title:
True, quasi and unstable Nambu Goldstone modes of the twodimensional
  Bose Einstein condensed magnetoexcitons

abstract:
  The collective elementary excitations of two dimensional magnetoexcitons in a
Bose Einstein condensate with zero wavevector are investigated in the framework
of the Bogoliubov theory of quasi averages. The Hamiltonian of the electrons
and holes lying in the lowest Landau levels contains supplementary interactions
due to virtual quantum transitions of the particles to the excited Landau
levels and back. As a result, the interaction between the magnetoexcitons zero
wavenumbers does not vanish and their BEC becomes stable. The energy spectrum
contains only one gapless,true Nambu Goldstone mode of the second kind,
proportional to the square of wavenumber at small values of wavenumber
describing the optical plasmon type oscillations. There are two exciton type
branches corresponding to normal and abnormal Green functions. Both modes are
gapped with roton type segments at intermediary values of the wavevectors and
can be named quasi NG modes. The fourth branch is the acoustical plasmon type
mode with absolute instability in the region of small and intermediary values
of the wavevectors. All branches have a saturation type dependencies at great
values of the wave vectors. The number and the kind of the true NG modes are in
accordance with the number of the broken symmetry operators.


title: The progenitors of magnetic white dwarfs in open clusters

abstract:
  According to the fossil-field hypothesis magnetic fields are remnants of the
previous stages of evolution. However, population synthesis calculations are
unable to reproduce the magnetic white dwarf (MWD) sample without binary
interaction or inclusion of a population of progenitor with unobservable
small-scale fields. One necessary ingredient in population synthesis is the
initial-to-final-mass relation (IFMR) which describes the mass-loss processes
during the stellar evolution. When white dwarfs are members of open clusters,
their evolutionary histories can be assessed through the use of cluster
properties. In this work, we assess the cluster membership by correlating the
proper-motion of MWDs with the cluster proper-motion and by analyzing the
candidates spectroscopically with our magnetic model spectra in order to
estimate the effective temperature and radii. We identified SDSS
J085523.87+164059.0 to be a proper-motion member of Praesepe. We also included
the data of the formerly identified cluster members NGC 6819-8, WD 0836+201 and
estimated the mass, cooling age and the progenitor masses of the three probable
MWD members of open clusters. According to our analysis, the newly identified
cluster member SDSS J085523.87+164059.0 is an ultra-massive MWD of mass 1.12
$\pm$ 0.11 Msolar. We increase the sample of MWDs with known progenitor masses
to ten, with the rest of the data coming from the common proper motion
binaries. Our investigations show that, when effects of the magnetic fields are
included in the diagnostics, the estimated properties of these cluster MWDs do
not show evidence for deviations from the IFMR. Furthermore, we estimate the
precision of the magnetic diagnostics which would be necessary to determine
quantitatively whether magnetism has any effect on the mass-loss.


title: On Simpson's rule and fractional Brownian motion with H = 1/10

abstract:
  We consider stochastic integration with respect to fractional Brownian motion
(fBm) with $H < 1/2$. The integral is constructed as the limit, where it
exists, of a sequence of Riemann sums. A theorem by Gradinaru, Nourdin, Russo &
Vallois (2005) holds that a sequence of Simpson's rule Riemann sums converges
in probability for a sufficiently smooth integrand $f$ and when the stochastic
process is fBm with $H > 1/10$. For the case $H = 1/10$, we prove that the
sequence of sums converges in distribution. Consequently, we have an It\^o-like
formula for the resulting stochastic integral. The convergence in distribution
follows from a Malliavin calculus theorem that first appeared in Nourdin and
Nualart (2010).


title:
Magnetic Moments of Chromium-Doped Gold Clusters: The Anderson Impurity
  Model in Finite Systems

abstract:
  The magnetic moment of a single impurity atom in a finite free electron gas
is studied in a combined x-ray magnetic circular dichroism spectroscopy and
density functional theory study of size-selected free chromium-doped gold
clusters. The observed size-dependence of the local magnetic moment can
essentially be understood in terms of the Anderson impurity model. Electronic
shell closure in the host metal minimizes the interaction of localized impurity
states with the confined free electron gas and preserves the full magnetic
moment of $\unit[5]{\mu_B}$ in $\mathrm{CrAu}_{2}^{+}$ and
$\mathrm{CrAu}_{6}^{+}$ clusters. Even for open-shell species, large local
moments are observed that scale with the energy gap of the gold cluster. This
indicates that an energy gap in the free electron gas generally stabilizes the
local magnetic moment of the impurity.


title:
Current-induced asymmetries of incompressible stripes in narrow quantum
  Hall systems

abstract:
  We present recent experimental results confirming previously predicted strong
asymmetries of the current distribution in narrow Hall bars under the
conditions of the integer quantum Hall effect (IQHE). Using a previously
developed self-consistent screening and transport theory of the IQHE, we
investigate how these asymmetries, which are due to a non-linear feedback
effect of the imposed current on the electron distribution in the sample,
depend on relevant parameters, such as the strength of the imposed current, the
magnetic field, the temperature, and the collision broadening of the
Landau-quantized energy bands. We find that many aspects of the experimental
results can be understood within this approach, whereas other aspects require
explicit consideration of mechanism, which enforce the breakdown of the IQHE.


title: The Nature of Obscuration in AGN: I. Insights from Host Galaxies

abstract:
  We analyze a sample of 30,000 nearby obscured AGNs with optical spectra from
SDSS and mid-IR photometry from WISE. Our aim is to investigate the AGN host
galaxy properties with mid-IR luminosities as AGN activity indicator, and to
compare with previous studies based on [OIII] emission lines. First we find
that the [3.4] - [4.6] colour has weak dependence on host stellar age, but
strong dependence on AGN activity. We then use a "pair-matching" technique to
subtract the host 4.6 micron contribution. By combining Seyferts with a sample
of SDSS quasars at z < 0.7, we show that the [OIII] and the intrinsic AGN 4.6
micron luminosities correlate roughly linearly over 4 orders of magnitude, but
with substantial scatter. We also compare the partition functions of the total
integrated 4.6 micron and [OIII] line luminosities from Seyferts and a
sub-population of LINERs with significant nuclear 4.6 micron emission, as
function of a variety of host galaxy properties, finding that they are
identical. We conclude, therefore, that [OIII] as an AGN indicator shows no
particular biases as compared to the 4.6 micron luminosity. Our results also
demonstrate that some LINERs do fit in with the expectations of the simple
Unified Model.


title: Parametrics Resonances of a Forced Modified Rayleigh-Duffing Oscillator

abstract:
  We investigate in this paper the superharmonic and subharmonic resonances of
forced modified Rayleigh-Duffing oscillator. We analyse this equation by the
method of multiple scales and we obtain superharmonic, subharmonic resonances
order-two and order-three and primary resonance. We obtain also regions where
steady-state subharmonic responses exist. We also use the amplitude-frequency
curve for demonstrate the effect of various parameters on the response of the
system. Finally, we focus our attention on chaotic motion of this oscillator by
simulation. We obtain that this oscillator is chaotic for certains values for
natural and excitation frequency but chaotic motion is not the same in
subharmonic and superharmonic cases.


title: Continuous Wavelet Transform in Quantum Field Theory

abstract:
  We describe the application of the continuous wavelet transform to
calculation of the Green functions in quantum field theory: scalar $\phi^4$
theory, quantum electrodynamics, quantum chromodynamics. The method of
continuous wavelet transform in quantum field theory presented in M.Altaisky
Phys. Rev. D81(2010)125003 for the scalar $\phi^4$ theory, consists in
substitution of the local fields $\phi(x)$ by those dependent on both the
position $x$ and the resolution $a$. The substitution of the action
$S[\phi(x)]$ by the action $S[\phi_a(x)]$ makes the local theory into nonlocal
one, and implies the causality conditions related to the scale $a$, the region
causality J.D. Christensen and L. Crane, J.Math. Phys 46 (2005) 122502. These
conditions make the Green functions $G(x_1,a_1,...,
x_n,a_n)=<\phi_{a_1}(x_1)...\phi_{a_n}(x_n)> $ finite for any given set of
regions by means of an effective cutoff scale $A=\min (a_1,...,a_n)$.


title:
Estimating second-order characteristics of inhomogeneous spatio-temporal
  point processes: influence of edge correction methods and intensity estimates

abstract:
  We restrict our attention to space-time point pattern data for which we have
a single realisation within a finite region. Second-order characteristics are
used to analyse the spatio-temporal structure of the underlying point process.
In particular, the space-time inhomogeneous pair correlation function and
$K$-function measure the spatio-temporal clustering/regularity and the
spatio-temporal interaction, and thus help with model choice. Non-parametric
estimators of the second-order characteristics require information from outside
the study region, resulting to the so-called edge effects which have to be
corrected, and depend on first-order characteristics, which have to be
estimated in practice. Here, we extend classical edge correction factors to the
spatio-temporal setting and compare the performance of the related estimators
for stationary/non-stationary and/or isotropic/anisotropic point patterns.
Then, we explore the influence of estimated intensity function on these
estimators.


