title:
Vibration-assisted resonance in photosynthetic excitation energy
  transfer

abstract:
  Understanding how the effectiveness of natural photosynthetic energy
harvesting systems arises from the interplay between quantum coherence and
environmental noise represents a significant challenge for quantum theory.
Recently it has begun to be appreciated that discrete molecular vibrational
modes may play an important role in the dynamics of such systems. As an
alternative to computationally demanding numerical approaches, we present a
microscopic mechanism by which intramolecular vibrations contribute to the
efficiency and directionality of energy transfer. Excited vibrational states
create resonant pathways through the system, supporting fast and efficient
energy transport. Vibrational damping together with the natural downhill
arrangement of molecular energy levels gives intrinsic directionality to the
energy flow. Analytical and numerical results demonstrate a significant
enhancement of the efficiency and directionality of energy transport that can
be directly related to the existence of resonances between vibrational and
excitonic levels.


title: The Structure of Non-Abelian Kinks

abstract:
  We consider a class of integrable quantum field theories in 1+1 dimensions
whose classical equations have kink solutions with internal collective
coordinates that transform under a non-abelian symmetry group. These
generalised sine-Gordon theories have been shown to be related to the world
sheet theory of the string in the AdS/CFT correspondence. We provide a careful
analysis of the boundary conditions at spatial infinity complicated by the fact
that they are defined by actions with a WZ term. We go on to describe the local
and non-local charges carried by the kinks and end by showing that their
structure is perfectly consistent with the exact factorizable S-matrices that
have been proposed to describe these theories.


title:
A new interpretation of the far-infrared - radio correlation and the
  expected breakdown at high redshift

abstract:
  (Abrigded) Observations of galaxies up to z 2 show a tight correlation
between far-infrared and radio continuum emission. We explain the far-infrared
- radio continuum correlation by relating star formation and magnetic field
strength in terms of turbulent magnetic field amplification, where turbulence
is injected by supernova explosions from massive stars. We calculate the
expected amount of turbulence in galaxies based on their star formation rates,
and infer the expected magnetic field strength due to turbulent dynamo
amplification. We estimate the timescales for cosmic ray energy losses via
synchrotron emission, inverse Compton scattering, ionization and bremsstrahlung
emission, probing up to which redshift strong synchrotron emission can be
maintained. We find that the correlation between star formation rate and
magnetic field strength in the local Universe can be understood as a result of
turbulent magnetic field amplification. If the typical gas density in the
interstellar medium increases at high z, we expect an increase of the magnetic
field strength and the radio emission, as indicated by current observations.
Such an increase would imply a modification of the far-infrared - radio
correlation. We expect a breakdown when inverse Compton losses start dominating
over synchrotron emission. For a given star formation surface density, we
calculate the redshift where the breakdown occurs, yielding z (Sigma_SFR/0.0045
M_solar kpc^{-2} yr^{-1})^{1/(6-alpha/2)}. In this relation, the parameter
\alpha describes the evolution of the characteristic ISM density in galaxies as
(1+z)^\alpha. Both the possible raise of the radio emission at high redshift
and the final breakdown of the far-infrared -- radio correlation at a critical
redshift will be probed by the Square Kilometre Array (SKA) and its
pathfinders, while the typical ISM density in galaxies will be probed with
ALMA.


title: Non-negative spectral measures and representations of C*-algebras

abstract:
  Regular normalized W-valued spectral measures on a compact Hausdorff space X
are in one-to-one correspondence with unital *-representations \rho:C(X)\to W,
where W stands for a von Neumann algebra. In this paper we show that for every
compact Hausdorff space X and every von Neumann algebras W_1,W_2 there is a
one-to-one correspondence between unital *-representations \rho:C(X,W_1)\to W_2
and special B(W_1,W_2)-valued measures on X that we call non-negative spectral
measures. Such measures are special cases of non-negative measures that we
introduced in our previous paper in connection with moment problems for
operator polynomials.


title: Higher Spin vs. Renormalization Group Equations

abstract:
  We present a variation of earlier attempts to relate renormalization group
equations to higher spin equations. We work with a scalar field theory in 3
dimensions. In this case we show that the classical renormalization group
equation is a variant of the Vasiliev higher spin equations with Kleinians on
AdS$_4$ for a certain subset of couplings. In the large N limit this
equivalence extends to the quantum theory away from the conformal fixed points.


title: Stable and real-zero polynomials in two variables

abstract:
  For every bivariate polynomial $p(z_1, z_2)$ of bidegree $(n_1, n_2)$, with
$p(0,0)=1$, which has no zeros in the open unit bidisk, we construct a
determinantal representation of the form $$p(z_1,z_2)=\det (I - K Z),$$ where
$Z$ is an $(n_1+n_2)\times(n_1+n_2)$ diagonal matrix with coordinate variables
$z_1$, $z_2$ on the diagonal and $K$ is a contraction. We show that $K$ may be
chosen to be unitary if and only if $p$ is a (unimodular) constant multiple of
its reverse.
  Furthermore, for every bivariate real-zero polynomial $p(x_1, x_2),$ with
$p(0,0)=1$, we provide a construction to build a representation of the form
$$p(x_1,x_2)=\det (I+x_1A_1+x_2A_2),$$ where $A_1$ and $A_2$ are Hermitian
matrices of size equal to the degree of $p$.
  A key component of both constructions is a stable factorization of a positive
semidefinite matrix-valued polynomial in one variable, either on the circle
(trigonometric polynomial) or on the real line (algebraic polynomial).


title: Lateral Gene Transfer, Rearrangement and Reconciliation

abstract:
  Background.
  Models of ancestral gene order reconstruction have progressively integrated
different evolutionary patterns and processes such as unequal gene content,
gene duplications, and implicitly sequence evolution via reconciled gene trees.
In unicellular organisms, these models have so far ignored lateral gene
transfer, even though it can have an important confounding effect on such
models, as well as a rich source of information on the function of genes
through the detection of transfers of entire clusters of genes.
  Result.
  We report an algorithm together with its implementation, DeCoLT, that
reconstructs ancestral genome organization based on reconciled gene trees which
summarize information on sequence evolution, gene origination, duplication,
loss, and lateral transfer. DeCoLT finds in polynomial time the minimum number
of rearrangements, computed as the number of gains and breakages of adjacencies
between pairs of genes. We apply DeCoLT to 1099 gene families from 36
cyanobacteria genomes.
  Conclusion.
  DeCoLT is able to reconstruct adjacencies in 35 ancestral bacterial genomes
with a thousand genes families in a few hours, and detects clusters of
co-transferred genes. As there is no constraint on genome organization,
adjacencies can be generalized to any relationship between genes to reconstruct
ancestral interactions, functions or complexes with the same framework.


title: A Temporal Logic for Hyperproperties

abstract:
  Hyperproperties, as introduced by Clarkson and Schneider, characterize the
correctness of a computer program as a condition on its set of computation
paths. Standard temporal logics can only refer to a single path at a time, and
therefore cannot express many hyperproperties of interest, including
noninterference and other important properties in security and coding theory.
In this paper, we investigate an extension of temporal logic with explicit path
variables. We show that the quantification over paths naturally subsumes other
extensions of temporal logic with operators for information flow and knowledge.
The model checking problem for temporal logic with path quantification is
decidable. For alternation depth 1, the complexity is PSPACE in the length of
the formula and NLOGSPACE in the size of the system, as for linear-time
temporal logic.


title:
Semiparametric Gaussian copula models: Geometry and efficient rank-based
  estimation

abstract:
  We propose, for multivariate Gaussian copula models with unknown margins and
structured correlation matrices, a rank-based, semiparametrically efficient
estimator for the Euclidean copula parameter. This estimator is defined as a
one-step update of a rank-based pilot estimator in the direction of the
efficient influence function, which is calculated explicitly. Moreover,
finite-dimensional algebraic conditions are given that completely characterize
efficiency of the pseudo-likelihood estimator and adaptivity of the model with
respect to the unknown marginal distributions. For correlation matrices
structured according to a factor model, the pseudo-likelihood estimator turns
out to be semiparametrically efficient. On the other hand, for Toeplitz
correlation matrices, the asymptotic relative efficiency of the
pseudo-likelihood estimator can be as low as 20%. These findings are confirmed
by Monte Carlo simulations. We indicate how our results can be extended to
joint regression models.


title:
Millimeter Wave Beamforming for Wireless Backhaul and Access in Small
  Cell Networks

abstract:
  Recently, there has been considerable interest in new tiered network cellular
architectures, which would likely use many more cell sites than found today.
Two major challenges will be i) providing backhaul to all of these cells and
ii) finding efficient techniques to leverage higher frequency bands for mobile
access and backhaul. This paper proposes the use of outdoor millimeter wave
communications for backhaul networking between cells and mobile access within a
cell. To overcome the outdoor impairments found in millimeter wave propagation,
this paper studies beamforming using large arrays. However, such systems will
require narrow beams, increasing sensitivity to movement caused by pole sway
and other environmental concerns. To overcome this, we propose an efficient
beam alignment technique using adaptive subspace sampling and hierarchical beam
codebooks. A wind sway analysis is presented to establish a notion of beam
coherence time. This highlights a previously unexplored tradeoff between array
size and wind-induced movement. Generally, it is not possible to use larger
arrays without risking a corresponding performance loss from wind-induced beam
misalignment. The performance of the proposed alignment technique is analyzed
and compared with other search and alignment methods. The results show
significant performance improvement with reduced search time.


title: How does non-linear dynamics affect the baryon acoustic oscillation?

abstract:
  We study the non-linear behavior of the baryon acoustic oscillation in the
power spectrum and the correlation function by decomposing the dark matter
perturbations into the short- and long-wavelength modes. The evolution of the
dark matter fluctuations can be described as a global coordinate transformation
caused by the long-wavelength displacement vector acting on short-wavelength
matter perturbation undergoing non-linear growth. Using this feature, we
investigate the well known cancellation of the high-$k$ solutions in the
standard perturbation theory. While the standard perturbation theory naturally
satisfies the cancellation of the high-$k$ solutions, some of the recently
proposed improved perturbation theories do not guarantee the cancellation. We
show that this cancellation clarifies the success of the standard perturbation
theory at the 2-loop order in describing the amplitude of the non-linear power
spectrum even at high-$k$ regions.We propose an extension of the standard
2-loop level perturbation theory model of the non-linear power spectrum that
more accurately models the non-linear evolution of the baryon acoustic
oscillation than the standard perturbation theory. The model consists of simple
and intuitive parts: the non-linear evolution of the smoothed power spectrum
without the baryon acoustic oscillations and the non-linear evolution of the
baryon acoustic oscillations due to the large-scale velocity of dark matter and
due to the gravitational attraction between dark matter particles. Our extended
model predicts the smoothing parameter of the baryon acoustic oscillation peak
at $z=0.35$ as $\sim 7.7\ {\rm Mpc}/h$ and describes the small non-linear shift
in the peak position due to the galaxy random motions.


