, and gamma rays can potentially provide complementary information
about UHECR source evolution.


title:
Robust identification of harmonic oscillator parameters using the
  adjoint Fokker-Planck equation

abstract:
  We present a model-based output-only method for identifying from time series
the parameters governing the dynamics of stochastically forced oscillators. In
this context, suitable models of the oscillator's damping and stiffness
properties are postulated, guided by physical understanding of the oscillatory
phenomena. The temporal dynamics and the probability density function of the
oscillation amplitude are described by a Langevin equation and its associated
Fokker-Planck equation, respectively. One method consists in fitting the
postulated analytical drift and diffusion coefficients with their estimated
values, obtained from data processing by taking the short-time limit of the
first two transition moments. However, this limit estimation loses robustness
in some situations - for instance when the data is band-pass filtered to
isolate the spectral contents of the oscillatory phenomena of interest. In this
paper, we use a robust alternative where the adjoint Fokker-Planck equation is
solved to compute Kramers-Moyal coefficients exactly, and an iterative
optimisation yields the parameters that best fit the observed statistics
simultaneously in a wide range of amplitudes and time scales. The method is
illustrated with a stochastic Van der Pol oscillator serving as a prototypical
model of thermoacoustic instabilities in practical combustors, where system
identification is highly relevant to control.


title: Limits of random tree-like discrete structures

abstract:
  We study a model of random $\mathcal{R}$-enriched trees that is based on
weights on the $\mathcal{R}$-structures and allows for a unified treatment of a
large family of random discrete structures. We establish distributional limits
describing local convergence around fixed and random points in this general
context, limit theorems for component sizes when $\mathcal{R}$ is a composite
class, and a Gromov--Hausdorff scaling limit of random metric spaces patched
together from independently drawn metrics on the $\mathcal{R}$-structures. Our
main applications treat a selection of examples encompassed by this model. We
consider random outerplanar maps sampled according to arbitrary weights
assigned to their inner faces, and classify in complete generality
distributional limits for both the asymptotic local behaviour near the
root-edge and near a uniformly at random drawn vertex. We consider random
connected graphs drawn according to weights assigned to their blocks and
establish a Benjamini--Schramm limit. We also apply our framework to recover in
a probabilistic way a central limit theorem for the size of the largest
$2$-connected component in random graphs from planar-like classes. We prove
Benjamini--Schramm convergence of random $k$-dimensional trees and establish
both scaling limits and local weak limits for random planar maps drawn
according to Boltzmann-weights assigned to their $2$-connected components.


title: Tropical Computations in polymake

abstract:
  We give an overview of recently implemented polymake features for
computations in tropical geometry. The main focus is on explicit examples
rather than technical explanations. Our computations employ tropical
hypersurfaces, moduli of tropical plane curves, tropical linear spaces and
Grassmannians, lines on tropical cubic surfaces as well as intersection rings
of matroids


title: Faithful Actions from Hyperplane Arrangements

abstract:
  We show that if $X$ is a smooth quasi-projective $3$-fold admitting a
flopping contraction, then the fundamental group of an associated simplicial
hyperplane arrangement acts faithfully on the derived category of $X$. The main
technical advance is to use torsion pairs as an efficient mechanism to track
various objects under iterations of the flop functor (respectively, mutation
functor). This allows us to relate compositions of the flop functor
(respectively, mutation functor) to the theory of Deligne normal form, and to
give a criterion for when a finite composition of $3$-fold flops can be
understood as a tilt at a single torsion pair. We also use this technique to
give a simplified proof of the result of Brav-Thomas for Kleinian
singularities.


title:
From Motion Blur to Motion Flow: a Deep Learning Solution for Removing
  Heterogeneous Motion Blur

abstract:
  Removing pixel-wise heterogeneous motion blur is challenging due to the
ill-posed nature of the problem. The predominant solution is to estimate the
blur kernel by adding a prior, but the extensive literature on the subject
indicates the difficulty in identifying a prior which is suitably informative,
and general. Rather than imposing a prior based on theory, we propose instead
to learn one from the data. Learning a prior over the latent image would
require modeling all possible image content. The critical observation
underpinning our approach is thus that learning the motion flow instead allows
the model to focus on the cause of the blur, irrespective of the image content.
This is a much easier learning task, but it also avoids the iterative process
through which latent image priors are typically applied. Our approach directly
estimates the motion flow from the blurred image through a fully-convolutional
deep neural network (FCN) and recovers the unblurred image from the estimated
motion flow. Our FCN is the first universal end-to-end mapping from the blurred
image to the dense motion flow. To train the FCN, we simulate motion flows to
generate synthetic blurred-image-motion-flow pairs thus avoiding the need for
human labeling. Extensive experiments on challenging realistic blurred images
demonstrate that the proposed method outperforms the state-of-the-art.