title:
Unusual Kondo physics in a Co impurity atom embedded in noble-metal
  chains

abstract:
  We analyze the conduction bands of the one dimensional noble-metal chains
that contain a Co magnetic impurity by means of ab initio calculations. We
compare the results obtained for Cu and Ag pure chains, as well as O doped Cu,
Ag and Au chains with those previously found for Au pure chains. We find
similar results in the case of Cu and Au hosts, whereas for Ag chains a
different behavior is obtained. Differences and similarities among the
different systems are analyzed by comparing the electronic structure of the
three noble-metal hosts. The d-orbitals of Cu chains at the Fermi level have
the same symmetry as in the case of Au chains. These orbitals hybridize with
the corresponding ones of the Co impurity, giving rise to the possibility of
exhibiting a two-channel Kondo physics.


title:
Nonperturbative corrections and showering in NLO-matched event
  generators

abstract:
  We study contributions from nonperturbative effects and parton showering in
NLO event generators, and present applications to jet final states. We find
pT-dependent and rapidity-dependent corrections which can affect the shape of
observed jet distributions at the LHC. We illustrate numerically the kinematic
shifts in longitudinal momentum distributions from the implementation of
energy-momentum conservation in collinear shower algorithms.


title: On some open questions in bilinear quantum control

abstract:
  The aim of this paper is to provide a short introduction to modern issues in
the control of infinite dimensional closed quantum systems, driven by the
bilinear Schr\"odinger equation. The first part is a quick presentation of some
of the numerous recent developments in the fields. This short summary is
intended to demonstrate the variety of tools and approaches used by various
teams in the last decade. In a second part, we present four examples of
bilinear closed quantum systems. These examples were extensively studied and
may be used as a convenient and efficient test bench for new conjectures.
Finally, we list some open questions, both of theoretical and practical
interest.


title:
A note on the dynamics of linear automorphisms of a measure convolution
  algebra

abstract:
  In this work we are going to study the dynamics of the linear automorphisms
of a measure convolution algebra over a finite group, $T(\mu)=\nu * \mu$. In
order to understand an classify the asymptotic behavior of this dynamical
system we provide an alternative to classical results, a very direct way to
understand convergence of the sequence $\{\nu^{n}\}_{n\in\mathbb{N}}$, where
$G$ is a finite group, $\nu\in\mathcal{P}(G)$ and
$\nu^n=\underbrace{\nu\ast...\ast\nu}_n$, trough the subgroup generated by his
support.


title: Sessile drops in microgravity

abstract:
  Interfaces with a liquid are governing several phenomena. For instance, these
interfaces are giving the shape of sessile droplets and rule the spread of
liquids on surfaces. Here we analyze the shape of sessile axisymmetric drops
and how it is depending on the gravity, obtaining results in agreement with
experimental observations under conditions of microgravity.


title: Reading Ancient Coin Legends: Object Recognition vs. OCR

abstract:
  Standard OCR is a well-researched topic of computer vision and can be
considered solved for machine-printed text. However, when applied to
unconstrained images, the recognition rates drop drastically. Therefore, the
employment of object recognition-based techniques has become state of the art
in scene text recognition applications. This paper presents a scene text
recognition method tailored to ancient coin legends and compares the results
achieved in character and word recognition experiments to a standard OCR
engine. The conducted experiments show that the proposed method outperforms the
standard OCR engine on a set of 180 cropped coin legend words.


title: Stochastic Cellular Automata: Correlations, Decidability and Simulations

abstract:
  This paper introduces a simple formalism for dealing with deterministic, non-
deterministic and stochastic cellular automata in an unified and composable
manner. This formalism allows for local probabilistic correlations, a feature
which is not present in usual definitions. We show that this feature allows for
strictly more behaviors (for instance, number conserving stochastic cellular
automata require these local probabilistic correlations). We also show that
several problems which are deceptively simple in the usual definitions, become
undecidable when we allow for local probabilistic correlations, even in
dimension one. Armed with this formalism, we extend the notion of intrinsic
simulation between deterministic cellular automata, to the non-deterministic
and stochas- tic settings. Although the intrinsic simulation relation is shown
to become undecidable in dimension two and higher, we provide explicit tools to
prove or disprove the existence of such a simulation between any two given
stochastic cellular automata. Those tools rely upon a characterization of
equality of stochastic global maps, shown to be equivalent to the existence of
a stochastic coupling between the random sources. We apply them to prove that
there is no universal stochastic cellular automaton. Yet we provide stochastic
cellular automata achieving optimal partial universality, as well as a
universal non-deterministic cellular automaton.


title: Neighborly and almost neighborly configurations, and their duals

abstract:
  This thesis presents new applications of Gale duality to the study of
polytopes, point configurations and oriented matroids with extremal
combinatorial properties.
  The first part of the thesis explores construction techniques for neighborly
polytopes and oriented matroids. First, we provide a new interpretation of
Shemer's classical Sewing Construction for neighborly polytopes in terms of
lexicographic extensions of oriented matroids. This allows us to provide a
simplified proof and to generalize it to oriented matroids in two ways: the
Extended Sewing Construction and the Gale Sewing Construction. Estimating the
number of polytopes constructed with the later, we can provide new lower bounds
for the number of combinatorial types of neighborly polytopes that even improve
the current best bounds for the number of polytopes. The combination of both
new techniques also allows us to construct many non-realizable neighborly
oriented matroids.
  The degree of a point configuration is the maximal codimension of its
interior faces. The second part of the thesis presents various results on the
combinatorial structure of point configurations whose degree is small compared
to their dimension; specifically, those whose degree is smaller than [(d+1)/2],
the degree of neighborly polytopes. The study of this problem comes motivated
by Ehrhart theory, where a notion equivalent to the degree - for lattice
polytopes - has been widely studied during the last years. In addition, the
study of the degree is also related to the Generalized Lower Bound Theorem for
simplicial polytopes, with Cayley polytopes and with Tverberg theory. Among
other results, we present a complete combinatorial classification for point
configurations of degree 1. Moreover, we show combinatorial restrictions for
configurations of small degree in terms of the novel concepts of weak Cayley
configurations and codegree decompositions.


title: Metameterial refraction characteristics within the millimeter-wave range

abstract:
  Phase delays, spectral, orientation, and angular dependences of radiation
refraction in metamaterial targets have been experimentally studied within the
millimeter-wave range. It has been shown that angular and spectral dependences
have a complicate structure, which demonstrated properties typical both for
positive and negative refraction indexes. At this, a change of refraction
nature occurs in radiation wavelength interval comparable with the sizes of
metamaterial structural elements.


title:
Photonic band-gap in a realistic atomic diamond lattice: penetration
  depth, finite-size and vacancy effects

abstract:
  We study the effects of finite size and of vacancies on the photonic band gap
recently predicted for an atomic diamond lattice. Close to a $J_g=0\to J_e=1$
atomic transition, and for atomic lattices containing up to $N\approx
3\times10^4$ atoms, we show how the density of states can be affected by both
the shape of the system and the possible presence of a fraction of unoccupied
lattice sites. We numerically predict and theoretically explain the presence of
shape-induced border states and of vacancy-induced localized states appearing
in the gap. We also investigate the penetration depth of the electromagnetic
field which we compare to the case of an infinite system.


title: On the algebra of smooth operators

abstract:
  Let s be the space of rapidly decreasing sequences. We give the spectral
representation of normal elements in the Fr\'echet algebra L(s',s) of the
so-called smooth operators. We also characterize closed commutative
*-subalgebras of L(s',s) and establish a H\"older continuous functional
calculus in this algebra. The key tool is the property (DN) of s.


title: The harmonic measure of balls in random trees

abstract:
  We study properties of the harmonic measure of balls in typical large
discrete trees. For a ball of radius $n$ centered at the root, we prove that,
although the size of the boundary is of order $n$, most of the harmonic measure
is supported on a boundary set of size approximately equal to $n^{\beta}$,
where $\beta\approx0.78$ is a universal constant. To derive such results, we
interpret harmonic measure as the exit distribution of the ball by simple
random walk on the tree, and we first deal with the case of critical
Galton-Watson trees conditioned to have height greater than $n$. An important
ingredient of our approach is the analogous continuous model (related to
Aldous' continuum random tree), where the dimension of harmonic measure of a
level set of the tree is equal to $\beta$, whereas the dimension of the level
set itself is equal to $1$. The constant $\beta$ is expressed in terms of the
asymptotic distribution of the conductance of large critical Galton-Watson
trees.


title:
Special Functions of Hypercomplex Variable on the Lattice Based on
  SU(1,1)

abstract:
  Based on the representation of a set of canonical operators on the lattice
$h\mathbb{Z}^n$, which are Clifford-vector-valued, we will introduce new
families of special functions of hypercomplex variable possessing
$\mathfrak{su}(1,1)$ symmetries. The Fourier decomposition of the space of
Clifford-vector-valued polynomials with respect to the ${\rm SO}(n)\times
\mathfrak{su}(1,1)$-module gives rise to the construction of new families of
polynomial sequences as eigenfunctions of a coupled system involving
forward/backward discretizations $E_h^{\pm}$ of the Euler operator
$E=\sum\limits_{j=1}^nx_j \partial_{x_j}$. Moreover, the interpretation of the
one-parameter representation $\mathbb{E}_h(t)=\exp(tE_h^--tE_h^+)$ of the Lie
group ${\rm SU}(1,1)$ as a semigroup $\left(\mathbb{E}_h(t)\right)_{t\geq 0}$
will allows us to describe the polynomial solutions of an homogeneous Cauchy
problem on $[0,\infty)\times h{\mathbb Z}^n$ involving the
differencial-difference operator $\partial_t+E_h^+-E_h^-$.