title:
A simple form for the low-x generalized parton distributions in the
  skewed regime

abstract:
  We show that the generalized parton distributions (GPDFs) in the 'skewed' $x
\approx \xi << 1$ regime can be related in a particularly simple way to the
usual diagonal distributions. This follows directly from the Shuvaev transform,
but bypasses a direct evaluation of the poorly convergent double integral which
this relation contains, thus allowing for a more transparent understanding of
the physics involved; it avoids the necessity for any further low-x
approximations for the diagonal partons, as well as permitting a clearer
application to cases when the GPDFs unintegrated over the parton transverse
momentum are required. We consider for illustration the specific examples of
the central exclusive production of a Standard Model Higgs boson, and the
photoproduction of a Upsilon meson at the LHC, and show how a careful
evaluation of the GPDFs, which our simple results allow, is required to
correctly calculate the predicted cross sections.


title:
Finding the Rashba-type spin-splitting from interband scattering in
  quasiparticle interference maps

abstract:
  We have studied the BiCu$_2$/Cu(111) surface alloy using low-temperature
scanning tunneling microscopy and spectroscopy. We observed standing waves
caused by scattering off defects and step edges. Different from previous
studies on similar Rashba-type surfaces, we identified multiple scattering
vectors that originate from various intraband as well as interband scattering
processes. A detailed energy-dependent analysis of the standing-wave patterns
enables a quantitative determination of band dispersions, including the Rashba
splitting. The results are in good agreement with ARPES data and demonstrate
the usefulness of this strategy to determine the band structure of Rashba
systems. The lack of other possible scattering channels will be discussed in
terms of spin conservation and hybridization effects. The results open new
possibilities to study spin-dependent scattering on complex spin-orbit coupled
surfaces.


title: Testing the effects from dark radiation

abstract:
  In this letter, the effects of dark radiation (DR) are tested. Theoretically,
the phase-space analysis method is applied to check whether the model is
consist with the history of our universe which shows positive results.
Observationally, by using the observational data ($SNLS$ (SuperNovae Legacy
Survey), $WMAP9$(Wilkinson Microwave Anisotropy Probe 9 Years Result), $PLANCK$
(Planck First Data Release), $BAO$ (Baryon Acoustic Oscillations), $H(z)$
(Hubble Parameter Data) and $BBN$ (Big Bang Nucleosynthesis)), the dark
radiation is found to have the effect of wiping out the tension between the
$SNLS$ data and the other data in flat $\Lambda CDM$ model. The effects of dark
radiation also make the best fit value of $N_{eff}$ slightly larger than 3.04.


title: Using conditional entropy to identify periodicity

abstract:
  This paper presents a new period finding method based on conditional entropy
that is both efficient and accurate. We demonstrate its applicability on
simulated and real data. We find that it has comparable performance to other
information-based techniques with simulated data but is superior with real
data, both for finding periods and just identifying periodic behaviour. In
particular, it is robust against common aliasing issues found with other
period-finding algorithms.


title:
Electron localization in disordered graphene: multifractal properties of
  the wavefunctions

abstract:
  An analysis of the electron localization properties in doped graphene is
performed by doing a numerical multifractal analysis. By obtaining the
singularity spectrum of a tight-binding model, it is found that the electron
wave functions present a multifractal behavior. Such multifractality is
preserved even for second neighbor interaction, which needs to be taken into
account if a comparison is desired with experimental results. States close to
the Dirac point have a wider multifractal character than those far from this
point as the impurity concentration is increased. The analysis of the results
allows to conclude that in the split-band limit, where impurities act as
vacancies, the system can be well described by a chiral orthogonal symmetry
class, with a singularity spectrum transition approaching freezing as disorder
increases. This also suggests that in doped graphene, localization is in
contrast with the conventional picture of Anderson localization in two
dimensions, showing also that the common belief of the absence of quantum
percolation in two dimensional systems needs to be revised.


title:
Characteristic Sign Change of the Magnetoresistance of Strongly
  Correlated GaAs Two-dimensional Holes

abstract:
  High quality strongly correlated two-dimensional (2D) electron systems at low
temperatures $T\rightarrow 0$ exhibits an apparent metal-to-insulator
transition (MIT) at a large $r_s$ value around 40. We have measured the
magnetoresistance of 2D holes in weak perpendicular magnetic field in the
vicinity of the transition for a series of carrier densities ranging from
$0.2-1.5\times10^{10}$ $cm^{-2}$. The sign of the magnetoresistance is found to
be charge density dependent: in the direction of decreasing density, the sign
changes from being positive to negative across a characteristic value that
coincides with the critical density of MIT.


title: Modulated two-level system : Exact work statistics

abstract:
  We consider an open two-level system driven by a piecewise constant periodic
field and described by a rate equation with Fermi, Bose and Arrhenious rates
respectively. We derive an analytical expression for the generating function
and large deviation function of the work performed by the field and show that a
work fluctuation theorem holds.


title:
Generalizing and Implementing Michael Hirschhorn's Amazing Algorithm for
  Proving Ramanujan-Type Congruences

abstract:
  When Mike Hirschhorn showed us his lovely gem, that gives the
simplest-to-date proof of Ramanujan's famous result that p(11n+6) is divisible
by 11, we realized that his amazing method can be extended, and taught to a
computer, and can prove even deeper identities. We would have done much more if
not for the existence of Silviu Radu's powerful algorithm that handle any
Ramanujan type congruence for any modular form (of a very general type), but it
is still nice to know that in order to prove such simply stated results, that
can be explained to a seven-year-old, one does not need the intimidating
edifice of the "web of modularity", that Ramanujan never mastered, and probably
would not have liked.


title: A class of C*-algebras that are prime but not primitive

abstract:
  We establish necessary and sufficient conditions on a (not necessarily
countable) graph E for the graph C*-algebra C*(E) to be primitive. Along with a
known characterization of the graphs E for which C*(E) is prime, our main
result provides us with a systematic method for easily producing large classes
of (necessarily nonseparable) C*-algebras that are prime but not primitive. We
also compare and contrast our results with similar results for Leavitt path
algebras.


title:
Towards a better insight of RDF triples Ontology-guided Storage system
  abilities

abstract:
  The vision of the Semantic Web is becoming a reality with billions of RDF
triples being distributed over multiple queryable end-points (e.g. Linked
Data). Although there has been a body of work on RDF triples persistent
storage, it seems that, considering reasoning dependent queries, the problem of
providing an efficient, in terms of performance, scalability and data
redundancy, partitioning of the data is still open. In regards to recent data
partitioning studies, it seems reasonable to think that data partitioning
should be guided considering several directions (e.g. ontology, data,
application queries). This paper proposes several contributions: describe an
overview of what a road map for data partitioning for RDF data efficient and
persistent storage should contain, present some preliminary results and
analysis on the particular case of ontology-guided (property hierarchy)
partitioning and finally introduce a set of semantic query rewriting rules to
support querying RDF data needing OWL inferences


title:
Extended Subspace Error Localization for Rate-Adaptive Distributed
  Source Coding

abstract:
  A subspace-based approach for rate-adaptive distributed source coding (DSC)
based on discrete Fourier transform (DFT) codes is developed. Punctured DFT
codes can be used to implement rate-adaptive source coding, however they
perform poorly after even moderate puncturing since the performance of the
subspace error localization degrades severely. The proposed subspace-based
error localization extends and improves the existing one, based on additional
syndrome, and is naturally suitable for rate-adaptive distributed source coding
architecture.


title:
Boundary regularity for viscosity solutions of fully nonlinear elliptic
  equations

abstract:
  We provide regularity results at the boundary for continuous viscosity
solutions to nonconvex fully nonlinear uniformly elliptic equations and
inequalities in Euclidian domains. We show that (i) any solution of two sided
inequalities with Pucci extremal operators is $C^{1,\alpha}$ on the boundary;
(ii) the solution of the Dirichlet problem for fully nonlinear uniformly
elliptic equations is $C^{2,\alpha}$ on the boundary; (iii) corresponding
asymptotic expansions hold. This is an extension to viscosity solutions of the
classical Krylov estimates for smooth solutions.


title: Overdetermined problems for fully nonlinear elliptic equations

abstract:
  We prove that the existence of a solution to a fully nonlinear elliptic
equation in a bounded domain $\Omega$ with an overdetermined boundary condition
prescribing both Dirichlet and Neumann constant data forces the domain $\Omega$
to be a ball. This is a generalization of Serrin's classical result from 1971.


title:
A singularly perturbed Dirichlet problem for the Laplace operator in a
  periodically perforated domain. A functional analytic approach

abstract:
  Let $\Omega$ be a sufficiently regular bounded open connected subset of
$\mathbb{R}^n$ such that $0 \in \Omega$ and that $\mathbb{R}^n \setminus
\mathrm{cl}\Omega$ is connected. Then we take $q_{11},..., q_{nn}\in
]0,+\infty[$ and $p \in Q\equiv \prod_{j=1}^{n}]0,q_{jj}[$. If $\epsilon$ is a
small positive number, then we define the periodically perforated domain
$\mathbb{S}[\Omega_\epsilon]^{-} \equiv \mathbb{R}^n\setminus \cup_{z \in
\mathbb{Z}^n}\mathrm{cl}\bigl(p+\epsilon \Omega +\sum_{j=1}^n
(q_{jj}z_j)e_j\bigr)$, where $\{e_1,...,e_n\}$ is the canonical basis of
$\mathbb{R}^n$. For $\epsilon$ small and positive, we introduce a particular
Dirichlet problem for the Laplace operator in the set
$\mathbb{S}[\Omega_\epsilon]^{-}$. Namely, we consider a Dirichlet condition on
the boundary of the set $p+\epsilon \Omega$, together with a periodicity
condition. Then we show real analytic continuation properties of the solution
and of the corresponding energy integral as functionals of the pair of
$\epsilon$ and of the Dirichlet datum on $p+\epsilon \partial \Omega$, around a
degenerate pair with $\epsilon=0$.