title:
Landauer-B\"uttiker approach for hyperfine mediated electronic transport
  in the integer quantum Hall regime

abstract:
  The interplay of spin-polarized electronic edge states with the dynamics of
the host nuclei in quantum Hall systems presents rich and non-trivial transport
physics. Here, we develop a Landauer-B\"uttiker approach to understand various
experimental features observed in the integer quantum Hall set ups featuring
quantum point contacts. The approach developed here entails a phenomenological
description of spin resolved inter-edge scattering induced via hyperfine
assisted electron-nuclear spin flip-flop processes. A self-consistent
simulation framework between the nuclear spin dynamics and edge state
electronic transport is presented in order to gain crucial insights into the
dynamic nuclear polarization effects on electronic transport and in turn the
electron-spin polarization effects on the nuclear spin dynamics. In particular,
we show that the hysteresis noted experimentally in the conductance-voltage
trace as well as in the resistively detected NMR lineshape results from a lack
of quasi-equilibrium between electronic transport and nuclear polarization
evolution. In addition, we present circuit models to emulate such hyperfine
mediated transport effects to further facilitate a clear understanding of the
electronic transport processes occurring around the quantum point contact.
Finally, we extend our model to account for the effects of quadrupolar
splitting of nuclear levels and also depict the electronic transport signatures
that arise from single and multi-photon processes.


title:
Turbulent diffusion of chemically reacting flows: theory and numerical
  simulations

abstract:
  The theory of turbulent diffusion of chemically reacting gaseous admixtures
developed previously (Phys. Rev. E {\bf 90}, 053001, 2014) is generalized for
large yet finite Reynolds numbers, and the dependence of turbulent diffusion
coefficient versus two parameters, the Reynolds number and Damk\"ohler number
(which characterizes a ratio of turbulent and reaction time scales) is
obtained. Three-dimensional direct numerical simulations (DNS) of a finite
thickness reaction wave for the first-order chemical reactions propagating in
forced, homogeneous, isotropic, and incompressible turbulence are performed to
validate the theoretically predicted effect of chemical reactions on turbulent
diffusion. It is shown that the obtained DNS results are in a good agreement
with the developed theory.


title: Gravitational Particle Creation in a Stiff Matter Dominated Universe

abstract:
  A scenario for gravitational particle creation in a stiff matter dominated
flat Friedmann-Robertson-Walker universe is presented. The primary creation of
scalar particles is calculated using quantum field theory in curved spacetime
and it is found to be strongly dependent on the scalar mass and the expansion
parameter of the universe. The particle creation is most effective for a very
massive scalar field and large expansion parameter. We apply the results to
cosmology and calculate an upper bound for the equilibrium temperature of the
secondary particles created by the scalar field decay.


title:
Inverses, Conditionals and Compositional Operators in Separative
  Valuation Algebra

abstract:
  Compositional models were introduce by Jirousek and Shenoy in the general
framework of valuation-based systems. They based their theory on an axiomatic
system of valuations involving not only the operations of combination and
marginalisation, but also of removal. They claimed that this systems covers
besides the classical case of discrete probability distributions, also the
cases of Gaussian densities and belief functions, and many other systems.
  Whereas their results on the compositional operator are correct, the
axiomatic basis is not sufficient to cover the examples claimed above. We
propose here a different axiomatic system of valuation algebras, which permits
a rigorous mathematical theory of compositional operators in valuation-based
systems and covers all the examples mentioned above. It extends the classical
theory of inverses in semigroup theory and places thereby the present theory
into its proper mathematical frame. Also this theory sheds light on the
different structures of valuation-based systems, like regular algebras
(represented by probability potentials), canncellative algebras (Gaussian
potentials) and general separative algebras (density functions).