title:
Non-equilibrium correlations and entanglement in a semiconductor hybrid
  circuit-QED system

abstract:
  We present a theoretical study of a hybrid circuit-QED system composed of two
semiconducting charge-qubits confined in a microwave resonator. The qubits are
defined in terms of the charge states of two spatially separated double quantum
dots (DQDs) which are coupled to the same photon mode in the microwave
resonator. We analyze a transport setup where each DQD is attached to
electronic reservoirs and biased out-of-equilibrium by a large voltage, and
study how electron transport across each DQD is modified by the coupling to the
common resonator. In particular, we show that the inelastic current through
each DQD reflects an indirect qubit-qubit interaction mediated by off-resonant
photons in the microwave resonator. As a result of this interaction, both
charge qubits stay entangled in the steady (dissipative) state. Finite shot
noise cross-correlations between currents across distant DQDs are another
manifestation of this nontrivial steady-state entanglement.


title:
Vitamin D sensitivity to the immune responses and autoimmunity: A
  chemical network model study

abstract:
  Although Vitamin D is believed to be involved in a large number of immune
responses our understanding of these processes at cellular level remained at
infancy. We develop and solve a coarse grained kinetic network model to
quantify the effects of variation of vitamin D on human immunity. The system of
equations accounts for known inter-relation between active and inactive vitamin
D, antigen presenting cells, effector T cells, regulatory T cells and pathogen.
Both time dependent and steady state solutions are obtained. The time dependent
solution of the system of equations reveals that the immune response is rather
strongly regulated in presence of vitamin D. We found quantitatively that lower
than optimum levels of concentration of active vitamin D correspond to weak
regulation where, once a pathogen/antigen enters the body, the nature of the
immune response would be less regulatory and hence more aggressive, or
inflammatory. The steady state solution of our model shows that vitamin D
enhances the tolerance level of immune system, thereby increasing resistance to
autoimmune diseases. Our model and accompanied numerical analyses reveal
another important aspect of immunity: While extremely low levels of vitamin D
could lead to increased risk of autoimmune responses, an overdose (toxic) level
would give rise to too large a tolerant response, leading to the increased risk
of tumors and cancerous cell growth.


title: A Direct Evaluation of the Periods of the Weierstrass Zeta Function

abstract:
  We show how to obtain the difference function of the Weierstrass Zeta
function very directly, by choosing an appropriate order of summation for the
series defining this function. As a byproduct, we show how to obtain the
quasi-modularity of the weight 2 Eisenstein series immediately from the fact
that it appears in this difference function and the homogeneity properties of
the latter.


title: Noise-resistant optimal spin squeezing via quantum control

abstract:
  Entangled atomic states, such as spin squeezed states, represent a promising
resource for a new generation of quantum sensors and atomic clocks. We
demonstrate that optimal control techniques can be used to substantially
enhance the degree of spin squeezing in strongly interacting many-body systems,
even in the presence of noise and imperfections. Specifically, we present a
protocol that is robust to noise which outperforms conventional methods.
Potential experimental implementations are discussed.


title: Bose-Hubbard models with photon pairing in circuit-QED

abstract:
  In this work we study a family of bosonic lattice models that combine an
on-site repulsion term with a nearest-neighbor pairing term, $\sum_{< i,j>}
a^\dagger_i a^\dagger_j + \mathrm{H.c.}$ Like the original Bose-Hubbard model,
the nearest-neighbor term is responsible for the mobility of bosons and it
competes with the local interaction, inducing two-mode squeezing. However,
unlike a trivial hopping, the counter-rotating terms form pairing cannot be
studied with a simple mean-field theory and does not present a quantum phase
transition in phase space. Instead, we show that there is a cross-over from a
pure insulator to long-range correlations that start up as soon as the two-mode
squeezing is switched on. We also show how this model can be naturally
implemented using coupled microwave resonators and superconducting qubits.


title:
Possibility of superconducting gap increase in heterogeneous
  superconductors

abstract:
  A picture of pair scattering on Wigner crystal islands for the earlier
proposed superconducting state in BCS superconductor with characteristic HTSC
properties is presented. The model is supposed to be valid for thin
heterogeneous films and boundaries between superconductors.


title: Evidential Value in ANOVA Results in Favor of Fabrication

abstract:
  Some scientific publications are under suspicion of fabrication of data.
Since humans are bad random number generators, there might be some evidential
value in favor of fabrication in the statistical results as presented in such
papers. In line with Uri Simonsohn (2012, 2013) we study the evidential value
of the results of an ANOVA study in favor of the hypothesis of a dependence
structure in the underlying data.


title: Axler-Zheng type theorem on a class of domains in C^n

abstract:
  We prove a version of Axler-Zheng's Theorem on smooth bounded pseudoconvex
domains in C^n on which the dbar-Neumann operator is compact.


title: Strain-induced ferromagnetism in antiferromagnetic LuMnO3 thin films

abstract:
  Single phase and strained LuMnO3 thin films are discovered to display
co-existing ferromagnetic and antiferromagnetic orders. A large moment
ferromagnetism (approx. 1 muB), which is absent in bulk samples, is shown to
display a magnetic moment distribution that is peaked at the highly-strained
substrate-film interface. We further show that the strain-induced
ferromagnetism and the antiferromagnetic order are coupled via an exchange
field, therefore demonstrating strained rare-earth managanite thin films as
promising candidate systems for new multifunctional devices.


title: 5D relativistic atom optics and interferometry

abstract:
  This contribution is an update of a previous presentation of 5D matter- wave
optics and interferometry with a correction of some algebraic errors.
Electromagnetic interactions are explicitly added in the 5D metric tensor in
complete analogy with Kaluza's work. The 5D Lagrangian is rederived and an
expression for the Hamiltonian suitable for the parabolic approximation is
presented. The corresponding equations of motion are also given. The 5D action
is shown to cancel for the actual trajectory which is a null geodesics of the
5D metric. This presentation is mainly devoted to the classical aspects of the
theory and only general consequences for the quantum phase of matter-waves are
outlined. The application to Bord\'e- Ramsey interferometers is given as an
illustration.


title:
Power sum decompositions of defining equations of reflection
  arrangements

abstract:
  We determine the Waring rank of the fundamental skew invariant of any complex
reflection group whose highest degree is a regular number. This includes all
irreducible real reflection groups.


title:
On an approach for computing the generating functions of the characters
  of simple Lie algebras

abstract:
  We describe a general approach to obtain the generating functions of the
characters of simple Lie algebras which is based on the theory of the quantum
trigonometric Calogero-Sutherland model. We show how the method works in
practice by means of a few examples involving some low rank classical algebras.


title:
Satisfiability of the Two-Variable Fragment of First-Order Logic over
  Trees

abstract:
  We consider the satisfiability problem for the two-variable fragment of
first-order logic over finite unranked trees. We work with signatures
consisting of some unary predicates and the binary navigational predicates
child, right sibling, and their respective transitive closures. We prove that
the satisfiability problem for the logic containing all these predicates is
EXPSPACE-complete. Further, we consider the restriction of the class of
structures to singular trees, i.e., we assume that at every node precisely one
unary predicate holds. We observe that the full logic and even for unordered
trees remain EXPSPACE-complete over finite singular trees, but the complexity
decreases for some weaker logics. Namely, the logic with one binary predicate,
descendant is NEXPTIME-complete, and its guarded version is PSPACE-complete
over finite singular trees, even though both these logics are EXPSPACE-complete
over arbitrary finite trees.


title:
From extortion to generosity, the evolution of zero-determinant
  strategies in the prisoner's dilemma

abstract:
  Recent work has revealed a new class of "zero-determinant" (ZD) strategies
for iterated, two-player games. ZD strategies allow a player to unilaterally
enforce a linear relationship between her score and her opponent's score, and
thus achieve an unusual degree of control over both players' long-term payoffs.
Although originally conceived in the context of classical, two-player game
theory, ZD strategies also have consequences in evolving populations of
players. Here we explore the evolutionary prospects for ZD strategies in the
Iterated Prisoner's Dilemma (IPD). Several recent studies have focused on the
evolution of "extortion strategies" - a subset of zero-determinant strategies -
and found them to be unsuccessful in populations. Nevertheless, we identify a
different subset of ZD strategies, called "generous ZD strategies", that
forgive defecting opponents, but nonetheless dominate in evolving populations.
For all but the smallest population sizes, generous ZD strategies are not only
robust to being replaced by other strategies, but they also can selectively
replace any non-cooperative ZD strategy. Generous strategies can be generalized
beyond the space of ZD strategies, and they remain robust to invasion. When
evolution occurs on the full set of all IPD strategies, selection
disproportionately favors these generous strategies. In some regimes, generous
strategies outperform even the most successful of the well-known Iterated
Prisoner's Dilemma strategies, including win-stay-lose-shift.