title:
Next generation input-output data format for HEP using Google's protocol
  buffers

abstract:
  We propose a data format for Monte Carlo (MC) events, or any structural data,
including experimental data, in a compact binary form using variable-size
integer encoding as implemented in the Google's Protocol Buffers package. This
approach is implemented in the so-called ProMC library which produces smaller
file sizes for MC records compared to the existing input-output libraries used
in high-energy physics (HEP). Other important features are a separation of
abstract data layouts from concrete programming implementations,
self-description and random access. Data stored in ProMC files can be written,
read and manipulated in a number of programming languages, such C++, Java and
Python.


title:
Nebular Excitation in z~2 Star-forming Galaxies from the SINS and LUCI
  Surveys: The Influence of Shocks and AGN

abstract:
  Based on high-resolution, spatially resolved data of 10 z~2 star-forming
galaxies from the SINS/zC-SINF survey and LUCI data for 12 additional galaxies,
we probe the excitation properties of high-z galaxies and the impact of active
galactic nuclei (AGN), shocks and photoionization. We explore how these
spatially-resolved line ratios can inform our interpretation of integrated
emission line ratios obtained at high redshift. Many of our galaxies fall in
the `composite' region of the z~0 [NII]/Ha versus [OIII]/Hb diagnostic (BPT)
diagram, between star-forming galaxies and those with AGN. Based on our
resolved measurements, we find that some of these galaxies likely host an AGN,
while others appear to be affected by the presence of shocks possibly caused by
an outflow or from enhanced ionization parameter as compared with HII regions
in normal local star-forming galaxies. We find that the Mass-Excitation (MEx)
diagnostic, which separates purely star-forming and AGN hosting local galaxies
in the [OIII]/Hb versus stellar mass plane, does not properly separate z~2
galaxies classified according to the BPT diagram. However, if we shift the
galaxies based on the offset between the local and z~2 mass-metallicity
relation (i.e. to the mass they would have at z~0 with the same metallicity),
we find better agreement between the MEx and BPT diagnostics. Finally, we find
that metallicity calibrations based on [NII]/Ha are more biased by shocks and
AGN at high-z than the [OIII]/Hb/[NII]/Ha calibration.


title: Supersparse Linear Integer Models for Interpretable Classification

abstract:
  Scoring systems are classification models that only require users to add,
subtract and multiply a few meaningful numbers to make a prediction. These
models are often used because they are practical and interpretable. In this
paper, we introduce an off-the-shelf tool to create scoring systems that both
accurate and interpretable, known as a Supersparse Linear Integer Model (SLIM).
SLIM is a discrete optimization problem that minimizes the 0-1 loss to
encourage a high level of accuracy, regularizes the L0-norm to encourage a high
level of sparsity, and constrains coefficients to a set of interpretable
values. We illustrate the practical and interpretable nature of SLIM scoring
systems through applications in medicine and criminology, and show that they
are are accurate and sparse in comparison to state-of-the-art classification
models using numerical experiments.


title:
Invertible extensions of symmetric operators and the corresponding
  generalized resolvents

abstract:
  In this paper we study invertible extensions of a symmetric operator in a
Hilbert space $H$. All such extensions are characterized by a parameter in the
generalized Neumann's formulas. Generalized resolvents, which are generated by
the invertible extensions, are extracted by a boundary condition among all
generalized resolvents in the Shtraus formula.


title:
Cloaking due to anomalous localized resonance in plasmonic structures of
  confocal ellipses

abstract:
  If a core of dielectric material is coated by a plasmonic structure of
negative dielectric material with non-zero loss parameter, then anomalous
localized resonance may occur as the loss parameter tends to zero and the
source outside the structure can be cloaked. It has been proved that the
cloaking due to anomalous localized resonance (CALR) takes place for structures
of concentric disks and the critical radius inside which the sources are
cloaked has been computed. In this paper, it is proved that CALR takes place
for structures of confocal ellipses and the critical elliptic radii are
computed. The method of this paper uses the spectral analysis of the
Neumann-Poincar\'e type operator associated with two interfaces (the boundaries
of the core and the shell).


title:
Speed of sound of a Bose--Einstein condensate with dipole--dipole
  interactions

abstract:
  In the present work the case of a chromium Bose-Einstein condensate is
considered. The model includes not only the presence of the so-called contact
interaction but also a long range and anisotropic dipole-dipole interaction has
been included. Some thermodynamical properties are analyzed. For instance, the
size of the condensate, chemical potential, speed of sound, number of
particles, etc., are deduced. It will be shown that this dipole-dipole
interaction implies the emergence of anisotropy, for example, in the speed of
sound. The possible use of this anisotropy as a tool for the analyze of
dissipative mechanisms, for instance, Landau's criterion for superfluidity,
will be also discussed.


title: Smallness and Comparison Properties for Minimal Dynamical Systems

abstract:
  We introduce the dynamic comparison property for minimal dynamical systems
which has applications to the study of crossed product C*-algebras. We
demonstrate that this property holds for a large class of systems which
includes all examples where the underlying space is finite-dimensional, as well
as for an explicit infinite-dimensional example, showing that the it is
strictly weaker than finite-dimensionality in general.


title:
Crossed Products by Automorphisms with the Tracial Quasi-Rokhlin
  Property

abstract:
  We introduce the tracial quasi-Rokhlin property for an automorphism alpha of
a unital C*-algebra A, which is not assumed to be simple. We show that under
suitable hypotheses, the associated crossed product C*-algebra C*(Z,A,alpha) is
simple, and there is a bijection between the space of tracial states on
C*(Z,A,alpha)$ and the alpha-invariant tracial states on A. We show that, for a
minimal dynamical system (X,h) and a simple, separable, unital C*-algebra A,
the automorphism beta which extends the action of h on C(X) has the tracial
quasi-Rokhlin property, and hence that C*(Z,C(X,A),beta) has the structural
properties described above.


title:
Three-Body Bound State Calculations by Using Three-Dimensional Low
  Momentum Interaction $V_{low-k}$

abstract:
  Three-dimensional (3D) Faddeev integral equations are solved for three-body
(3B) bound state problem without using the partial wave (PW) form of low
momentum two-body (2B) interaction $V_{low-k}$ which is constructed from spin
independent Malfliet-Tjon V (MT-V) potential. The dependence of 3B binding
energy on the cutoff momentum of $V_{low-k}$ is investigated for a wide range
of $\Lambda$ from $1.0$ to $7.0\, fm^{-1}$. The properties of Faddeev
components and 3B wave function are displayed and the effect of number of grid
points for momentum and angle variables on the accuracy and the stability of
numerical results is studied by calculation of the expectation value of total
Hamiltonian.


title:
Supplement to "Markov Chain Monte Carlo Based on Deterministic
  Transformations"

abstract:
  This is a supplement to the article "Markov Chain Monte Carlo Based on
Deterministic Transformations" available at http://arxiv.org/abs/1106.5850


title:
Local convertibility and the quantum simulation of edge states in
  many-body systems

abstract:
  In some many-body systems, certain ground state entanglement (Renyi)
entropies increase even as the correlation length decreases. This entanglement
non-monotonicity is a potential indicator of non-classicality. In this work we
demonstrate that such a phenomenon, known as non-local convertibility, is due
to the edge state (de)construction occurring in the system. To this end, we
employ the example of the Ising chain, displaying an order-disorder quantum
phase transitions. Employing both analytical and numerical methods, we compute
entanglement entropies for various system bipartitions (A|B) and consider
ground states with and without Majorana edge states. We find that the thermal
ground states, enjoying the Hamiltonian symmetries, show non-local
convertibility if either A or B are smaller than, or of the order of, the
correlation length. In contrast, the ordered (symmetry breaking) ground state
is always locally convertible. The edge states behavior explains all these
results and could disclose a paradigm to understand local convertibility in
other quantum phases of matter. The connection we establish between
convertibility and non-local, quantum correlations provides a clear criterion
of which features a universal quantum simulator should possess to outperform a
classical machine.

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


title: Query Complexity of Approximate Nash Equilibria

abstract:
  We study the query complexity of approximate notions of Nash equilibrium in
games with a large number of players $n$. Our main result states that for
$n$-player binary-action games and for constant $\varepsilon$, the query
complexity of an $\varepsilon$-well-supported Nash equilibrium is exponential
in $n$. One of the consequences of this result is an exponential lower bound on
the rate of convergence of adaptive dynamics to approxiamte Nash equilibrium.


title: Moduli destabilization via gravitational collapse

abstract:
  We examine the interplay between gravitational collapse and moduli stability
in the context of black hole formation. We perform numerical simulations of the
collapse using the double null formalism and show that the very dense regions
one expects to find in the process of black hole formation are able to
destabilize the volume modulus. We establish that the effects of the
destabilization will be visible to an observer at infinity, opening up a window
to a region in spacetime where standard model's couplings and masses can differ
significantly from their background values.


title: Ricci flow on surfaces with conic singularities

abstract:
  We establish the short-time existence of the Ricci flow on surfaces with a
finite number of conic points, all with cone angle between 0 and $2\pi$, where
the cone angles remain fixed or change in some smooth prescribed way. For the
angle-preserving flow we prove long-time existence and convergence. When the
Troyanov angle condition is satisfied (equivalently, when the data is
logarithmically K-stable), the flow converges to the unique constant curvature
metric with the given cone angles; if this condition is not satisfied, the flow
converges subsequentially to a soliton. This is the one-dimensional version of
the Hamilton--Tian conjecture.


title:
Transmission-phase measurement of the 0.7 anomaly in a quantum point
  contact

abstract:
  We measure the transmission phase of a quantum point contact (QPC) at a low
carrier density in which electron interaction is expected to play an important
role and anomalous behaviors are observed. In the first conductance plateau,
the transmission phase shifts monotonically as the carrier density is decreased
by the gate voltage. When the conductance starts to decrease, in what is often
called the 0.7 regime, the phase exhibits an anomalous increase compared with
the noninteracting model. The observation implies an increase in the wave
vector as the carrier density is decreased, suggesting a transition to a
spin-incoherent Luttinger liquid.


title:
Neutrino-cooled Accretion Model with Magnetic Coupling for X-ray Flares
  in GRBs

abstract:
  The neutrino-cooled accretion disk, which was proposed to work as the central
engine of gamma-ray bursts, encounters difficulty in interpreting the X-ray
flares after the prompt gamma-ray emission. In this paper, the magnetic
coupling between the inner disk and the central black hole is taken into
consideration. For mass accretion rates around $0.001 \sim 0.1 M_{\sun}
s^{-1}$, our results show that the luminosity of neutrino annihilation can be
significantly enhanced due to the coupling effects. As a consequence, after the
gamma-ray emission, a remnant disk with mass $M_{disk} \la 0.5 M_{\sun}$ may
power most of the observed X-ray flares with the rest frame duration less than
100 seconds. In addition, a comparison between the magnetic coupling process
and the Blandford-Znajek mechanism is shown on the extraction of black hole
rotational energy.