title:
Long period variable stars in NGC 147 and NGC 185. I. Their star
  formation histories

abstract:
  NGC 147 and NGC 185 are two of the most massive satellites of the Andromeda
galaxy (M 31). Close together in the sky, of similar mass and morphological
type dE, they possess different amounts of interstellar gas and tidal
distortion. The question therefore is, how do their histories compare? Here we
present the first reconstruction of the star formation histories of NGC 147 and
NGC 185 using long-period variable stars. These represent the final phase of
evolution of low- and intermediate-mass stars at the asymptotic giant branch,
when their luminosity is related to their birth mass. Combining near-infrared
photometry with stellar evolution models, we construct the mass function and
hence the star formation history. For NGC 185 we found that the main epoch of
star formation occurred 8.3 Gyr ago, followed by a much lower, but relatively
constant star formation rate. In the case of NGC 147, the star formation rate
peaked only 7 Gyr ago, staying intense until ~ 3 Gyr ago, but no star formation
has occurred for at least 300 Myr. Despite their similar masses, NGC 147 has
evolved more slowly than NGC 185 initially, but more dramatically in more
recent times. This is corroborated by the strong tidal distortions of NGC 147
and the presence of gas in the centre of NGC 185.


title:
Multi-source Transfer Learning with Convolutional Neural Networks for
  Lung Pattern Analysis

abstract:
  Early diagnosis of interstitial lung diseases is crucial for their treatment,
but even experienced physicians find it difficult, as their clinical
manifestations are similar. In order to assist with the diagnosis,
computer-aided diagnosis (CAD) systems have been developed. These commonly rely
on a fixed scale classifier that scans CT images, recognizes textural lung
patterns and generates a map of pathologies. In a previous study, we proposed a
method for classifying lung tissue patterns using a deep convolutional neural
network (CNN), with an architecture designed for the specific problem. In this
study, we present an improved method for training the proposed network by
transferring knowledge from the similar domain of general texture
classification. Six publicly available texture databases are used to pretrain
networks with the proposed architecture, which are then fine-tuned on the lung
tissue data. The resulting CNNs are combined in an ensemble and their fused
knowledge is compressed back to a network with the original architecture. The
proposed approach resulted in an absolute increase of about 2% in the
performance of the proposed CNN. The results demonstrate the potential of
transfer learning in the field of medical image analysis, indicate the textural
nature of the problem and show that the method used for training a network can
be as important as designing its architecture.


title: Scene Flow Estimation: A Survey

abstract:
  This paper is the first to review the scene flow estimation field, which
analyzes and compares methods, technical challenges, evaluation methodologies
and performance of scene flow estimation. Existing algorithms are categorized
in terms of scene representation, data source, and calculation scheme, and the
pros and cons in each category are compared briefly. The datasets and
evaluation protocols are enumerated, and the performance of the most
representative methods is presented. A future vision is illustrated with few
questions arisen for discussion. This survey presents a general introduction
and analysis of scene flow estimation.


title: The Auslander-Reiten duality via morphisms determined by objects

abstract:
  Given an exact category $\mathcal{C}$, we denote by $\mathcal{C}_l$ the
smallest additive subcategory containing injectives and indecomposable objects
which appear as the first term of an almost split conflation. We prove that a
deflation is right determined by some object if and only if its intrinsic
kernel lies in $\mathcal{C}_l$. We give characterizations for $\mathcal{C}$
having Auslander-Reiten duality.


title: Local correlation entropy

abstract:
  Local correlation entropy, introduced by Takens in 1983, represents the
exponential decay rate of the relative frequency of recurrences in the
trajectory of a point, as the embedding dimension grows to infinity. In this
paper we study relationship between the supremum of local correlation entropies
and the topological entropy. For dynamical systems on graphs we prove that the
two quantities coincide. Moreover, there is an uncountable set of points with
local correlation entropy arbitrarily close to the topological entropy. On the
other hand, we construct a strictly ergodic subshift with positive topological
entropy having all local correlation entropies equal to zero. As a necessary
tool, we derive an expected relationship between the local correlation
entropies of a system and those of its iterates.