title:
Continuation of localised coherent structures in nonlocal neural field
  equations

abstract:
  We study localised activity patterns in neural field equations posed on the
Euclidean plane; such models are commonly used to describe the coarse-grained
activity of large ensembles of cortical neurons in a spatially continuous way.
We employ matrix-free Newton-Krylov solvers and perform numerical continuation
of localised patterns directly on the integral form of the equation. This opens
up the possibility to study systems whose synaptic kernel does not lead to an
equivalent PDE formulation. We present a numerical bifurcation study of
localised states and show that the proposed models support patterns of activity
with varying spatial extent through the mechanism of homoclinic snaking. The
regular organisation of these patterns is due to spatial interactions at a
specific scale associated with the separation of excitation peaks in the chosen
connectivity function. The results presented form a basis for the general study
of localised cortical activity with inputs and, more specifically, for
investigating the localised spread of orientation selective activity that has
been observed in the primary visual cortex with local visual input.


title: Orthogonally Additive Mappings on Hilbert Modules

abstract:
  In this paper, we study the representation of orthogonally additive mappings
acting on Hilbert $C^*$-modules and Hilbert $H^*$-modules. One of our main
results shows that every continuous orthogonally additive mapping $f$ from a
Hilbert module $W$ over $\K(\H)$ or $\H\S(\H)$ to a complex normed space is of
the form $f(x)=T(x)+\Phi(< x, x >)$ for all $x\in W$, where $T$ is a continuous
additive mapping, and $\Phi$ is a continuous linear mapping.


title: Asymptotic formulas for coefficients of inverse theta functions

abstract:
  We determine asymptotic formulas for the coefficients of a natural class of
negative index and negative weight Jacobi forms. These coefficients can be
viewed as a refinement of the numbers $p_k(n)$ of partitions of n into k
colors. Part of the motivation for this work is that they are equal to the
Betti numbers of the Hilbert scheme of points on an algebraic surface S and
appear also as counts of Bogomolny-Prasad-Sommerfield (BPS) states in physics.


title: Bounded Model Checking of an MITL Fragment for Timed Automata

abstract:
  Timed automata (TAs) are a common formalism for modeling timed systems.
Bounded model checking (BMC) is a verification method that searches for runs
violating a property using a SAT or SMT solver. MITL is a real-time extension
of the linear time logic LTL. Originally, MITL was defined for traces of
non-overlapping time intervals rather than the "super-dense" time traces
allowing for intervals overlapping in single points that are employed by the
nowadays common semantics of timed automata. In this paper we extend the
semantics of a fragment of MITL to super-dense time traces and devise a bounded
model checking encoding for the fragment. We prove correctness and completeness
in the sense that using a sufficiently large bound a counter-example to any
given non-holding property can be found. We have implemented the proposed
bounded model checking approach and experimentally studied the efficiency and
scalability of the implementation.


title:
Linear stability analysis of fluid flow between two parallel porous
  stationary plates with small suction and injection

abstract:
  In this work, the linear stability of the viscous incompressible fluid flow
between two parallel horizontal porous stationary plates with the assumption
that there is a small constant suction at upper plate and a small constant
injection at the lower plate is studied.The Navier-Stokes and continuous
equations are reduced to an equation modified by the suction Reynolds number,
which we call modified Orr-Sommerfeld equation. This equation is rewritten as
an eigenvalue problem and is solved numerically using Matlab (Windows Version).
The effect of small suction Reynolds number on the linear stability fluid flow
is discussed.


title: Algorithmic Optimisations for Iterative Deconvolution Methods

abstract:
  We investigate possibilities to speed up iterative algorithms for non-blind
image deconvolution. We focus on algorithms in which convolution with the
point-spread function to be deconvolved is used in each iteration, and aim at
accelerating these convolution operations as they are typically the most
expensive part of the computation. We follow two approaches: First, for some
practically important specific point-spread functions, algorithmically
efficient sliding window or list processing techniques can be used. In some
constellations this allows faster computation than via the Fourier domain.
Second, as iterations progress, computation of convolutions can be restricted
to subsets of pixels. For moderate thinning rates this can be done with almost
no impact on the reconstruction quality. Both approaches are demonstrated in
the context of Richardson-Lucy deconvolution but are not restricted to this
method.


title: Geometry of the Energy Landscape for a Protein Folding on the Ribosome

abstract:
  Energy landscape theory describes how a full-length protein can attain its
native fold by sampling only a tiny fraction of all possible structures.
Although protein folding is now understood to be concomitant with synthesis on
the ribosome, there have been few attempts to modify energy landscape theory by
accounting for cotranslational folding. Here we provide a model for
cotranslational folding that leads to a natural definition of a nested energy
landscape. By applying concepts drawn from submanifold differential geometry,
the physics of protein folding on the ribosome can be explored in a
quantitative manner and conditions on the nested energy landscapes for a good
cotranslational folder are derived.


title: The Section Conjecture for Graphs and Conical Curves

abstract:
  In this paper we formulate and prove a combinatorial version of the section
conjecture for finite groups acting on finite graphs. We apply this result to
the study of rational points and show that finite descent is the only
obstruction to the Hasse principle for mildly singular curves whose components
are all geometrically rational.


title:
Stimulation of Enzyme Reaction Rates by Crystalline Substrate
  Irradiation: Dependence on Identity of Irradiated Substance

abstract:
  The study reported here concerns a phenomenon, discovered and extensively
investigated by Sorin Comorosan, wherein enzyme initial reaction rates are
enhanced as a consequence of incorporation of solutions derived from previously
irradiated crystalline material into the reaction medium. Effective irradiation
times conform to a sharply oscillatory pattern. In most reports, the irradiated
crystalline material has been the substrate for the enzyme reaction to be
studied, but there have been exceptions. The experiments presented here serve
to confirm and extend this latter aspect of the phenomenon. It is found that
the initial reaction rates for the lactic acid dehydrogenase (LDH) conversion
of pyruvate to lactate can be stimulated by irradiation of crystalline deposits
of sodium chloride, sodium bromide, potassium chloride and diatomaceous earth.
Similarly, stimulation of the LDH conversion of lactate to pyruvate is
demonstrated for irradiated sodium chloride. There appears to be no required
chemical feature of the irradiated material other than crystalline state.


title: An algorithm for computing the multigraded Hilbert depth of a module

abstract:
  A method for computing the multigraded Hilbert depth of a module was
presented in [16]. In this paper we improve the method and we introduce an
effective algorithm for performing the computations. In a particular case, the
algorithm may also be easily adapted for computing the Stanley depth of the
module. We further present interesting examples which were found with the help
of an experimental implementation of the algorithm. Thus, we completely solve
several open problems proposed by Herzog in [12].


title: Counting self-avoiding walks

abstract:
  The connective constant $\mu(G)$ of a graph $G$ is the asymptotic growth rate
of the number of self-avoiding walks on $G$ from a given starting vertex. We
survey three aspects of the dependence of the connective constant on the
underlying graph $G$. Firstly, when $G$ is cubic, we study the effect on
$\mu(G)$ of the Fisher transformation (that is, the replacement of vertices by
triangles). Secondly, we discuss upper and lower bounds for $\mu(G)$ when $G$
is regular. Thirdly, we present strict inequalities for the connective
constants $\mu(G)$ of vertex-transitive graphs $G$, as $G$ varies. As a
consequence of the last, the connective constant of a Cayley graph of a
finitely generated group decreases strictly when a new relator is added, and
increases strictly when a non-trivial group element is declared to be a
generator. Special prominence is given to open problems.


title:
Correction of inertial navigation system's errors by the help of
  video-based navigator based on Digital Terrarium Map

abstract:
  This paper deals with the error analysis of a novel navigation algorithm that
uses as input the sequence of images acquired from a moving camera and a
Digital Terrain (or Elevation) Map (DTM/DEM). More specifically, it has been
shown that the optical flow derived from two consecutive camera frames can be
used in combination with a DTM to estimate the position, orientation and
ego-motion parameters of the moving camera. As opposed to previous works, the
proposed approach does not require an intermediate explicit reconstruction of
the 3D world. In the present work the sensitivity of the algorithm outlined
above is studied. The main sources for errors are identified to be the
optical-flow evaluation and computation, the quality of the information about
the terrain, the structure of the observed terrain and the trajectory of the
camera. By assuming appropriate characterization of these error sources, a
closed form expression for the uncertainty of the pose and motion of the camera
is first developed and then the influence of these factors is confirmed using
extensive numerical simulations. The main conclusion of this paper is to
establish that the proposed navigation algorithm generates accurate estimates
for reasonable scenarios and error sources, and thus can be effectively used as
part of a navigation system of autonomous vehicles.


title:
A Nystrom flavored Calder\'on Calculus of order three for two
  dimensional waves

abstract:
  In this paper we present and test a full discretization of all elements of
the Calder\'on Calculus (layer potentials and integral operators) for the
Helmholtz equation in smooth closed curves in the plane. The resulting integral
equations provide approximations of order three for all variables involved.
Test are shown for a wide array of direct, indirect and combined field integral
equation at fixed frequency and for a Convolution Quadrature based
approximation in the time domain.