title: Spin-current Seebeck effect in quantum dot systems

abstract:
  We first bring up the concept of spin-current Seebeck effect based on a
recent experiment [Nat. Phys. {\bf 8}, 313 (2012)], and investigate the
spin-current Seebeck effect in quantum dot (QD) systems. Our results show that
the spin-current Seebeck coefficient $S$ is sensitive to different polarization
states of QD, and therefore can be used to detect the polarization state of QD
and monitor the transitions between different polarization states of QD. The
intradot Coulomb interaction can greatly enhance the $S$ due to the stronger
polarization of QD. By using the parameters for a typical QD, we demonstrate
that the maximum $S$ can be enhanced by a factor of 80. On the other hand, for
a QD whose Coulomb interaction is negligible, we show that one can still obtain
a large $S$ by applying an external magnetic field.


title:
Lensing Simulation and Power Spectrum Estimation for High Resolution CMB
  Polarization Maps

abstract:
  We present efficient algorithms for CMB lensing simulation and power spectrum
es- timation for flat-sky CMB polarization maps. We build a pure B-mode
estimator to remedy E to B leakage due to partial sky coverage. We show that
our estimators are unbiased, and consistent with the projected errors. We
demonstrate our algorithm using simulated observations of small sky patches
with realistic noise and weights for upcoming CMB polarization experiments.


title: Azimuthal Dependence of DIS with Spin-1 Target

abstract:
  We study DIS with a spin-1 hadron or a nucleus polarized in arbitrary
direction. The differential cross-section in this case will have an azimuthal
dependence. We derive the dependence by including contributions from twist-2-
and twist-3 QCD operators. The twist-3 contribution is computed at tree-level.
A spin-1 hadron or nucleus can have nonzero tensor polarization. We find that
all structure functions related to the tensor-polarization of the initial
hadron can be extracted by study the azimuthal dependence. A nonzero result of
the structure functions of a nucleus from experiment will indicate nontrivial
inner structure of the nucleus.


title:
Thermophysical properties of hydrogen-helium mixtures: Re-examination of
  the mixing rules via quantum molecular dynamics simulations

abstract:
  Thermophysical properties of hydrogen, helium, and hydrogen-helium mixtures
have been investigated in the warm dense matter regime at electron number
densities ranging from $6.02\times10^{29}\sim2.41\times10^{30}$/m$^{3}$ and
temperatures from 4000 to 20000 K via quantum molecular dynamics simulations.
We focus on the dynamical properties such as the equation of states, diffusion
coefficients, and viscosity. Mixing rules (density matching, pressure matching,
and binary ionic mixing rules) have been validated by checking composite
properties of pure species against that of the fully interacting mixture
derived from QMD simulations. These mixing rules reproduce pressures within 10%
accuracy, while it is 75% and 50% for the diffusion and viscosity,
respectively. Binary ionic mixing rule moves the results into better agreement.
Predictions from one component plasma model are also provided and discussed.

categories: cond-mat.mtrl-sci cond-mat.stat-mech physics.plasm-ph physics.space-ph


title:
Implementation of an impedance-matched \Lambda system by dressed-state
  engineering

abstract:
  In one-dimensional optical setups, light-matter interaction is drastically
enhanced by the interference between the incident and scattered fields.
Particularly, in the impedance-matched \Lambda-type three-level systems, a
single photon deterministically induces the Raman transition and switches the
electronic state of the system. Here we show that such a \Lambda system can be
implemented by using dressed states of a driven superconducting qubit and a
resonator. The input microwave photons are perfectly absorbed and are
down-converted into other frequency modes in the same waveguide. The proposed
setup is applicable to single-photon detection in the microwave domain.


title:
Topological Performance Measures as Surrogates for Physical Flow Models
  for Risk and Vulnerability Analysis for Electric Power Systems

abstract:
  Critical infrastructure systems must be both robust and resilient in order to
ensure the functioning of society. To improve the performance of such systems,
we often use risk and vulnerability analysis to find and address system
weaknesses. A critical component of such analyses is the ability to accurately
determine the negative consequences of various types of failures in the system.
Numerous mathematical and simulation models exist which can be used to this
end. However, there are relatively few studies comparing the implications of
using different modeling approaches in the context of comprehensive risk
analysis of critical infrastructures. Thus in this paper, we suggest a
classification of these models, which span from simple topologically-oriented
models to advanced physical flow-based models. Here, we focus on electric power
systems and present a study aimed at understanding the tradeoffs between
simplicity and fidelity in models used in the context of risk analysis.
Specifically, the purpose of this paper is to compare performances measures
achieved with a spectrum of approaches typically used for risk and
vulnerability analysis of electric power systems and evaluate if more
simplified topological measures can be combined using statistical methods to be
used as a surrogate for physical flow models. The results of our work provide
guidance as to appropriate models or combination of models to use when
analyzing large-scale critical infrastructure systems, where simulation times
quickly become insurmountable when using more advanced models, severely
limiting the extent of analyses that can be performed.


title: Poly-Bernoulli polynomials arising from umbral calculus

abstract:
  In this paper, we give some recurrence formula and new and interesting
identities for the poly-Bernoulli numbers and polynomials which are derived
from umbral calculus.


title: Quasicrystals -- The impact of N.G. de Bruijn

abstract:
  In this paper we put the work of Professor N.G. de Bruijn on quasicrystals in
historical context. After briefly discussing what went before, we shall review
de Bruijn's work together with recent related theoretical and experimental
developments. We conclude with a discussion of Yang-Baxter integrable models on
Penrose tilings, for which essential use of de Bruijn's work has been made.

categories: math-ph cond-mat.stat-mech math.HO math.MP physics.hist-ph


title:
Hi Shells and Supershells in the I-GALFA Hi 21-cm Line Survey: I.
  Fast-Expanding Hi Shells Associated with Supernova Remnants

abstract:
  We search for fast-expanding Hi shells associated with Galactic supernova
remnants (SNRs) in the longitude range l \approx 32\arcdeg to 77\arcdeg using
21-cm line data from the Inner-Galaxy Arecibo L-band Feed Array (I-GALFA) Hi
survey. Among the 39 known Galactic SNRs in this region, we find such Hi shells
in four SNRs: W44, G54.4-0.3, W51C, and CTB 80. All four were previously
identified in low-resolution surveys, and three of those (excluding G54.4-0.3)
were previously studied with the Arecibo telescope. A remarkable new result,
however, is the detection of Hi emission at both very high positive and
negative velocities in W44 from the receding and approaching parts of the Hi
expanding shell, respectively. This is the first detection of both sides of an
expanding shell associated with an SNR in Hi 21-cm emission. The
high-resolution I-GALFA survey data also reveal a prominent expanding Hi shell
with high circular symmetry associated with G54.4-0.3. We explore the physical
characteristics of four SNRs and discuss what differentiates them from other
SNRs in the survey area. We conclude that these four SNRs are likely the
remnants of core-collapse supernovae interacting with a relatively dense (>~1
cm^-3) ambient medium, and we discuss the visibility of SNRs in the Hi 21-cm
line.


title:
Observation of three-state dressed states in circuit quantum
  electrodynamics

abstract:
  We have investigated the microwave response of a transmon qubit coupled
directly to a transmission line. In a transmon qubit, owing to its weak
anharmonicity, a single driving field may generate dressed states involving
more than two bare states. We confirmed the formation of three-state dressed
states by observing all of the six associated Rabi sidebands, which appear as
either amplification or attenuation of the probe field. The experimental
results are reproduced with good precision by a theoretical model incorporating
the radiative coupling between the qubit and the microwave.


title:
Renormalization of Higher Derivative Quantum Gravity Coupled to a Scalar
  with Shift Symmetry

abstract:
  It has been suggested that higher-derivative gravity theories coupled to a
scalar field with shift symmetry may be an important candidate for a quantum
gravity. We show that this class of gravity theories are renormalizable in D =
3 and 4 dimensions.


title: Periodic Billiards in Isosceles Triangles

abstract:
  Any periodic trajectory on an isosceles triangle gives rise to a periodic
trajectory on a right triangle obtained by identifying the halves of the
original triangle. We examine the relationship between periodic trajectories on
isosceles triangles and the trajectories on right triangles obtained in this
manner, and the consequences of this relationship for the existence of stable
trajectories on isosceles triangles and the properties of their orbit tiles.


title: Temporal fluctuation scaling in nonstationary counting processes

abstract:
  The fluctuation scaling law has universally been observed in a wide variety
of phenomena. For counting processes describing the number of events occurred
during time intervals, it is expressed as a power function relationship between
the variance and the mean of the event count per unit time, the characteristic
exponent of which is obtained theoretically in the limit of long duration of
counting windows. Here I show that the scaling law effectively appears even in
a short timescale in which only a few events occur. Consequently, the counting
statistics of nonstationary event sequences are shown to exhibit the scaling
law as well as the dynamics at temporal resolution of this timescale. I also
propose a method to extract in a systematic manner the characteristic scaling
exponent from nonstationary data.


title:
Flow and Tilt-Induced Orientation of the Moving Vortex Lattice in
  Amorphous NbGe Superconducting Thin Films

abstract:
  The orientation and deformation of moving vortex lattices in the flux-flow
state have been investigated in amorphous superconducting NbGe thin films.
Employing a mode-locking technique, we detect how moving lattices deform and
their orientation changes as a magnetic field is tilted from normal to the film
surface. For high tilt angles the lattice orientation is aligned parallely with
the tilt direction. Meanwhile for low tilt angles the lattice orientation
depends on the vortex velocity and a velocity-induced reorientation occurs. The
characteristic velocity for the reorientation varies remarkably as the moving
lattices deform. The observed features are consistent with an extended
bond-fluctuation theory, revealing that the anisotropic shaking vortex motion
is essential for determining the orientation of moving vortex lattices.


title: Conformal field theory of dipolar SLE(4) with mixed boundary condition

abstract:
  We develop a version of dipolar conformal field theory in a simply connected
domain with the Dirichlet-Neumann boundary condition and central charge one. We
prove that all correlation functions of the fields in the OPE family of
Gaussian free field with a certain boundary value are martingale-observables
for dipolar SLE(4).