title: Viscosity bound for anisotropic superfluids with dark matter sector

abstract:
  The shear viscosity to the entropy density ratio $\eta/s$ of the anisotropic
superfluid has been calculated by means of the gauge/gravity duality in the
presence of the {\it dark matter} sector. The {\it dark matter} has been
described by the Yang-Mills field analogous to the one describing visible
matter sector and it is assumed to interact with the visible field with
coupling constant $\alpha$. Close to the superfluid transition temperature
($T_c$) the analytical solution has been given up to the leading order in a
symmetry breaking parameter and the ratio of the gravitational constant and
Yang-Mils coupling. The tensor element of ratio $\eta/s$ remains unaffected by
the {\it dark matter} for the viscosity tensor in the plane perpendicular to
the symmetry breaking direction (here $yz$). The temperature dependence and the
linear correction in $(1-\alpha)$ in the plane containing this direction (here
$xy$) was also revealed. The correction linearly vanishes for temperature
tending to the critical one $T\rightarrow T_c$.


title: Sharp Strichartz estimates in spherical coordinates

abstract:
  We prove almost Strichartz estimates found after adding regularity in the
spherical coordinates for Schr\"odinger-like equations. The estimates are sharp
up to endpoints. The proof relies on estimates involving spherical averages.
Sharpness is discussed making use of a modified Knapp-type example.


title:
Stable Collective Dynamics of Two-Level Systems Coupled by Dipole
  Interactions

abstract:
  We study the dynamics of a set of two-level systems coupled by dipolar
interactions under a resonant external Rabi drive. The two-level systems are
prepared initially in a coherent product state, and we ask how the
non-equilibrium conditions caused by the drive affect this coherence. We study
the full non-linear dynamics of the coupled two-level systems within a
classical approximation by analysing numerically the equations of motion and
determining the stability of the collective coherent state within classical
Floquet theory. We establish the behaviour analytically in the high Rabi
coupling limit by employing a Magnus expansion and spin wave analysis. Our
results show that, typically, the dipole interactions between the two-level
systems lead to instabilities that cause a breakdown of the collective Rabi
oscillations. However, we identify parameter regimes for which the two-level
systems undergo collective coherent Rabi oscillations even in the presence of
the dipole interactions.


title: Generalized Inhomogeneous Strichartz estimates

abstract:
  We prove new inhomogeneous generalized Strichartz estimates, which do not
follow from the homogeneous generalized estimates by virtue of the
Christ-Kiselev lemma. Instead, we make use of the bilinear interpolation
argument worked out by Keel and Tao and refined by Foschi presented in a
unified framework. Finally, we give a sample application.


title:
Addressing electron-hole correlation in core excitations of solids: An
  all-electron many-body approach from first principles

abstract:
  We present an ab initio study of core excitations of solid-state materials
focussing on the role of electron-hole correlation. In the framework of an
all-electron implementation of many-body perturbation theory into the exciting
code, we investigate three different absorption edges of three materials,
spanning a broad energy window, with transition energies between a few hundred
to thousands of eV. Specifically, we consider excitations from the Ti $K$ edge
in rutile and anatase $\textrm{TiO}_2$, from the Pb $M_4$ edge in
$\textrm{PbI}_2$, and from the Ca $L_{2,3}$ edge in $\textrm{CaO}$. We show
that the electron-hole attraction rules x-ray absorption for deep core states,
when local fields play a minor role. On the other hand, the local-field effects
introduced by the exchange interaction between the excited electron and the
hole dominate excitation processes from shallower core levels, separated by a
spin-orbit splitting of a few eV. Our approach yields absorption spectra in
good agreement with available experimental data, and allows for an in-depth
analysis of the results, revealing the electronic contributions to the
excitations, as well as their spatial distribution.


title: Hiding neutrino mass in modified gravity cosmologies

abstract:
  Cosmological observables show a dependence with the neutrino mass, which is
partially degenerate with parameters of extended models of gravity. We study
and explore this degeneracy in Horndeski generalized scalar-tensor theories of
gravity. Using forecasted cosmic microwave background and galaxy power spectrum
datasets, we find that a single parameter in the linear regime of the effective
theory dominates the correlation with the total neutrino mass. For any given
mass, a particular value of this parameter approximately cancels the power
suppression due to the neutrino mass at a given redshift. The extent of the
cancellation of this degeneracy depends on the cosmological large-scale
structure data used at different redshifts. We constrain the parameters and
functions of the effective gravity theory and determine the influence of
gravity on the determination of the neutrino mass from present and future
surveys.