title:
Statistics of Avalanches with Relaxation, and Barkhausen Noise: A
  Solvable Model

abstract:
  We study a generalization of the Alessandro-Beatrice-Bertotti-Montorsi (ABBM)
model of a particle in a Brownian force landscape, including retardation
effects. We show that under monotonous driving the particle moves forward at
all times, as it does in absence of retardation (Middleton's theorem). This
remarkable property allows us to develop an analytical treatment. The model
with an exponentially decaying memory kernel is realized in Barkhausen
experiments with eddy-current relaxation, and has previously been shown
numerically to account for the experimentally observed asymmetry of
Barkhausen-pulse shapes. We elucidate another qualitatively new feature: the
breakup of each avalanche of the standard ABBM model into a cluster of
sub-avalanches, sharply delimited for slow relaxation under quasi-static
driving. These conditions are typical for earthquake dynamics. With relaxation
and aftershock clustering, the present model includes important ingredients for
an effective description of earthquakes. We analyze quantitatively the limits
of slow and fast relaxation for stationary driving with velocity v>0. The
v-dependent power-law exponent for small velocities, and the critical driving
velocity at which the particle velocity never vanishes, are modified. We also
analyze non-stationary avalanches following a step in the driving magnetic
field. Analytically, we obtain the mean avalanche shape at fixed size, the
duration distribution of the first sub-avalanche, and the time dependence of
the mean velocity. We propose to study these observables in experiments,
allowing to directly measure the shape of the memory kernel, and to trace eddy
current relaxation in Barkhausen noise.


title: Strangeness at high temperatures: from hadrons to quarks

abstract:
  Appropriate combinations of up to fourth order cumulants of net strangeness
fluctuations and their correlations with net baryon number and electric charge
fluctuations, obtained from lattice QCD calculations, have been used to probe
the strangeness carrying degrees of freedom at high temperatures. For
temperatures up to the chiral crossover separate contributions of strange
mesons and baryons can be well described by an uncorrelated gas of hadrons.
Such a description breaks down in the chiral crossover region, suggesting that
the deconfinement of strangeness takes place at the chiral crossover. On the
other hand, the strangeness carrying degrees of freedom inside the quark gluon
plasma can be described by a weakly interacting gas of quarks only for
temperatures larger than twice the chiral crossover temperature. In the
intermediate temperature window these observables show considerably richer
structures, indicative of the strongly interacting nature of the quark gluon
plasma.


title:
Optical investigation of the natural electron doping in thin MoS2 films
  deposited on dielectric substrates

abstract:
  Two-dimensional (2D) compounds provide unique building blocks for novel
layered devices and hybrid photonic structures. However, large
surface-to-volume ratio in thin films enhances the significance of surface
interactions and charging effects requiring new understanding. Here we use
micro-photoluminescence (PL) and ultrasonic force microscopy to explore the
influence of the dielectric environment on optical properties of a few
monolayer MoS2 films. PL spectra for MoS2 films deposited on SiO2 substrates
are found to vary widely. This film-to-film variation is suppressed by
additional capping of MoS2 with SiO2 and SiN, improving mechanical coupling of
MoS2 with surrounding dielectrics. We show that the observed PL
non-uniformities are related to strong variation in the local electron charging
of MoS2 films. In completely encapsulated films, negative charging is enhanced
leading to uniform optical properties. Observed great sensitivity of optical
characteristics of 2D films to surface interactions has important implications
for optoelectronics applications of layered materials.


title: Optimising Problem Formulation for Cylindrical Algebraic Decomposition

abstract:
  Cylindrical algebraic decomposition (CAD) is an important tool for the study
of real algebraic geometry with many applications both within mathematics and
elsewhere. It is known to have doubly exponential complexity in the number of
variables in the worst case, but the actual computation time can vary greatly.
It is possible to offer different formulations for a given problem leading to
great differences in tractability. In this paper we suggest a new measure for
CAD complexity which takes into account the real geometry of the problem. This
leads to new heuristics for choosing: the variable ordering for a CAD problem,
a designated equational constraint, and formulations for truth-table invariant
CADs (TTICADs). We then consider the possibility of using Groebner bases to
precondition TTICAD and when such formulations constitute the creation of a new
problem.


title: Understanding Branch Cuts of Expressions

abstract:
  We assume some standard choices for the branch cuts of a group of functions
and consider the problem of then calculating the branch cuts of expressions
involving those functions. Typical examples include the addition formulae for
inverse trigonometric functions. Understanding these cuts is essential for
working with the single-valued counterparts, the common approach to encoding
multi-valued functions in computer algebra systems. While the defining choices
are usually simple (typically portions of either the real or imaginary axes)
the cuts induced by the expression may be surprisingly complicated. We have
made explicit and implemented techniques for calculating the cuts in the
computer algebra programme Maple. We discuss the issues raised, classifying the
different cuts produced. The techniques have been gathered in the BranchCuts
package, along with tools for visualising the cuts. The package is included in
Maple 17 as part of the FunctionAdvisor tool.


title: PAV ontology: Provenance, Authoring and Versioning

abstract:
  Provenance is a critical ingredient for establishing trust of published
scientific content. This is true whether we are considering a data set, a
computational workflow, a peer-reviewed publication or a simple scientific
claim with supportive evidence. Existing vocabularies such as DC Terms and the
W3C PROV-O are domain-independent and general-purpose and they allow and
encourage for extensions to cover more specific needs. We identify the specific
need for identifying or distinguishing between the various roles assumed by
agents manipulating digital artifacts, such as author, contributor and curator.
  We present the Provenance, Authoring and Versioning ontology (PAV): a
lightweight ontology for capturing just enough descriptions essential for
tracking the provenance, authoring and versioning of web resources. We argue
that such descriptions are essential for digital scientific content. PAV
distinguishes between contributors, authors and curators of content and
creators of representations in addition to the provenance of originating
resources that have been accessed, transformed and consumed. We explore five
projects (and communities) that have adopted PAV illustrating their usage
through concrete examples. Moreover, we present mappings that show how PAV
extends the PROV-O ontology to support broader interoperability.
  The authors strived to keep PAV lightweight and compact by including only
those terms that have demonstrated to be pragmatically useful in existing
applications, and by recommending terms from existing ontologies when
plausible.
  We analyze and compare PAV with related approaches, namely Provenance
Vocabulary, DC Terms and BIBFRAME. We identify similarities and analyze their
differences with PAV, outlining strengths and weaknesses of our proposed model.
We specify SKOS mappings that align PAV with DC Terms.


title: Negativity as a counter of entangled dimensions

abstract:
  Among all entanglement measures negativity arguably is the best known and
most popular tool to quantify bipartite quantum correlations. It is easily
computed for arbitrary states of a composite system and can therefore be
applied to discuss entanglement in an ample variety of situations. However, its
direct physical meaning has not been pointed out yet. We show that the
negativity can be viewed as an estimator of how many degrees of freedom of two
subsystems are entangled. As it is possible to give lower bounds for the
negativity even in a device-independent setting, it is the appropriate quantity
to certify quantumness of both parties in a bipartite system and to determine
the minimum number of dimensions that contribute to the quantum correlations.


title:
Lay-up Optimization of Laminated Composites: Mixed Approach with Exact
  Feasibility Bounds on Lamination Parameters

abstract:
  We suggest modified bi-level approach for finding the best stacking sequence
of laminated composite structures subject to mechanical, blending and
manufacturing constraints. We propose to use both the number of plies laid up
at predefined angles and lamination parameters as independent variables at
outer (global) stage of bi-level scheme aimed to satisfy buckling, strain and
percentage constraints. Our formulation allows precise definition of the
feasible region of lamination parameters and greatly facilitates the solution
of inner level problem of finding the optimal stacking sequence.


title:
Generalization of different type integral inequalities for
  ({\alpha},m)-convex functions via fractional integrals

abstract:
  In this paper, a general integral identity for a twice differentiable
functions is derived. By using of this identity, the author establishes some
new Hermite-Hadamard type and Simpson type inequalities for differentiable
({\alpha},m)-convex functions via Riemann Liouville fractional integral.


title:
CdS nanoparticles capped with 1-substituted 5-thiotetrazoles: Synthesis,
  characterization, and thermolysis of the surfactant

abstract:
  We propose a new type of surfactants, namely, tetrazole derivatives which can
be controllably removed from the nanoparticle surface. Tetrazoles are a
peculiar class of heterocyclic compounds. The presence of four nitrogen atoms
in the tetrazole ring determines their interesting physical and chemical
properties. Tetrazoles show high thermal stability below 200C while decomposing
at higher temperature with formation of gaseous products and no or very little
solid residue. Moreover, the tetrazole group is known as an important ligand in
coordination chemistry. Its donor nitrogen atoms can bind to various metal ions
leading to stable complexes with diverse coordination modes of the heteroring.
We report the synthesis of CdS NPs capped with 1-R-5-thiotetrazoles using two
different synthetic schemes: solution-phase and solventless single precursor
approaches. In both synthetic procedures cadmium thiotetrazolates were used as
cadmium precursors and sources of surfactant.


title: Properties of Causal Holographic Information

abstract:
  Causal holographic information [1] is a variant of the Ryu-Takayanagi
proposal for the entanglement entropy of a spatial region in the context of
AdS/CFT, but with the bulk surface defined by causality rather than
extremality. We investigate the properties of causal holographic information,
focusing in particular on the universal coefficient of the logarithmically
divergent term. We find that this coefficient contains a novel conformal
invariant that cannot be written as an integral of local quantities. By
considering higher curvature corrections in the bulk, we identify the
coefficient of the a and c central charges in 4 dimensions. Finally, we
speculate about which CFT quantity could correspond to the causal holographic
information.


title: Learning Densities Conditional on Many Interacting Features

abstract:
  Learning a distribution conditional on a set of discrete-valued features is a
commonly encountered task. This becomes more challenging with a
high-dimensional feature set when there is the possibility of interaction
between the features. In addition, many frequently applied techniques consider
only prediction of the mean, but the complete conditional density is needed to
answer more complex questions. We demonstrate a novel nonparametric Bayes
method based upon a tensor factorization of feature-dependent weights for
Gaussian kernels. The method makes use of multistage feature selection for
dimension reduction. The resulting conditional density morphs flexibly with the
selected features.