title:
Estimation of solar zenith passage on the Earth's surface by a simple
  harmonic motion

abstract:
  The kinematics of the Solar zenith passage on the Earth was shown as a simple
harmonic motion. This analytical model used the uniform circular motion to
describe the Earth's rotation relative to its axis and relative to the Sun,
also this model considered the sunlight beams parallel and constant the
obliquity of the ecliptic. We made a contrast between some data taken from of
the software Stellarium 0.12.1 and the model, we obtained an uncertainty
$\Delta t=1d$; this result allow to project the model as an astronomical
context conducive to develop the kinematics of simple harmonic motion.


title: Pretzel knots with L-space surgeries

abstract:
  A rational homology sphere whose Heegaard Floer homology is the same as that
of a lens space is called an L-space. We classify pretzel knots with any number
of tangles which admit L-space surgeries. This rests on Gabai's classification
of fibered pretzel links.


title: Generalized String Topology and Derived Koszul Duality

abstract:
  The generalized string topology construction of Gruher and Salvatore assigns
to any bundle of $E_n$-algebras $A$ over a closed oriented manifold $M$ a
collection of intersection-type operations on the homology of the total space.
These operations are realized by an $H_n$-ring structure on the Thom spectrum
$A^{-TM}$ under the Thom isomorphism. We rigidify and extend this construction
to a functor connecting the homotopy theory of spaces and spectra parametrized
by $M$ to the homotopy theory of module spectra over the
Atiyah-Milnor-Spanier-Whitehead dual $M^{-TM} \simeq \bbD M$. Then, using an
$\infty$-categorical version of Morita theory, we give an alternative
description of our construction in terms of the derived Koszul duality (alias
bar-cobar duality) between $\Sigma^\infty_+ \Omega M$ and $\bbD M$.


title: A Survey on Metric Learning for Feature Vectors and Structured Data

abstract:
  The need for appropriate ways to measure the distance or similarity between
data is ubiquitous in machine learning, pattern recognition and data mining,
but handcrafting such good metrics for specific problems is generally
difficult. This has led to the emergence of metric learning, which aims at
automatically learning a metric from data and has attracted a lot of interest
in machine learning and related fields for the past ten years. This survey
paper proposes a systematic review of the metric learning literature,
highlighting the pros and cons of each approach. We pay particular attention to
Mahalanobis distance metric learning, a well-studied and successful framework,
but additionally present a wide range of methods that have recently emerged as
powerful alternatives, including nonlinear metric learning, similarity learning
and local metric learning. Recent trends and extensions, such as
semi-supervised metric learning, metric learning for histogram data and the
derivation of generalization guarantees, are also covered. Finally, this survey
addresses metric learning for structured data, in particular edit distance
learning, and attempts to give an overview of the remaining challenges in
metric learning for the years to come.


title: The two-handed tile assembly model is not intrinsically universal

abstract:
  The well-studied Two-Handed Tile Assembly Model (2HAM) is a model of tile
assembly in which pairs of large assemblies can bind, or self-assemble,
together. In order to bind, two assemblies must have matching glues that can
simultaneously touch each other, and stick together with strength that is at
least the temperature $\tau$, where $\tau$ is some fixed positive integer. We
ask whether the 2HAM is intrinsically universal, in other words we ask: is
there a single universal 2HAM tile set $U$ which can be used to simulate any
instance of the model? Our main result is a negative answer to this question.
We show that for all $\tau' < \tau$, each temperature-$\tau'$ 2HAM tile system
does not simulate at least one temperature-$\tau$ 2HAM tile system. This
impossibility result proves that the 2HAM is not intrinsically universal, in
stark contrast to the simpler (single-tile addition only) abstract Tile
Assembly Model which is intrinsically universal ("The tile assembly model is
intrinsically universal", FOCS 2012). However, on the positive side, we prove
that, for every fixed temperature $\tau \geq 2$, temperature-$\tau$ 2HAM tile
systems are indeed intrinsically universal: in other words, for each $\tau$
there is a single universal 2HAM tile set $U$ that, when appropriately
initialized, is capable of simulating the behavior of any temperature-$\tau$
2HAM tile system. As a corollary of these results we find an infinite set of
infinite hierarchies of 2HAM systems with strictly increasing simulation power
within each hierarchy. Finally, we show that for each $\tau$, there is a
temperature-$\tau$ 2HAM system that simultaneously simulates all
temperature-$\tau$ 2HAM systems.


title:
Plasma Nanoscience: from Nano-Solids in Plasmas to Nano-Plasmas in
  Solids

abstract:
  The unique plasma-specific features and physical phenomena in the
organization of nanoscale solid-state systems in a broad range of elemental
composition, structure, and dimensionality are critically reviewed. These
effects lead to the possibility to localize and control energy and matter at
nanoscales and to produce self-organized nano-solids with highly unusual and
superior properties. A unifying conceptual framework based on the control of
production, transport, and self-organization of precursor species is introduced
and a variety of plasma-specific non-equilibrium and kinetics-driven phenomena
across the many temporal and spatial scales is explained. When the plasma is
localized to micrometer and nanometer dimensions, new emergent phenomena arise.
The examples range from semiconducting quantum dots and nanowires, chirality
control of single-walled carbon nanotubes, ultra-fine manipulation of
graphenes, nano-diamond, and organic matter, to nano-plasma effects and
nano-plasmas of different states of matter.

categories: physics.plasm-ph cond-mat.mes-hall cond-mat.mtrl-sci physics.bio-ph physics.comp-ph


title: Spinodal decomposition in homogeneous and isotropic turbulence

abstract:
  We study the competition between domain coarsening in a symmetric binary
mixtures below the critical temperature and turbulent fluctuations. We find
that the coarsening process is arrested in presence of turbulence. The physics
of the process shares remarkable similarities with the behaviour of diluted
turbulent emulsions and the arrest length scale can be estimated with an
argument similar to the one proposed by Kolmogorov and Hinze for the maximal
stability diameter of droplets in turbulence. Although in the absence of flow
the microscopic diffusion constant is negative, turbulence does effectively
arrest the inverse cascade of concentration fluctuations by making the low
wavelength diffusion constant positive for scales above the Hinze length.


title: Unitarity Constraints in the standard model with a singlet scalar field

abstract:
  Motivated by the discovery of a new scalar field and amelioration of the
electroweak vacuum stability ascribed to a singlet scalar field embedded in the
standard model (SM), we examine the implication of the perturbative unitarity
in the SM with a singlet scalar field. Taking into account the full
contributions to the scattering amplitudes, we derive unitarity conditions on
the scattering matrix which can be translated into bounds on the masses of the
scalar fields. In the case that the singlet scalar field develops vacuum
expectation value (VEV), we get the upper bound on the singlet scalar mass
varying with the mixing between the singlet and Higgs scalars. On the other
hand, the mass of the Higgs scalar can be constrained by the unitarity
condition in the case that the VEV of the singlet scalar is not generated.
Applying the upper bound on the Higgs mass to the scenario of the unitarized
Higgs inflation, we discuss how the unitarity condition can constrain the Higgs
inflation. The singlet scalar mass is not constrained by the unitarity itself
when we impose Z_2 in the model because of no mixing with the Higgs scalar.
But, regarding the singlet scalar field as a cold dark matter candidate, we
derive upper bound on the singlet scalar mass by combining the observed relic
abundance with the unitarity condition.


title: On the spectral distribution of large weighted random regular graphs

abstract:
  McKay proved that the limiting spectral measures of the ensembles of
$d$-regular graphs with $N$ vertices converge to Kesten's measure as
$N\to\infty$. In this paper we explore the case of weighted graphs. More
precisely, given a large $d$-regular graph we assign random weights, drawn from
some distribution $\mathcal{W}$, to its edges. We study the relationship
between $\mathcal{W}$ and the associated limiting spectral distribution
obtained by averaging over the weighted graphs. Among other results, we
establish the existence of a unique `eigendistribution', i.e., a weight
distribution $\mathcal{W}$ such that the associated limiting spectral
distribution is a rescaling of $\mathcal{W}$. Initial investigations suggested
that the eigendistribution was the semi-circle distribution, which by Wigner's
Law is the limiting spectral measure for real symmetric matrices. We prove this
is not the case, though the deviation between the eigendistribution and the
semi-circular density is small (the first seven moments agree, and the
difference in each higher moment is $O(1/d^2)$). Our analysis uses
combinatorial results about closed acyclic walks in large trees, which may be
of independent interest.


title: The Meaning of Probability of Default for Asset-backed Loans

abstract:
  The authors examine the concept of probability of default for asset-backed
loans. In contrast to unsecured loans it is shown that probability of default
can be defined as either a measure of the likelihood of the borrower failing to
make required payments, or as the likelihood of an insufficiency of collateral
value on foreclosure. Assuming expected loss is identical under either
definition, this implies a corresponding pair of definitions for loss given
default. Industry treatment of probability of default for asset-backed loans
appears to inconsistently blend the two types of definition.
  The authors develop a mathematical treatment of asset-backed loans which
consistently applies each type of definition in a framework to produce the same
expected loss and allows translation between the two frameworks.


title:
Earliest Stages of Protocluster Formation: Substructure and Kinematics
  of Starless Cores in Orion

abstract:
  We study the structure and kinematics of nine 0.1 pc-scale cores in Orion
with the IRAM 30-m telescope and at higher resolution eight of the cores with
CARMA, using CS(2-1) as the main tracer. The single-dish moment zero maps of
the starless cores show single structures with central column densities ranging
from 7 to 42 times 10^23 cm^-2 and LTE masses from 20 solar masses to 154 solar
masses. However, at the higher CARMA resolution (5 arcsec), all of the cores
except one fragment into 3 - 5 components. The number of fragments is small
compared to that found in some turbulent fragmentation models, although
inclusion of magnetic fields may reduce the predicted fragment number and
improve the model agreement. This result demonstrates that fragmentation from
parsec-scale molecular clouds to sub-parsec cores continues to take place
inside the starless cores. The starless cores and their fragments are embedded
in larger filamentary structures, which likely played a role in the core
formation and fragmentation. Most cores show clear velocity gradients, with
magnitudes ranging from 1.7 to 14.3 km/s/pc. We modeled one of them in detail,
and found that its spectra are best explained by a converging flow along a
filament toward the core center; the gradients in other cores may be modeled
similarly. We infer a mass inflow rate of ~ 2 x 10^{-3} Msolar/yr, which is in
principle high enough to overcome radiation pressure and allow for massive star
formation. However, the core contains multiple fragments, and it is unclear
whether the rapid inflow would feed the growth of primarily a single massive
star or a cluster of lower mass objects. We conclude that fast, supersonic
converging flow along filaments play an important role in massive star and
cluster formation.