title: $^3$He Abundances in Planetary Nebulae

abstract:
  The $^3$He isotope is important to many fields of astrophysics, including
stellar evolution, chemical evolution, and cosmology. The isotope is produced
in stars which evolve through the planetary nebula phase. Planetary nebulae are
the final evolutionary phase of low- and intermediate-mass stars, where the
extensive mass lost by the star on the asymptotic giant branch is ionised by
the emerging white dwarf. This ejecta quickly disperses and merges with the
surrounding ISM. The abundance of $^3$He can only be derived from the hyperfine
transition of the ionised $^3$He, which is represented as $^3$He$^+$, these
transition can be observed in the radio at the rest frequency of 8.665 GHz.
$^3$He abundances in PNe can help test models of the chemical evolution of the
Galaxy. Many hours have been put into trying to detect this line, using
telescopes like Effelsberg a 100m dish from the Max Planck Institute for Radio
Astronomy, the National Radio Astronomy Observatory (NRAO) 140-foot telescope,
the NRAO Very Large Array, the Arecibo antenna, the Green Bank Telescope, and
only just recently, the Deep Space Station 63 antenna from the Madrid Deep
Space Communications Complex.


title: Tripartite entanglement of fermionic system in accelerated frames

abstract:
  The dynamics of tripartite entanglement of fermionic system in noninertial
frames through linear contraction criterion when one or two observers are
accelerated is investigated. In one observer accelerated case the entanglement
measurement is not invariant with respect to the partial realignment of
different subsystems and for two observers accelerated case it is invariant. It
is shown that the acceleration of the frame does not generate entanglement in
any bipartite subsystems. Unlike the bipartite states, the genuine tripartite
entanglement does not completely vanish in both one observer accelerated and
two observers accelerated cases even in the limit of infinite acceleration. The
degradation of tripartite entanglement is fast when two observers are
accelerated than when one observer is accelerated. It is shown that tripartite
entanglement is a better resource for quantum information processing than the
bipartite entanglement in noninertial frames .


title: Two-body bound and edge states in the extended SSH Bose-Hubbard model

abstract:
  We study the bosonic two-body problem in a Su-Schrieffer-Heeger dimerized
chain with on-site and nearest-neighbor interactions. We find two classes of
bound states. The first, similar to the one induced by on-site interactions,
has its center of mass on the strong link, whereas the second, existing only
thanks to nearest-neighbors interactions, is centered on the weak link. We
identify energy crossings between these states and analyse them using exact
diagonalization and perturbation theory. In the presence of open boundary
conditions, novel strongly-localized edge-bound states appear in the spectrum
as a consequence of the interplay between lattice geometry, on-site and
nearest-neighbor interactions. Contrary to the case of purely on-site
interactions, such EBS persist even in the strongly interacting regime.


title: Nuclear Clustering in Fermionic Molecular Dynamics

abstract:
  Clustering plays an important role in the structure of nuclei, especially for
light nuclei in the $p$-shell. In nuclear cluster models these degrees of
freedom are introduced explicitly. In the Resonating Group Method or in the
Generator Coordinate Method the clusters are built from individual nucleons
interacting via an effective nucleon-nucleon interaction; the total wave
function is antisymmetrized. Fermionic Molecular Dynamics (FMD) goes beyond
pure cluster models. It is a microscopic many-body approach using a Gaussian
wave packet basis that includes the harmonic oscillator shell model and
Brink-type cluster model wave functions as special cases. Clustering is not
imposed but appears dynamically in the calculations. The importance of
clustering for the understanding of bound states, resonances and scattering
states is illustrated with examples discussing the charge radii of the Neon
isotopes, the $^3$He($\alpha$,$\gamma$)$^7$Be capture reaction and the cluster
states in the $^{12}$C continuum.


title: Compact CAR: Low-Overhead Cache Replacement Policy for an ICN Router

abstract:
  Information-centric networking (ICN) has gained attention from network
research communities due to its capability of efficient content dissemination.
In-network caching function in ICN plays an important role to achieve the
design motivation. However, many researchers on in-network caching have focused
on where to cache rather than how to cache: the former is known as contents
deployment in the network and the latter is known as cache replacement in an
ICN element. Although, the cache replacement has been intensively researched in
the context of web-caching and content delivery network previously, the
conventional approaches cannot be directly applied to ICN due to the fine
granularity of cacheable items in ICN, which eventually changes the access
patterns.
  In this paper, we argue that ICN requires a novel cache replacement algorithm
to fulfill the requirements in the design of high performance ICN element.
Then, we propose a novel cache replacement algorithm to satisfy the
requirements named Compact CLOCK with Adaptive Replacement (Compact CAR), which
can reduce the consumption of cache memory to one-tenth compared to
conventional approaches.