title: Stability analysis of polarization attraction in optical fibers

abstract:
  The nonlinear cross-polarization interaction among two intense
counterpropagating beams in a span of lossless randomly birefringent telecom
optical fiber may lead to the attraction an initially polarization scrambled
signal towards wave with a well-defined state of polarization at the fiber
output. By exploiting exact analytical solutions of the nonlinear polarization
coupling process we carry out a linear stability study which reveals that
temporally stable stationary solutions are only obtained whenever the output
signal polarization is nearly orthogonal to the input pump polarization.
Moreover, we predict that polarization attraction is acting in full strength
whenever equally intense signal and pump waves are used.


title: The A-polynomial And Holonomy Perturbations

abstract:
  Dunfield-Garoufalidis and Boyer-Zhang proved that the A-polynomial of a
nontrivial knot in $S^{3}$ is nontrivial. In this paper, we use holonomy
perturbations to prove the non-triviality of the A-polynomial for a nontrivial,
null-homotopic knot in an irreducible 3-manifold. Also, we give a strong
constraint on the A-polynomial of a knot in the 3-sphere.


title: Heat invariants of the Steklov problem

abstract:
  We study the heat trace asymptotics associated with the Steklov eigenvalue
problem on a Riemannian manifold with boundary. In particular, we describe the
structure of the Steklov heat invariants and compute the first few of them
explicitly in terms of the scalar and mean curvatures. This is done by applying
the Seeley calculus to the Dirichlet-to-Neumann operator, whose spectrum
coincides with the Steklov eigenvalues. As an application, it is proved that a
three--dimensional ball is uniquely defined by its Steklov spectrum among all
Euclidean domains with smooth connected boundary.


title: From symmetry-protected topological order to Landau order

abstract:
  Focusing on the particular case of the discrete symmetry group Z_N x Z_N, we
establish a mapping between symmetry protected topological phases and symmetry
broken phases for one-dimensional spin systems. It is realized in terms of a
non-local unitary transformation which preserves the locality of the
Hamiltonian. We derive the image of the mapping for various phases involved,
including those with a mixture of symmetry breaking and topological protection.
Our analysis also applies to topological phases in spin systems with arbitrary
continuous symmetries of unitary, orthogonal and symplectic type. This is
achieved by identifying suitable subgroups Z_N x Z_N in all these groups,
together with a bijection between the individual classes of projective
representations.

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


title: Finding Short Paths on Polytopes by the Shadow Vertex Algorithm

abstract:
  We show that the shadow vertex algorithm can be used to compute a short path
between a given pair of vertices of a polytope P = {x : Ax \leq b} along the
edges of P, where A \in R^{m \times n} is a real-valued matrix. Both, the
length of the path and the running time of the algorithm, are polynomial in m,
n, and a parameter 1/delta that is a measure for the flatness of the vertices
of P. For integer matrices A \in Z^{m \times n} we show a connection between
delta and the largest absolute value Delta of any sub-determinant of A,
yielding a bound of O(Delta^4 m n^4) for the length of the computed path. This
bound is expressed in the same parameter Delta as the recent non-constructive
bound of O(Delta^2 n^4 \log (n Delta)) by Bonifas et al.
  For the special case of totally unimodular matrices, the length of the
computed path simplifies to O(m n^4), which significantly improves the
previously best known constructive bound of O(m^{16} n^3 \log^3(mn)) by Dyer
and Frieze.


title: In the sight of my wearable camera: Classifying my visual experience

abstract:
  We introduce and we analyze a new dataset which resembles the input to
biological vision systems much more than most previously published ones. Our
analysis leaded to several important conclusions. First, it is possible to
disambiguate over dozens of visual scenes (locations) encountered over the
course of several weeks of a human life with accuracy of over 80%, and this
opens up possibility for numerous novel vision applications, from early
detection of dementia to everyday use of wearable camera streams for automatic
reminders, and visual stream exchange. Second, our experimental results
indicate that, generative models such as Latent Dirichlet Allocation or
Counting Grids, are more suitable to such types of data, as they are more
robust to overtraining and comfortable with images at low resolution, blurred
and characterized by relatively random clutter and a mix of objects.


title: A study of local and non-local spatial densities in quantum field theory

abstract:
  We use a one-dimensional model system to compare the predictions of two
different 'yardsticks' to compute the position of a particle from its quantum
field theoretical state. Based on the first yardstick (defined by the
Newton-Wigner position operator), the spatial density can be arbitrarily narrow
and its time-evolution is superluminal for short time intervals. Furthermore,
two spatially distant particles might be able to interact with each other
outside the light cone, which is manifested by an asymmetric spreading of the
spatial density. The second yardstick (defined by the quantum field operator)
does not permit localized states and the time evolution is subluminal.


title: Solution of the Decision Making Problems using Fuzzy Soft Relations

abstract:
  The Fuzzy Modeling has been applied in a wide variety of fields such as
Engineering and Management Sciences and Social Sciences to solve a number
Decision Making Problems which involve impreciseness, uncertainty and vagueness
in data. In particular, applications of this Modeling technique in Decision
Making Problems have remarkable significance. These problems have been tackled
using various theories such as Probability theory, Fuzzy Set Theory, Rough Set
Theory, Vague Set Theory, Approximate Reasoning Theory etc. which lack in
parameterization of the tools due to which they could not be applied
successfully to such problems. The concept of Soft Set has a promising
potential for giving an optimal solution for these problems. With the
motivation of this new concept, in this paper we define the concepts of Soft
Relation and Fuzzy Soft Relation and then apply them to solve a number of
Decision Making Problems. The advantages of Fuzzy Soft Relation compared to
other paradigms are discussed. To the best of our knowledge this is the first
work on the application of Fuzzy Soft Relation to the Decision Making Problems.


title: Solution of System of Linear Equations - A Neuro-Fuzzy Approach

abstract:
  Neuro-Fuzzy Modeling has been applied in a wide variety of fields such as
Decision Making, Engineering and Management Sciences etc. In particular,
applications of this Modeling technique in Decision Making by involving complex
Systems of Linear Algebraic Equations have remarkable significance. In this
Paper, we present Polak-Ribiere Conjugate Gradient based Neural Network with
Fuzzy rules to solve System of Simultaneous Linear Algebraic Equations. This is
achieved using Fuzzy Backpropagation Learning Rule. The implementation results
show that the proposed Neuro-Fuzzy Network yields effective solutions for
exactly determined, underdetermined and over-determined Systems of Linear
Equations. This fact is demonstrated by the Computational Complexity analysis
of the Neuro-Fuzzy Algorithm. The proposed Algorithm is simulated effectively
using MATLAB software. To the best of our knowledge this is the first work of
the Systems of Linear Algebraic Equations using Neuro-Fuzzy Modeling.


title: An introduction to the Vainshtein mechanism

abstract:
  We introduce the Vainshtein mechanism which plays a crucial role in massive
gravities, as well as in related theories such as Galileons and their
extensions. This mechanism, also known as k-mouflage, allows to hide via non
linear effects - typically for source distances smaller than a so-called
Vainshtein radius which depends on the source and on the theory considered -
some degrees of freedom whose effects are then only left important at large
distances, e.g. for cosmology. It is introduced here in non linear Fierz-Pauli
theories (massive gravities), including the dRGT theories, in their decoupling
limits, as well as in other models such as DGP model or generalized Galileons.
This presentation is self-contained and before discussing the Vainshtein
mechanism we introduce some useful results and concepts concerning massive
gravity, such as the vDVZ discontinuity, the decoupling limits or the
Boulware-Deser ghost.


title:
pH-dependent Response of Coiled Coils: A Coarse-Grained Molecular
  Simulation Study

abstract:
  In a recent work we proposed a coarse-grained methodology for studying the
response of peptides when simulated at different values of pH; in this work we
extend the methodology to analyze the pH-dependent behavior of coiled coils.
This protein structure presents a remarkable chain stiffness andis formed by
two or more long helical peptides that are interacting like the strands of a
rope. Chain length and rigidity are the key aspects needed to extend previous
peptide interaction potentials to this particular case; however the original
model is naturally recovered when the length or the ridigity of the simulated
chain are reduced. We apply the model and discuss results for two cases: (a)
the folding/unfolding transition of a generic coiled coil as a function of pH;
(b) behavior of a specific sequence as a function of the acidity conditions. In
this latter case results are compared with experimental data from the
literature in order to comment about the consistency of our approach.


title: Imaging Universal Conductance Fluctuations in Graphene

abstract:
  We study conductance fluctuations (CF) and the sensitivity of the conductance
to the motion of a single scatterer in two-dimensional massless Dirac systems.
Our extensive numerical study finds limits to the predicted universal value of
CF. We find that CF are suppressed for ballistic systems near the Dirac point
and approach the universal value at sufficiently strong disorder. The
conductance of massless Dirac fermions is sensitive to the motion of a single
scatterer. CF of order $e^2/h$ result from the motion of a single impurity by a
distance comparable to the Fermi wavelength. This result applies to graphene
systems with a broad range of impurity strength and concentration while the
dependence on the Fermi wavelength can be explored {\em via} gate voltages. Our
prediction can be tested by comparing graphene samples with varying amounts of
disorder and can be used to understand interference effects in mesoscopic
graphene devices.