title: Demixing in symmetric supersolid mixtures

abstract:
  The droplet crystal phase of a symmetric binary mixture of Rydberg-blockaded
dipolar Bose gases is studied by computer simulation. At high temperature each
droplet comprises on average equal numbers of particles of either component,
but the two components demix below the supersolid transition temperature, i.e.,
droplets mostly consist of particles of one component. Droplets consisting of
the same component will also favor clustering. Demixing is driven by quantum
tunnelling of particles across droplets over the system, and does not take
place in a non-superfluid crystal. This effect should be easily detectable in a
cold gas experiment.


title:
Building the Chessboard-like Supramolecular Structure on Au (111)
  Surfaces

abstract:
  We investigate an anthracene derivative, 3(5)-(9-anthryl) pyrazole (ANP),
self-assembled on the Au (111) surface by means of scanning tunneling
microscopy (STM) and density functional theory (DFT) calculations. A
chessboard-like network structure composed of ANP molecules is found, covering
the whole Au (111) substrate. Our STM results and DFT calculations reveal that
the formation of chessboard-like networks originates from a basic unit cell, a
tetramer structure, which is formed by four ANP molecules connected through
C-H-N hydrogen-bonds. The hydrogen bonds inside each tetramer and the molecular
adsorption interaction are fundamentally important in providing a driving force
for formation of the supramolecular networks.


title:
Pulsar Timing Residuals Induced by Gravitational Waves from Single
  Non-evolving Supermassive Black Hole Binaries with Elliptical Orbits

abstract:
  The pulsar timing residuals induced by gravitational waves from non-evolving
single binary sources with general elliptical orbits will be analyzed. For
different orbital eccentricities, the timing residuals present different
properties. The standard deviations of the timing residuals induced by a fixed
gravitational wave source will be calculated for different values of the
eccentricity. We will also analyze the timing residuals of PSR J0437-4715
induced by one of the best known single gravitational wave sources, the
supermassive black hole binary in the blazar OJ287.


title:
Particle Acceleration during Magnetorotational Instability in a
  Collisionless Accretion Disk

abstract:
  Particle acceleration during the magnetorotational instability (MRI) in a
collisionless accretion disk was investigated by using a particle-in-cell (PIC)
simulation. We discuss the important role that magnetic reconnection plays not
only on the saturation of MRI but also on the relativistic particle generation.
The plasma pressure anisotropy of $p_{\perp} > p_{\para}$ induced by the action
of MRI dynamo leads to rapid growth in magnetic reconnection, resulting in the
fast generation of nonthermal particles with a hard power-law spectrum. This
efficient particle acceleration mechanism involved in a collisionless accretion
disk may be a possible model to explain the origin of high energy particles
observed around massive black holes.


title: HMFcalc: An Online Tool for Calculating Dark Matter Halo Mass Functions

abstract:
  The dark matter halo mass function (HMF) is a characteristic property of
cosmological structure formation models, quantifying the number density of dark
matter haloes per unit mass in the Universe. A key goal of current and planned
large galaxy surveys is to measure the HMF and to use it to test theories of
dark matter and dark energy. We present a new web application for calculating
the HMF -- the frontend HMFcalc and the engine hmf. HMFcalc has been designed
to be flexible, efficient and easy to use, providing observational and
theoretical astronomers alike with the means to explore standard functional
forms of the HMF or to tailor their own. We outline the theoretical background
needed to compute the HMF, we show how it has been implemented in hmf, and
finally we provide worked examples that illustrate HMFcalc's versatility as an
analysis tool.


title: Power Spectrum with Auxiliary Fields in de Sitter Space

abstract:
  We use the auxiliary fields and (excited-) de Sitter solutions to study the
standard power spectrum of primordial fluctuations of a scalar field in the
early universe. The auxiliary fields are the negative norm solutions of the
field equation and as it is shown, with a fixed boundary condition, utilizing
these states results in a finite power spectrum without any infinity. The power
spectrum is determined by the de Sitter solutions up to some corrections and
the space-time symmetry is not broken in this point of view. The modulation to
the power spectrum is of order $ (\frac{H}{\Lambda})^{2} $, where $ H $ is the
Hubble parameter and $ \Lambda $ is the energy scale, e.g., Planck scale.


title: First observation of the decay $B_{c}^{+}\to J/\psi K^+$

abstract:
  The decay $B_c^+\to J/\psi K^+$ is observed for the first time using a data
sample, corresponding to an integrated luminosity of 1.0 ${\,fb}^{-1}$,
collected by the LHCb experiment in $pp$ collisions at a centre-of-mass energy
of $7\mathrm{\,Te\kern -0.1em V}$. A yield of $46\pm12$ events is reported,
with a significance of 5.0 standard deviations. The ratio of the branching
fraction of $B_c^+\to J/\psi K^+$ to that of $B_c^+\to J/\psi\pi^+$ is measured
to be $0.069\pm0.019\pm0.005$, where the first uncertainty is statistical and
the second is systematic.


title:
Disformal invariance of second order tensor-scalar theories: framing the
  Horndeski action

abstract:
  The Horndeski action is the most general one involving a metric and a scalar
field that leads to second order field equations in four dimensions. Being the
natural extension of the well known Scalar-Tensor theories, its structure and
properties are worth analysing along the experience accumulated in the latter
context. Here we argue that disformal transformations play, for the Horndeski
theory, a similar role to that of conformal transformations for Scalar-Tensor
theories a l`a Brans-Dicke. We identify the most general transformation
preserving second order field equations and discuss the issue of viable frames
for this kind of theories, in particular the possibility to cast the action in
the so called Einstein frame. Finally, we investigate the physical equivalence
of such frames and their reciprocal relationship.


title: Baryonia and near-threshold enhancements

abstract:
  The baryon-antibaryon spectrum consisting of strange, charm and bottom quarks
is studied in the color flux-tube model with a multi-body confinement
interaction. Numerical results indicate that many low-spin baryon-antibaryon
states can form compact hexaquark states and are stable against the decay into
a baryon and an antibaryon. The multi-body confinement interaction as a binding
mechanism plays an important role in the formation of the states. They can be
searched in the $e^+e^-$ annihilation and charmonium or bottomonium decay if
they really exist. The newly reported states, X(1835), X(2370), Y(2175),
Y(4360) and Y_b(10890), may be interpreted as $N\bar{N}$, $\Delta\bar{\Delta}$,
$\Lambda\bar{\Lambda}$, $\Lambda_c\bar{\Lambda}_c$ and
$\Lambda_b\bar{\Lambda}_b$ states, respectively.


title: A Novel Active Contour Model for Texture Segmentation

abstract:
  Texture is intuitively defined as a repeated arrangement of a basic pattern
or object in an image. There is no mathematical definition of a texture though.
The human visual system is able to identify and segment different textures in a
given image. Automating this task for a computer is far from trivial. There are
three major components of any texture segmentation algorithm: (a) The features
used to represent a texture, (b) the metric induced on this representation
space and (c) the clustering algorithm that runs over these features in order
to segment a given image into different textures. In this paper, we propose an
active contour based novel unsupervised algorithm for texture segmentation. We
use intensity covariance matrices of regions as the defining feature of
textures and find regions that have the most inter-region dissimilar covariance
matrices using active contours. Since covariance matrices are symmetric
positive definite, we use geodesic distance defined on the manifold of
symmetric positive definite matrices PD(n) as a measure of dissimlarity between
such matrices. We demonstrate performance of our algorithm on both artificial
and real texture images.


title:
The role of orbital order in the stabilization of the $(\pi,0)$ ordered
  magnetic state in a minimal two-band model for iron pnictides

abstract:
  Spin wave excitations and stability of the ($\pi,0$) ordered magnetic state
are investigated in a minimal two-band itinerant-electron model for iron
pnictides. Presence of hopping anisotropy generates a strong ferro-orbital
order in the $d_{xz}$ and $d_{yz}$ Fe orbitals. The orbital order sign is as
observed in experiments. The induced ferro-orbital order strongly enhances the
spin wave energy scale and stabilizes the magnetic state by optimizing the
strength of the emergent AF and F spin couplings through optimal band fillings
in the two orbitals. The calculated spin-wave dispersion is in quantitative
agreement with neutron scattering measurements. Finite inter-orbital Hund's
coupling is shown to further enhance the spin wave energies state by coupling
the two magnetic sub-systems. A more realistic two-band model with less hopping
anisotropy is also considered which yields not only the circular hole pockets,
also correct ferro-orbital order and emergent F spin coupling.


title: Min-Cost Flow Duality in Planar Networks

abstract:
  In this paper we study the min-cost flow problem in planar networks. We start
with the min-cost flow problem and apply two transformations, one is based on
geometric duality of planar graphs and the other on linear programming duality.
The result is a min-cost flow problem in a related planar network whose balance
constraints are defined by the costs of the original problem and whose costs
are defined by the capacities of the original problem. We use this
transformation to show an O(n log^2 n) time algorithm for the min-cost flow
problem in an n-vertex outerplanar network.


title:
MITHYS: Mind The Hand You Shake - Protecting mobile devices from SSL
  usage vulnerabilities

abstract:
  Recent studies have shown that a significant number of mobile applications,
often handling sensitive data such as bank accounts and login credentials,
suffers from SSL vulnerabilities. Most of the time, these vulnerabilities are
due to improper use of the SSL protocol (in particular, in its \emph{handshake}
phase), resulting in applications exposed to man-in-the-middle attacks. In this
paper, we present MITHYS, a system able to: (i) detect applications vulnerable
to man-in-the-middle attacks, and (ii) protect them against these attacks. We
demonstrate the feasibility of our proposal by means of a prototype
implementation in Android, named MITHYSApp. A thorough set of experiments
assesses the validity of our solution in detecting and protecting mobile
applications from man-in-the-middle attacks, without introducing significant
overheads. Finally, MITHYSApp does not require any special permissions nor OS
modifications, as it operates at the application level. These features make
MITHYSApp immediately deployable on a large user base.


title:
Loop Variables and Gauge Invariant Exact Renormalization Group Equations
  for Closed String Theory

abstract:
  We formulate the Exact Renormalization Group on the string world sheet for
closed string backgrounds. The same techniques that were used for open strings
is used here. There are some subtleties. One is that holomorphic factorization
of the closed string vertex operators does not hold in the presence of a cutoff
on the Euclidean world sheet. This introduces extra terms in the Lagrangian at
the cutoff scale and they turn out to be crucial for implementing gauge
invariance. This naive generalization from open string to closed strings
requires a {\em massive} graviton and the gauge symmetry is Abelian, just as in
open string theory. Interestingly, it turns out that if one introduces a non
dynamical background metric (as in background field formalism) and combines a
gauge transformation on the field with a transformation on the coordinates and
background metric, the graviton can be massless. Some examples of background
coordinate covariant equations are worked out explicitly. A preliminary
discussion of massive modes, massive gauge transformations and the role of
world sheet regulator terms is given. Some of the gauge transformations can be
given a geometric meaning if space time is assumed to be complex at some level.