title:
Manifolds of absolutely continuous curves and the square root velocity
  framework

abstract:
  A classical result in Riemannian geometry states that the absolutely
continuous curves into a (finite-dimensional) Riemannian manifold form an
infinite-dimensional manifold. In the present paper this construction and
related results are generalised to absolutely continuous curves with values in
a strong Riemannian manifolds. As an application we consider extensions of the
square root velocity transform (SRVT) framework for shape analysis.
Computations in this framework frequently lead to curves which leave the shape
space (of smooth curves), and are only contained in a completion. In the vector
valued case, this extends the SRVT to a space of absolutely continuous curves.
We investigate the situation for shape spaces of manifold valued (absolutely
continuous) curves.


title: Towards Information-Seeking Agents

abstract:
  We develop a general problem setting for training and testing the ability of
agents to gather information efficiently. Specifically, we present a collection
of tasks in which success requires searching through a partially-observed
environment, for fragments of information which can be pieced together to
accomplish various goals. We combine deep architectures with techniques from
reinforcement learning to develop agents that solve our tasks. We shape the
behavior of these agents by combining extrinsic and intrinsic rewards. We
empirically demonstrate that these agents learn to search actively and
intelligently for new information to reduce their uncertainty, and to exploit
information they have already acquired.


title: Aerial Picking and Delivery of Magnetic Objects with MAVs

abstract:
  Autonomous delivery of goods using a MAV is a difficult problem, as it poses
high demand on the MAV's control, perception and manipulation capabilities.
This problem is especially challenging if the exact shape, location and
configuration of the objects are unknown. In this paper, we report our findings
during the development and evaluation of a fully integrated system that is
energy efficient and enables MAVs to pick up and deliver objects with partly
ferrous surface of varying shapes and weights. This is achieved by using a
novel combination of an electro-permanent magnetic gripper with a passively
compliant structure and integration with detection, control and servo
positioning algorithms. The system's ability to grasp stationary and moving
objects was tested, as well as its ability to cope with different shapes of the
object and external disturbances. We show that such a system can be
successfully deployed in scenarios where an object with partly ferrous parts
needs to be gripped and placed in a predetermined location.


title: Tangent categories of algebras over operads

abstract:
  Associated to a presentable $\infty$-category $\mathcal{C}$ and an object $X
\in \mathcal{C}$ is the tangent $\infty$-category $\mathcal{T}_X\mathcal{C}$,
consisting of parameterized spectrum objects over $X$. This gives rise to a
cohomology theory, called Quillen cohomology, whose category of coefficients is
$\mathcal{T}_X\mathcal{C}$. When $\mathcal{C}$ consists of algebras over a nice
$\infty$-operad in a stable $\infty$-category, $\mathcal{T}_X\mathcal{C}$ is
equivalent to the $\infty$-category of operadic modules, by work of
Basterra--Mandell, Schwede and Lurie. In this paper we develop the
model-categorical counterpart of this identification and extend it to the case
of algebras over an enriched operad, taking values in a model category which is
not necessarily stable. This extended comparison can be used, for example, to
identify the cotangent complex of enriched categories, an application we take
up in a subsequent paper.


title:
The abstract cotangent complex and Quillen cohomology of enriched
  categories

abstract:
  In his fundamental work, Quillen developed the theory of the cotangent
complex as a universal abelian derived invariant, and used it to define and
study a canonical form of cohomology, encompassing many known cohomology
theories. Additional cohomology theories, such as generalized cohomology of
spaces and topological Andr\'e-Quillen cohomology, can be accommodated by
considering a spectral version of the cotangent complex. Recent work of Lurie
established a comprehensive $\infty$-categorical analogue of the cotangent
complex formalism using stabilization of $\infty$-categories. In this paper we
study the spectral cotangent complex while working in Quillen's model
categorical setting. Our main result gives new and explicit computations of the
cotangent complex and Quillen cohomology of enriched categories. For this we
make essential use of previous work, which identifies the tangent categories of
operadic algebras in unstable model categories. In particular, we present the
cotangent complex of an $\infty$-category as a spectrum valued functor on its
twisted arrow category, and consider the associated obstruction theory in some
examples of interest.