title:
Highly collimated source of cold Rubidium atoms from a two dimensional
  magneto-optical trap

abstract:
  Using a blue detuned laser shaped in a Laguerre-Gaussian donut mode we highly
collimate the output of a two dimensional magneto-optical trap. The resulting
atomic beam has a 1 mm diameter, its divergence is reduced from 40 down to 3
mrad and the atomic density is increased by a factor of 200. The collimation
effect has been studied versus the order of the Laguerre-Gaussian mode (up to
10) and the laser atom frequency detuning (2 to 120 GHz). The 2D-colli-MOT
study allows us to determine the best conditions which minimize the atom
heating due to residual light absorption and optimize the collimation effect.
The 2D-colli MOT could provide a new tool to fill a 3D-MOT using lasers with
millimeter range diameters and thus sparing the laser power.


title: Relation-algebraic and Tool-supported Control of Condorcet Voting

abstract:
  We present a relation-algebraic model of Condorcet voting and, based on it,
relation-algebraic solutions of the constructive control problem via the
removal of voters.
  We consider two winning conditions, viz. to be a Condorcet winner and to be
in the (Gilles resp. upward) uncovered set. For the first condition the control
problem is known to be NP-hard; for the second condition the NP-hardness of the
control problem is shown in the paper. All relation-algebraic specifications we
will develop in the paper immediately can be translated into the programming
language of the BDD-based computer system RelView. Our approach is very
flexible and especially appropriate for prototyping and experimentation, and as
such very instructive for educational purposes. It can easily be applied to
other voting rules and control problems.


title:
Numerical modelling of gamma-ray emission produced by electrons
  originating from the magnetospheres of millisecond pulsars in globular
  clusters

abstract:
  Globular clusters are source of gamma-ray radiation. At GeV energies, their
emission is attributed to magnetospheric activity of millisecond pulsars
residing in the clusters. Inverse Compton scattering of ambient photon fields
on relativistic particles diffusing through cluster environment is thought to
be the source of GeV-TeV emission of globular clusters. Using pair starved
polar cap model gamma-ray emission from synthetic millisecond pulsar was
modelled. In addition to pulsar emission characteristics, the synthetic pulsar
model yielded spectra of electrons escaping pulsar magnetosphere. To simulate
gamma-ray emission of globular cluster, both products of synthetic millisecond
pulsar modelling were used. Gamma-ray spectra of synthetic millisecond pulsars
residing in the cluster were summed to produce the magnetospheric component of
cluster emission. Electrons ejected by these pulsars were injected into
synthetic globular cluster environment. Their diffusion and interaction, both,
with cluster magnetic field and ambient photon fields, were performed with
Bednarek & Sitarek (2007) model yielding ICS component of cluster emission. The
sum of the magnetospheric and ICS components gives the synthetic gamma-ray
spectrum of globular cluster. The synthetic cluster spectrum stretches from GeV
to TeV energies. Detailed modelling was preformed for two globular clusters:
Ter 5 and 47 Tuc. Simulations are able to reproduce (within errors) the shape
and the flux level of the GeV part of the spectrum observed for both clusters
with the Fermi/LAT instrument. The synthetic flux level obtained in the TeV
part of the clusters' spectrum is in agreement with a H.E.S.S. upper limit
determined for 47 Tuc, and with emission level recently detected for Ter 5 with
H.E.S.S. telescope. The synthetic globular cluster model, however, is not able
to reproduce the exact shape of the TeV spectrum observed for Ter 5.


title:
Seventy six T dwarfs from the UKIDSS LAS: benchmarks, kinematics and an
  updated space density

abstract:
  We report the discovery of 76 new T dwarfs from the UKIDSS Large Area Survey
(LAS). Near-infrared broad and narrow-band photometry and spectroscopy are
presented for the new objects, along with WISE and warm-Spitzer photometry.
Proper motions for 128 UKIDSS T dwarfs are presented from a new two epoch LAS
proper motion catalogue. We use these motions to identify two new benchmark
systems: LHS 6176AB, a T8+M4 pair and HD118865AB, a T5.5+F8 pair. Using age
constraints from the primaries and evolutionary models to constrain the radii
we have estimated their physical properties from their bolometric luminosity.
We compare the colours and properties of known benchmark T dwarfs to the latest
model atmospheres and draw two principal conclusions. Firstly, it appears that
the H - [4.5] and J - W2 colours are more sensitive to metallicity than has
previously been recognised, such that differences in metallicity may dominate
over differences in Teff when considering relative properties of cool objects
using these colours. Secondly, the previously noted apparent dominance of young
objects in the late-T dwarf sample is no longer apparent when using the new
model grids and the expanded sample of late-T dwarfs and benchmarks. This is
supported by the apparently similar distribution of late-T dwarfs and
earlier-type T dwarfs on reduced proper motion diagrams that we present.
Finally, we present updated space densities for the late-T dwarfs, and compare
our values to simulation predictions and those from WISE.


title: Probing the quantum nature of spacetime by diffusion

abstract:
  Many approaches to quantum gravity have resorted to diffusion processes to
characterize the spectral properties of the resulting quantum spacetimes. We
critically discuss these quantum-improved diffusion equations and point out
that a crucial property, namely positivity of their solutions, is not preserved
automatically. We then construct a novel set of diffusion equations with
positive semi-definite probability densities, applicable to Asymptotically Safe
gravity, Horava-Lifshitz gravity and Loop Quantum Gravity. These recover all
previous results on the spectral dimension and shed further light on the
structure of the quantum spacetimes by assessing the underlying stochastic
processes. Pointing out that manifestly different diffusion processes lead to
the same spectral dimension, we propose the probability distribution of the
diffusion process as a refined probe of quantum spacetime.


title: A search for rocky planets transiting brown dwarfs

abstract:
  Exoplanetary science has reached a historic moment. The James Webb Space
Telescope will be capable of probing the atmospheres of rocky planets, and
perhaps even search for biologically produced gases. However this is contingent
on identifying suitable targets before the end of the mission. A race
therefore, is on, to find transiting planets with the most favorable
properties, in time for the launch. Here, we describe a realistic opportunity
to discover extremely favorable targets - rocky planets transiting nearby brown
dwarfs - using the Spitzer Space Telescope as a survey instrument. Harnessing
the continuous time coverage and the exquisite precision of Spitzer in a 5,400
hour campaign monitoring nearby brown dwarfs, we will detect a handful of
planetary systems with planets as small as Mars. The survey we envision is a
logical extension of the immense progress that has been realized in the field
of exoplanets and a natural outcome of the exploration of the solar
neighborhood to map where the nearest habitable rocky planets are located (as
advocated by the 2010 Decadal Survey). Our program represents an essential step
towards the atmospheric characterization of terrestrial planets and carries the
compelling promise of studying the concept of habitability beyond Earth-like
conditions. In addition, our photometric monitoring will provide invaluable
observations of a large sample of nearby brown dwarfs situated close to the M/L
transition. This is why, we also advocate an immediate public release of the
survey data, to guarantee rapid progress on the planet search and provide a
treasure trove of data for brown dwarf science.


title:
Perturbative Non-Equilibrium Thermal Field Theory to all Orders in
  Gradient Expansion

abstract:
  We present a new perturbative formulation of non-equilibrium thermal field
theory, based upon non-homogeneous free propagators and time-dependent
vertices. The resulting time-dependent diagrammatic perturbation series are
free of pinch singularities without the need for quasi-particle approximation
or effective resummation of finite widths. After arriving at a physically
meaningful definition of particle number densities, we derive master time
evolution equations for statistical distribution functions, which are valid to
all orders in perturbation theory and to all orders in a gradient expansion.
For a scalar model, we perform a perturbative loopwise truncation of these
evolution equations, whilst still capturing fast transient behaviour, which is
found to be dominated by energy-violating processes, leading to the
non-Markovian evolution of memory effects.


title:
Universality Aspects of Layering Transitions in Ferromagnetic
  Blume-Capel Thin Films

abstract:
  Critical phenomena and universality behavior of ferromagnetic thin films
described by a spin-1 Blume-Capel Hamiltonian has been examined for various
thickness values ranging from 3 to 40 layers. Using effective field theory, we
have found that crystal field interactions significantly affects the critical
value of surface to bulk ratio of exchange interactions $R_{c}$ at which the
critical temperature becomes independent of film thickness $L$. Moreover, we
have extracted the shift exponent $\lambda$ from computed data. Based on the
results, we have shown that in the presence of surface exchange enhancement,
the system may exhibit a dimensional crossover. We have also found that
presence of crystal field interactions does not affect the value of $\lambda$.
Hence, a ferromagnetic spin-1/2 thin film is in the same universality class
with its spin-1 counterpart.