title:
Close binary evolution I. The tidally induced shear mixing in rotating
  binaries

abstract:
  We study how tides in a binary system induce some specific internal shear
mixing, able to substantially modify the evolution of close binaries prior to
mass transfer. We construct numerical models accounting for tidal interactions,
meridional circulation, transport of angular momentum, shears and horizontal
turbulence and consider a variety of orbital periods and initial rotation
velocities. Depending on orbital periods and rotation velocities, tidal effects
may spin down (spin down Case) or spin up (spin up Case) the axial rotation. In
both cases, tides may induce a large internal differential rotation. The
resulting tidally induced shear mixing (TISM) is so efficient that the internal
distributions of angular velocity and chemical elements are greatly influenced.
The evolutionary tracks are modified, and in both cases of spin down and spin
up, large amounts of nitrogen can be transported to the stellar surfaces before
any binary mass transfer. Meridional circulation, when properly treated as an
advection, always tends to counteract the tidal interaction, tending to spin up
the surface when it is braked down and vice versa. As a consequence, the times
needed for the axial angular velocity to become equal to the orbital angular
velocity may be larger than given by typical synchronization timescales. Also,
due to meridional circulation some differential rotation remains in tidally
locked binary systems.


title:
A quantum algorithm for obtaining the energy spectrum of a physical
  system without guessing its eigenstates

abstract:
  We present a quantum algorithm that provides a general approach for obtaining
the energy spectrum of a physical system without making a guess on its
eigenstates. In this algorithm, a probe qubit is coupled to a quantum register
$R$ which consists of one ancilla qubit and a $n$-qubit register that
represents the system. $R$ is prepared in a general reference state, and a
general excitation operator acts on $R$ is constructed. The probe exhibits a
dynamical response only when it is resonant with a transition from the
reference state to an excited state of $R$ which contains the eigenstates of
the system. By varying the probe's frequency, the energy spectrum and the
eigenstates of the system can be obtained.


title:
A Formality quasi-isomorphism for Hochschild cochains over rationals can
  be constructed recursively

abstract:
  It is believed arXiv:0808.2762, arXiv:math/9904055 that, among the
coefficients entering Kontsevich's formality quasi-isomorphism
arXiv:q-alg/9709040, there are irrational (possibly even transcendental)
numbers. In this paper, we prove that a formality quasi-isomorphism for
Hochschild cochains of a polynomial algebra over rationals can be constructed
recursively. The proof that the proposed recursive algorithm works, is based on
the existence of formality quasi-isomorphism over reals. However, the algorithm
requires no explicit knowledge of the coefficients entering Kontsevich's
construction. Although this algorithm completely bypasses Tamarkin's approach
arXiv:math/0003052, arXiv:math/9803025, the construction is inspired by
Proposition 5.8 from the classical paper (Algebra i Analiz, 1990) by V.
Drinfeld.


title:
A novel ER model to relational model transformation algorithm for
  semantically clear high quality database design

abstract:
  Conceptual modelling using the entity relationship (ER) model has been widely
used for database design for a long period of time. However, studies indicate
that creating a satisfactory relational model representation from an ER model
is uncertain due to the insufficiencies both in the transformation methods used
and in the relational model itself. In an effort to solve the issue the
original ER notation has been modified, and accordingly, a new transformation
algorithm has been developed. This paper presents the proposed transformation
algorithm. Using a real world example it shows how the algorithm can be applied
in practice. The paper also discusses how to validate the resulted database and
reclaim the information that it represents.


title:
An Analysis of the DS-CDMA Cellular Uplink for Arbitrary and Constrained
  Topologies

abstract:
  A new analysis is presented for the direct-sequence code-division multiple
access (DS-CDMA) cellular uplink. For a given network topology, closed-form
expressions are found for the outage probability and rate of each uplink in the
presence of path-dependent Nakagami fading and shadowing. The topology may be
arbitrary or modeled by a random spatial distribution with a fixed number of
base stations and mobiles placed over a finite area. The analysis is more
detailed and accurate than existing ones and facilitates the resolution of
network design issues including the influence of the minimum base-station
separation, the role of the spreading factor, and the impact of various
power-control and rate-control policies. It is shown that once power control is
established, the rate can be allocated according to a fixed-rate or
variable-rate policy with the objective of either meeting an outage constraint
or maximizing throughput. An advantage of variable-rate power control is that
it allows an outage constraint to be enforced on every uplink, which is
impossible when a fixed rate is used throughout the network.


title: Aharonov--Bohm effect, electrodynamics postulates, and Lorentz condition

abstract:
  The problem of the relation between the Ahronov-Bohm effect and traditional
postulates of electrodynamics, which claim that only electric and magnetic
fields are observable, is resolved by denial of the statement about validity of
the Maxwell equations for microscopic fields. We proceed from the idea that the
Maxwell equations, as the generalization of experimental data, are valid only
for averaged values. We show that microscopic electrodynamics should be based
on postulation of the d'Alembert equations for four-vector of the
electromagnetic field potential. The Lorentz condition is valid only for the
averages and provides the implementation of the Maxwell equations for averages.
This concept eliminates the problem of electromagnetic field quantization and
provides the correctness of all known results of quantum electrodynamics.
Therefore, the "virtuality" of the longitudinal and scalar photons has a formal
mathematical character, conditioned by the Maxwell equations for averaged
fields. The longitudinal and scalar photons provide not only the Coulomb
interaction of charged particles, but also allow the electrical Aharonov-Bohm
effect.


title: Digital Image Tamper Detection Techniques - A Comprehensive Study

abstract:
  Photographs are considered to be the most powerful and trustworthy media of
expression. For a long time, those were accepted as proves of evidences in
varied fields such as journalism, forensic investigations, military
intelligence, scientific research and publications, crime detection and legal
proceedings, investigation of insurance claims, medical imaging etc. Today,
digital images have completely replaced the conventional photographs from every
sphere of life but unfortunately, they seldom enjoy the credibility of their
conventional counterparts, thanks to the rapid advancements in the field of
digital image processing. The increasing availability of low cost and sometimes
free of cost image editing software such as Photoshop, Corel Paint Shop,
Photoscape, PhotoPlus, GIMP and Pixelmator have made the tampering of digital
images even more easier and a common practice. Now it has become quite
impossible to say whether a photograph is a genuine camera output or a
manipulated version of it just by looking at it. As a result, photographs have
almost lost their reliability and place as proves of evidences in all fields.
This is why digital image tamper detection has emerged as an important research
area to establish the authenticity of digital photographs by separating the
tampered lots from the original ones. This paper gives a brief history of image
tampering and a state-of-the-art review of the tamper detection techniques.


title: Observation of Polarised Microwave Emission from Cosmic Ray Air Showers

abstract:
  We report on the first direct measurement of the basic features of microwave
radio emission from extensive air showers. Using a trigger provided by the
KASCADE-Grande air shower array, the signals of the microwave antennas of the
CROME (Cosmic-Ray Observation via Microwave Emission) experiment have been read
out and searched for signatures of radio emission by high-energy air showers.
Microwave signals have been detected for more than 30 showers with energies
above $3\times10^{16}$\,eV. The observations presented in this Letter are
consistent with a mainly forward-beamed, coherent and polarised emission
process in the GHz frequency range. An isotropic, unpolarised radiation is
disfavoured as the dominant emission model. The measurements show that
microwave radiation offers a new means of studying air showers at very high
energy.


title: A New Operator and Method for Solving Interval Linear Equations

abstract:
  We deal with interval linear systems of equations. We present a new operator,
which generalizes the interval Gauss-Seidel method. Also, based on the new
operator and properties of the well-known methods, we propose a new algorithm,
called the magnitude method. We illustrate by numerical examples that our
approach overcomes some classical methods with respect to both time and
sharpness of enclosures.


title:
The Bishop-Phelps-Bollob\'as property for operators between spaces of
  continuous functions

abstract:
  We show that the space of bounded and linear operators between spaces of
continuous functions on compact Hausdorff topological spaces has the
Bishop-Phelps-Bollob\'as property. A similar result is also proved for the
class of compact operators from the space of continuous functions vanishing at
infinity on a locally compact and Hausdorff topological space into a uniformly
convex space, and for the class of compact operators from a Banach space into a
predual of an $L_1$-space.


title: Exact and Asymptotic Results on Coarse Ricci Curvature of Graphs

abstract:
  Ricci curvature was proposed by Ollivier in a general framework of metric
measure spaces, and it has been studied extensively in the context of graphs in
recent years. In this paper we prove upper bounds for Ollivier's Ricci
curvature for bipartite graphs and for the graphs with girth at least 5. We
also prove a general lower bound on the Ricci curvature in terms of the size of
the maximum matching in an appropriate subgraph. As a consequence, we
characterize the Ricci-flat graphs of girth 5. Moreover, using our general
lower bound and the Birkhoff-von Neumann theorem, we give a necessary and
sufficient condition for the structure of Ricci-flat regular graphs of girth 4.
Finally, we obtain the asymptotic Ricci curvature of random bipartite graphs
$G(n,n, p)$ and random graphs $G(n, p)$, in various regimes of $p$.


title:
Sawtooth patterns in biomolecules force-extension curves: an
  equilibrium-statistical-mechanics theory

abstract:
  We analyze the force-extension curve for a general class of systems, which
are described at the mesoscopic level by a free energy depending on the
extension of its components. Similarly to what is done in real experiments, the
total length of the system is the controlled parameter. This imposes a global
constraint in the minimization procedure leading to the equilibrium values of
the extensions. As a consequence, the force-extension curve has multiple
branches in a certain range of forces. The stability of these branches is
governed by the free energy: there are a series of first-order phase
transitions at certain values of the total length, in which the free energy
itself is continuous but its first derivative, the force, has a finite jump.
This behavior is completely similar to the one observed in real experiments
with biomolecules like proteins, and other complex systems.