title: Quantifying acoustic damping using flame chemiluminescence

abstract:
  Thermoacoustic instabilities in gas turbines and aeroengine combustors falls
within the category of complex systems. They can be described
phenomenologically using nonlinear stochastic differential equations, which
constitute the grounds for output-only model-based system identification. It
has been shown recently that one can extract the governing parameters of the
instabilities, namely the linear growth rate and the nonlinear component of the
thermoacoustic feedback, using dynamic pressure time series only. This is
highly relevant for practical systems, which cannot be actively controlled due
to a lack of cost-effective actuators. The thermoacoustic stability is given by
the linear growth rate, which results from the combination of the acoustic
damping and the coherent feedback from the flame. In this paper, it is shown
that it is possible to quantify the acoustic damping of the system, and thus to
separate its contribution to the linear growth rate from the one of the flame.
This is achieved by post-processing in a simple way simultaneously acquired
chemiluminescence and acoustic pressure data. It provides an additional
approach to further unravel from observed time series the key mechanisms
governing the system dynamics. This straightforward method is illustrated here
using experimental data from a combustion chamber operated at several linearly
stable and unstable operating conditions.


title: Statistical properties of the Bipolar Magnetic Regions

abstract:
  Using the observations from Michelson Doppler Imager (MDI) onboard Solar and
Heliospheric Observatory (SOHO), we develop a computational algorithm to
automatically identify the bipolar magnetic regions (BMRs) in the active
regions, and then study their statistical properties. The individual magnetic
(positive or negative) pole of the BMR is determined from the region with an
absolute strength above 55 G and with an area above 250 pixel^2 (495 Mm^2),
while a BMR is identified as a pair of positive and negative poles with a
shortest area-weight distance between them. Based on this method, 2234 BMRs are
identified from the MDI synoptic magnetograms between the Carrington Rotation
1909 (1996 May 06) and 2104 (2010 December 10). 1005 of them are located in the
northern hemisphere, while the other 1229 are in the southern hemisphere.We
find that the BMR paraments (e.g., latitudes, separations, fragments, and
strength) are similar to those of active regions (ARs). Moreover, based on the
maximum likelihood estimation (MLE)method, the frequency distributions of these
BMRs occurrence as functions of area size and magnetic flux exhibit a power-law
behavior. We also find that their orientation angles follow the Hale's Polarity
Laws and deviate slightly to the solar equator direction. Consistent with the
previous findings, we obtain the orientation angles dependence on the latitudes
for the normal BMRs during the 23rd solar cycle. The north-south asymmetry of
these BMRs is also detected here.


title:
Suppressed Quenching and Strong Coupling of Purcell-Enhanced
  Single-Molecule Emission in Plasmonic Nanocavities

abstract:
  An emitter in the vicinity of a metal nanostructure is quenched by its decay
through non-radiative channels, leading to the belief in a zone of inactivity
for emitters placed within $<$10nm of a plasmonic nanostructure. Here we
demonstrate that in tightly-coupled plasmonic resonators forming nanocavities
"quenching is quenched" due to plasmon mixing. Unlike isolated nanoparticles,
plasmonic nanocavities show mode hybridization which massively enhances emitter
excitation and decay via radiative channels. This creates ideal conditions for
realizing single-molecule strong-coupling with plasmons, evident in dynamic
Rabi-oscillations and experimentally confirmed by laterally dependent emitter
placement through DNA-origami.


title: Off-Shell Covariantization of Algebroid Gauge Theories

abstract:
  We present a generalized method to construct field strengths and gauge
symmetries, which yield a Yang-Mills type action with Lie n-algebroid gauge
symmetry. The procedure makes use of off-shell covariantization in a
supergeometric setting. We apply this method to the system of a 1-form gauge
field and scalar fields with Lie n-algebroid gauge symmetry. We work out some
characteristic examples.


title:
Faddeev fixed center approximation to $\pi \bar{K} K^*$ system and the
  $\pi_1(1600)$

abstract:
  We investigate the three-body system of $\pi \bar{K} K^*$ by using the
fixed-center approximation to the Faddeev equation, taking the interaction
between $\pi$ and $\bar{K}$, $\pi$ and $K^*$, and $\bar{K}$ and $K^*$ from the
chiral unitary approach. The study is made assuming scattering of a $\pi$ on a
$\bar{K} K^*$ cluster, which is known to generate the $f_1(1285)$ state. The
resonant structure around $1650$ MeV shows up in the modulus squared of the
$\pi$-$(\bar{K} K^*)_{f_1(1285)}$ scattering amplitude and suggests that a
$\pi$-$(\bar{K} K^*)_{f_1(1285)}$ state, with "exotic" quantum numbers $J^{PC}
= 1^{-+}$, can be formed. This state can be identified as the observed
$\pi_1(1600)$ resonance. We suggest that this is the origin of the present
$\pi_1(1600)$ resonance and propose to look at the $\pi f_1(1285)$ mode in
future experiments to clarify the issue.


title: Edge states of mechanical diamond and its topological origin

abstract:
  A mechanical diamond, a classical mechanics of a spring-mass model arrayed on
a diamond lattice, is discussed topologically. Its frequency dispersion
possesses an intrinsic nodal structure in the three-dimensional Brillouin zone
(BZ) protected by the chiral symmetry. Topological changes of the line nodes
are demonstrated associated with modification of the tension. The line nodes
projected into two-dimensional BZ form loops which are characterized by the
quantized Zak phases by 0 and $\pi$. With boundaries, edge states are discussed
in relation to the Zak phases and winding numbers. It establishes a bulk-edge
correspondence of the mechanical diamond.


title:
Existence of guided waves due to a lineic perturbation of a 3D periodic
  medium

abstract:
  In this note, we exhibit a three dimensional structure that permits to guide
waves. This structure is obtained by a geometrical perturbation of a 3D
periodic domain that consists of a three dimensional grating of equi-spaced
thin pipes oriented along three orthogonal directions. Homogeneous Neumann
boundary conditions are imposed on the boundary of the domain. The diameter of
the section of the pipes, of order $\epsilon$ \textgreater{} 0, is supposed to
be small. We prove that, for $\epsilon$ small enough, shrinking the section of
one line of the grating by a factor of $\sqrt$ $\mu$ (0 \textless{} $\mu$
\textless{} 1) creates guided modes that propagate along the perturbed line.
Our result relies on the asymptotic analysis (with respect to $\epsilon$) of
the spectrum of the Laplace-Neumann operator in this structure. Indeed, as
$\epsilon$ tends to 0, the domain tends to a periodic graph, and the spectrum
of the associated limit operator can be computed explicitly.


title: Quantum key distribution protocol based on contextuality monogamy

abstract:
  The security of quantum key distribution protocols hinges upon features of
physical systems that are uniquely quantum in nature. We explore the role of
quantumness as qualified by quantum contextuality, in quantum key distribution
schemes. We present a new quantum key distribution protocol whose security
depends uponthe KCBS inequality and contextuality monogamy. We explicitly
calculate the key rate, error rate introduced between Alice-Bob communication
due to the presence of Eve, and the information-gain by Eve. This protocol
provides a new framework for quantum key distribution which has conceptual and
practical advantages over other quantum protocols.


title:
Energy spectrum and critical exponents of the free parafermion $Z_N$
  spin chain

abstract:
  Results are given for the ground state energy and excitation spectrum of a
simple $N$-state $Z_N$ spin chain described by free parafermions. The model is
non-Hermitian for $N \ge 3$ with a real ground state energy and a complex
excitation spectrum. Although having a simpler Hamiltonian than the
superintegrable chiral Potts model, the model is seen to share some properties
with it, e.g., the specific heat exponent $\alpha=1-2/N$ and the anisotropic
correlation length exponents $\nu_\parallel =1$ and $\nu_\perp=2/N$.

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


title: Spin relaxation in a one-dimensional large-spin degenerate Fermi gas

abstract:
  In this work, we study the dynamics of an atomic harmonically trapped
large-spin Fermi gas in one dimension (1D). We investigate the interplay of
different collision processes. Coherent spin oscillations, driven by
spin-changing forward scattering are captured by a mean-field description and
scale linearly with density regardless of the dimension of the system.
Conversely, "incoherent" collision processes which e.g. lead to the damping of
spin oscillations, behave differently. In the usual three-dimensional (3D)
case, the rate of incoherent processes increases faster with density than
mean-field effects, but in 1D it increases slower. This means, that in the 1D
case, incoherent collisions become more important at lower densities. We study
these effects by deriving and integrating a quantum Boltzmann equation. We
demonstrate that the well known fact that in one dimension, interaction-induced
correlations become more dominant at low densities can be observed in
far-from-equilibrium spin dynamics.