categories: physics.bio-ph cond-mat.soft cond-mat.stat-mech q-bio.BM


title: Vector solitons in PT-symmetric lattices

abstract:
  I study vector solitons involving two incoherently-coupled field components
in periodic PT-symmetric optical lattices. The specific symmetry of the lattice
imposes the restrictions on the symmetry of available vector soliton states.
While all configurations with asymmetric intensity distributions are
prohibited, such lattices support multi-hump solitons with equal number of
"in-phase" or "out-of-phase" spots in two components, residing on neighboring
lattice channels. In the focusing medium only the solitons containing
out-of-phase spots in at least one component can be stable, while in the
defocusing medium stability is achieved for structures consisting of in-phase
spots. Mixed-gap vector solitons with components emerging from different gaps
in the lattice spectrum also exist and can be stable in the PT-symmetric
lattice.


title:
How to decompose a permutation into a pair of labeled Dyck paths by
  playing a game

abstract:
  We give a bijection between permutations of length 2n and certain pairs of
Dyck paths with labels on the down steps. The bijection arises from a game in
which two players alternate selecting from a set of 2n items: the permutation
encodes the players' preference ordering of the items, and the Dyck paths
encode the order in which items are selected under optimal play. We enumerate
permutations by certain statistics, AA inversions and BB inversions, which have
natural interpretations in terms of the game. We give new proofs of classical
identities such as \sum_p \prod_{i=1}^n q^{h_i -1} [h_i]_q = [1]_q [3]_q ...
[2n-1]_q where the sum is over all Dyck paths p of length 2n, and the h_i are
the heights of the down steps of p.


title: Nonequilibrium critical Casimir interactions in binary fluids

abstract:
  Colloids immersed in a critical binary liquid mixture are subject to critical
Casimir forces (CCFs) because they confine its concentration fluctuations and
influence the latter via effective surface fields. To date, CCFs have only been
studied in thermodynamic equilibrium. However, due to the critical slowing
down, the order parameter around a particle can easily be perturbed by any
motion of the colloid or by solvent flow. This leads to significant but largely
unexplored changes in the CCF. Here we study the drag force on a single
colloidal particle moving in a near-critical fluid mixture and the relative
motion of two colloids due to the CCF acting on them. In order to account for
the kinetic couplings among the order parameter field, the solvent velocity
field, and the particle motion, we use a fluid particle dynamics method. These
studies extend the understanding of CCFs from thermal equilibrium to
non-equilibrium processes, which are relevant to current experiments, and show
the emergence of significant effects near the critical point.


title:
Joint asymptotic distribution of certain path functionals of the
  reflected process

abstract:
  Let $\tau(x)$ be the first time the reflected process $Y$ of a Levy processes
$X$ crosses x>0. The main aim of the paper is to investigate the asymptotic
dependence of the path functionals: $Y(t) = X(t) - \inf_{0\leq s\leq t}X(s)$,
$M(t,x)=\sup_{0\leq s\leq t}Y(s)-x$ and $Z(x)=Y(\tau(x))-x$. We prove that
under Cramer's condition on X(1), the functionals $Y(t)$, $M(t,y)$ and $Z(x+y)$
are asymptotically independent as $\min\{t,y,x\}\to\infty$. We also
characterise the law of the limiting overshoot $Z(\infty)$ of the reflected
process. If, as $\min\{t,x\}\to\infty$, the quantity $t\te{-\gamma x}$ has a
positive limit ($\gamma$ denotes the Cram\'er coefficient), our results
together with the theorem of Doney & Maller (2005) imply the existence and the
explicit form of the joint weak limit $(Y(\infty),M(\infty),Z(\infty))$.


title: Interferometer design of the KAGRA gravitational wave detector

abstract:
  KAGRA is a cryogenic interferometric gravitational wave detector being
constructed at the underground site of Kamioka mine in Gifu prefecture, Japan.
We performed an optimization of the interferomter design, to achieve the best
sensitivity and a stable operation, with boundary conditions of classical
noises and under various practical constraints, such as the size of the tunnel
or the mirror cooling capacity. Length and alignment sensing schemes for the
robust control of the interferometer are developed. In this paper, we describe
the detailed design of the KAGRA interferometer as well as the reasoning behind
design choices.


title: Quantum Transport in Magnetic Topological Insulator Thin Films

abstract:
  The experimental observation of the long-sought quantum anomalous Hall effect
was recently reported in magnetically doped topological insulator thin films
[Chang et al., Science 340, 167 (2013)]. An intriguing observation is a rapid
decrease from the quantized plateau in the Hall conductance, accompanied by a
peak in the longitudinal conductance as a function of the gate voltage. Here,
we present a quantum transport theory with an effective model for magnetic
topological insulator thin films. The good agreement between theory and
experiment reveals that the measured transport originates from a topologically
nontrivial conduction band which, near its band edge, has concentrated Berry
curvature and a local maximum in group velocity. The indispensable roles of the
broken structure inversion and particle-hole symmetries are also revealed. The
results are instructive for future experiments and transport studies based on
first-principles calculations.


title: Software for Evaluating Relevance of Steps in Algebraic Transformations

abstract:
  Students of our department solve algebraic exercises in mathematical logic in
a computerized environment. They construct transformations step by step and the
program checks the syntax, equivalence of expressions and completion of the
task. With our current project, we add a program component for checking
relevance of the steps.


title: Fractional yields inferred from halo and thick disk stars

abstract:
  Linear [Q/H]-[O/H] relations, Q = Na, Mg, Si, Ca, Ti, Cr, Fe, Ni, are
inferred from a sample (N=67) of recently studied FGK-type dwarf stars in the
solar neighbourhood including different populations. Regression line slope and
intercept estimators and related variance estimators are determined. With
regard to the straight line, [Q/H] = aQ [O/H] + bQ, sample stars display along
a "main sequence", [Q,O] = [aQ,bQ, Delta bQ], leaving aside the two OL stars
which, in most cases (e.g., Na), lie outside. A unit slope, aQ = 1, implies Q
is a primary element synthesised via SNII progenitors in presence of universal
stellar initial mass function (defined as simple primary element). To this
respect, Mg, Si, Ti, show aQ = 1 within 2 sigma(aQ); Cr, Fe, Ni, within 3
sigma(aQ); Na, Ca, exceeding 3 sigma(aQ). The empirical, differential element
abundance distributions are inferred from different subsamples, where related
regression lines represent their theoretical counterparts within the framework
of simple MCBR (multistage closed box + reservoir) chemical evolution models.
Hence the fractional yields are determined and (as an example) a comparison is
shown with their theoretical counterparts inferred from SNII progenitor
nucleosynthesis under the assumption of a power-law stellar initial mass
function. The generalized fractional yields are determined regardless from the
chemical evolution model. The ratio of outflow to star formation rate is
compared for different populations, in the framework of simple MCBR models. The
opposite situation of element abundance variation entirely due to cosmic
scatter is also considered under reasonable assumptions. The related
differential element abundance distribution fits to the data as well as its
counterpart inferred in the opposite limit of instantaneous mixing in presence
of chemical evolution.


title: Gas adsorption on MoS2 monolayer from first-principles calculations

abstract:
  First-principles calculations within density functional theory (DFT) have
been carried out to investigate the adsorption of various gas molecules
including CO, CO2, NH3, NO and NO2 on MoS2 monolayer in order to fully exploit
the gas sensing capabilities of MoS2. By including van der Waals (vdW)
interactions between gas molecules and MoS2, we find that only NO and NO2 can
bind strongly to MoS2 sheet with large adsorption energies, which is in line
with experimental observations. The charge transfer and the variation of
electronic structures are discussed in view of the density of states and
molecular orbitals of the gas molecules. Our results thus provide a theoretical
basis for the potential applications of MoS2 monolayer in gas sensing and give
an explanation for recent experimental findings.


title:
Interferometer responses to gravitational waves: Comparing FINESSE
  simulations and analytical solutions

abstract:
  A comparison of analytic calculations and FINESSE simulations of
interferometer responses to gravitational wave strain. The response to a
gravitational wave is gradually built up from the effect of modulating a space
by a gravitational wave to Sagnac and Michelson interferometers with and
without arm cavities. This document details the steps necessary to perform such
simulations in FINESSE and explicitly derives the interferometer response
equations.


title: Magnetic fields in O stars

abstract:
  Over the last decade, large-scale, organized (generally dipolar) magnetic
fields with a strength between 0.1 and 20 kG were detected in dozens of OB
stars. This contribution reviews the impact of such magnetic fields on the
stellar winds of O-stars, with emphasis on variability and X-ray emission.


title: Differential operators on G/U and the affine Grassmannian

abstract:
  We describe the equivariant cohomology of cofibers of spherical perverse
sheaves on the affine Grassmannian of a reductive algebraic group in terms of
the geometry of the Langlands dual group. In fact we give two equivalent
descriptions: one in terms of D-modules of the basic affine space, and one in
terms of intertwining operators for universal Verma modules. We also construct
natural collections of isomorphisms parametrized by the Weyl group in these
three contexts, and prove that they are compatible with our isomorphisms. As
applications we reprove some results of the first author and of
Braverman-Finkelberg.


title: Arabizi Detection and Conversion to Arabic

abstract:
  Arabizi is Arabic text that is written using Latin characters. Arabizi is
used to present both Modern Standard Arabic (MSA) or Arabic dialects. It is
commonly used in informal settings such as social networking sites and is often
with mixed with English. In this paper we address the problems of: identifying
Arabizi in text and converting it to Arabic characters. We used word and
sequence-level features to identify Arabizi that is mixed with English. We
achieved an identification accuracy of 98.5%. As for conversion, we used
transliteration mining with language modeling to generate equivalent Arabic
text. We achieved 88.7% conversion accuracy, with roughly a third of errors
being spelling and morphological variants of the forms in ground truth.


title:
Performance of the ATLAS Liquid Argon Calorimeter after three years of
  LHC operation and plans for a future upgrade

abstract:
  The ATLAS experiment is designed to study the proton-proton collisions
produced at the Large Hadron Collider (LHC) at CERN. Liquid argon sampling
calorimeters are used for all electromagnetic calorimetry as well as hadronic
calorimetry in the endcaps. After installation in 2004--2006, the calorimeters
were extensively commissioned over the three--year period prior to first
collisions in 2009, using cosmic rays and single LHC beams. Since then,
approximately 27 fb$\mathbf{^{-1}}$ of data have been collected at an
unprecedented center of mass energy. During all these stages, the calorimeter
and its electronics have been operating almost optimally, with a performance
very close to specifications. This paper covers all aspects of these first
years of operation.
  The excellent performance achieved is especially presented in the context of
the discovery of the elusive Higgs boson. The future plans to preserve this
performance until the end of the LHC program are also presented.