title:
The Interstellar Bubbles of G38.9-0.4 and the Impact of Stellar Feedback
  on Star Formation

abstract:
  We present a study of the star formation (SF) region G38.9-0.4 using publicly
available multiwavelength Galactic Plane surveys from ground- and space-based
observatories. This region is composed of four bright mid-IR bubbles and
numerous infrared dark clouds. Two bubbles, N 74 and N 75, each host a star
cluster anchored by a single O9.5V star. We identified 162 young stellar
objects (YSOs) and classify 54 as stage I, 7 stage II, 6 stage III, and 32
ambiguous. We do not detect the classical signposts of triggered SF, i.e.,
star-forming pillars or YSOs embedded within bubble rims. We conclude that
feedback-triggered SF has not occurred in G38.9-0.4. The YSOs are
preferentially coincident with infrared dark clouds. This leads to a strong
correlation between areal YSO mass surface density and gas mass surface density
with a power law slope near 1.3, which closely matches the Schmidt-Kennicutt
Law. The correlation is similar inside and outside the bubbles and may mean
that the SF efficiency is neither enhanced nor supressed in regions potentially
influenced by stellar feedback. This suggests that gas density, regardless of
how it is collected, is a more important driver of SF than stellar feedback.
Larger studies should be able to quantify the fraction of all SF that is
feedback-triggered by determining the fraction SF, feedback-compressed gas
surrounding HII regions relative to that already present in molecular clouds.


title: On DIS Wilson coefficients in N = 4 super Yang-Mills theory

abstract:
  In this note we evaluate Wilson coefficients for "deep inelastic scattering"
(DIS) in N=4 SYM theory at NLO in perturbation theory, using as a probe an
R-symmetry conserved current. They exhibit uniform transcendentality and
coincide with the piece of highest transcendentality in the corresponding QCD
Wilson coefficients. We extract from the QCD result a NNLO prediction for the
N=4 SYM Wilson coefficient, and comment on the features of its Regge limit
asymptotics.


title:
Scalable, Non-Invasive Glucose Sensor Based on Boronic Acid
  Functionalized Carbon Nanotube Transistors

abstract:
  We developed a scalable, label-free all-electronic sensor for D-glucose based
on a carbon nanotube transistor functionalized with pyrene-1-boronic acid. This
sensor responds to glucose in the range 1 uM - 100 mM, which includes typical
glucose concentrations in human blood and saliva. Control experiments establish
that functionalization with the boronic acid provides high sensitivity and
selectivity for glucose. The devices show better sensitivity than commercial
blood glucose meters and could represent a general strategy to bloodless
glucose monitoring by detecting low concentrations of glucose in saliva.

categories: cond-mat.mtrl-sci cond-mat.mes-hall physics.bio-ph physics.chem-ph physics.med-ph


title:
A flat band at the chemical potential of a Fe1.03Te0.94S0.06
  superconductor observed by angle-resolved photoemission spectroscopy

abstract:
  The electronic structure of superconducting Fe1.03Te0.94S0.06 has been
studied by angle resolved photoemission spectroscopy (ARPES). Experimental band
topography is compared to the calculations using the methods of
Korringa-Kohn-Rostoker (KKR) with coherent potential approximation (CPA) and
linearized augmented plane wave with local orbitals (LAPW+LO). The region of
the Gamma point exhibits two hole pockets and a quasiparticle peak close to the
chemical potential with undetectable dispersion. This flat band with mainly dz2
orbital character is formed most likely by the top of the outer hole pocket or
is an evidence of the third hole band. It may cover up to 3 % of the Brillouin
zone volume and should give rise to a Van Hove singularity. Studies performed
for various photon energies indicate that at least one of the hole pockets has
a two-dimensional character. The apparently nondispersing peak at the chemical
potential is clearly visible for 40 eV and higher photon energies, due to an
effect of photoionisation cross section rather than band dimensionality.
Orbital characters calculated by LAPW+LO for stoichiometric FeTe do not reveal
the flat dz2 band but are in agreement with the experiment for the other
dispersions around Gamma in Fe1.03Te0.94S0.06.


title: Ferroelectricity from iron valence ordering in rare earth ferrites?

abstract:
  The possibility of multiferroicity arising from charge ordering in LuFe2O4
and structurally related rare earth ferrites is reviewed. Recent experimental
work on macroscopic indications of ferroelectricity and microscopic
determination of coupled spin and charge order indicates that this scenario
does not hold. Understanding the origin of the experimentally observed charge
and spin order will require further theoretical work. Other aspects of recent
research in these materials, such as geometrical frustration effects, possible
electric-field-induced transitions, or orbital order are also briefly treated.


title: Robust Belief Roadmap: Planning Under Intermittent Sensing

abstract:
  In this paper, we extend the recent body of work on planning under
uncertainty to include the fact that sensors may not provide any measurement
owing to misdetection. This is caused either by adverse environmental
conditions that prevent the sensors from making measurements or by the
fundamental limitations of the sensors. Examples include RF-based ranging
devices that intermittently do not receive the signal from beacons because of
obstacles; the misdetection of features by a camera system in detrimental
lighting conditions; a LIDAR sensor that is pointed at a glass-based material
such as a window, etc.
  The main contribution of this paper is twofold. We first show that it is
possible to obtain an analytical bound on the performance of a state estimator
under sensor misdetection occurring stochastically over time in the
environment. We then show how this bound can be used in a sample-based path
planning algorithm to produce a path that trades off accuracy and robustness.
Computational results demonstrate the benefit of the approach and comparisons
are made with the state of the art in path planning under state uncertainty.


title:
Direct Spectro-Temporal Characterization of Femtosecond
  Extreme-Ultraviolet Pulses

abstract:
  We propose a method for a straightforward characterization of the temporal
shape of femtosecond pulses in the extreme-ultraviolet/soft X-ray spectral
region. The approach is based on the presence of a significant linear frequency
chirp in the pulse. This allows to establish an homothetic relation between the
pulse spectrum and its temporal profile. The theoretical approach is
reminiscent of the one employed by Fraunhofer for describing far-field
diffraction. As an application, we consider the case of a seeded free-electron
laser (FEL). Theory is successfully benchmarked with numerical simulations and
with experimental data collected on the FERMI@Elettra FEL. The proposed method
provides FEL users with an on-line, shot-to-shot spectro-temporal diagnostic
for time-resolved experiments.


title:
Direct microscopic calculations of nuclear level densities in the shell
  model Monte Carlo approach

abstract:
  Nuclear level densities are crucial for estimating statistical nuclear
reaction rates. The shell model Monte Carlo method is a powerful approach for
microscopic calculation of state densities in very large model spaces. However,
these state densities include the spin degeneracy of each energy level, whereas
experiments often measure level densities in which each level is counted just
once. To enable the direct comparison of theory with experiments, we introduce
a method to calculate directly the level density in the shell model Monte Carlo
approach. The method employs a projection on the minimal absolute value of the
magnetic quantum number. We apply the method to nuclei in the iron region as
well as the strongly deformed rare-earth nucleus $^{162}$Dy. We find very good
agreement with experimental data including level counting at low energies,
charged particle spectra and Oslo method at intermediate energies, neutron and
proton resonance data, and Ericson's fluctuation analysis at higher excitation
energies.

categories: nucl-th cond-mat.mes-hall cond-mat.str-el nucl-ex


title: Classification of multipartite entanglement in all dimensions

abstract:
  We provide a systematic classification of multiparticle entanglement in terms
of equivalence classes of states under stochastic local operations and
classical communication (SLOCC). We show that such an SLOCC equivalency class
of states is characterized by ratios of homogenous polynomials that are
invariant under local action of the special linear group. We then construct the
complete set of all such SL-invariant polynomials (SLIPs). Our construction is
based on Schur-Weyl duality and applies to any number of qudits in all (finite)
dimensions. In addition, we provide an elegant formula for the dimension of the
homogenous SLIPs space of a fixed degree as a function of the number of qudits.
The expressions for the SLIPs involve in general many terms, but for the case
of qubits we also provide much simpler expressions.


title:
Upper bound of typical ranks of m x n x ((m-1)n-1) tensors over the real
  number field

abstract:
  Let $3\leq m\leq n$. We study typical ranks of $m\times n\times ((m-1)n-1)$
tensors over the real number field. The number $(m-1)n-1$ is a minimal typical
rank of $m\times n\times ((m-1)n-1)$ tensors over the real number field. We
show that a typical rank of $m\times n\times ((m-1)n-1)$ tensors over the real
number field is less than or equal to $(m-1)n$ and in particular, $m\times
n\times ((m-1)n-1)$ tensors over the real number field has two typical ranks
$(m-1)n-1, (m-1)n$ if $m\leq \rho(n)$, where $\rho$ is the Hurwitz-Radon
function defined as $\rho(n)=2^b+8c$ for nonnegative integers $a,b,c$ such that
$n=(2a+1)2^{b+4c}$ and $0\leq b<4$.


title: Local criteria for cocommutative Hopf algebras

abstract:
  We prove that a finite-dimensional cocommutative Hopf algebra $H$ is local,
if and only if the subalgebra generated by the first term of its coradical
filtration $H_1$ is local. In particular if $H$ is connected, $H$ is local if
and only if all the primitive elements of $H$ are nilpotent.


title: MHD instabilities in accretion mounds on neutron star binaries

abstract:
  We have numerically solved the Grad-Shafranov equation for axisymmetric
static MHD equilibria of matter confined at the polar cap of neutron stars.
From the equilibrium solutions we explore the stability of the accretion mounds
using the PLUTO MHD code. We find that pressure driven modes disrupt the
equilibria beyond a threshold mound mass, forming dynamic structures, as matter
spreads over the neutron star surface. Our results show that local variation of
magnetic field will significantly affect the shape and nature of the cyclotron
features observed in the spectra of High Mass X-ray Binaries.


title: Classical Space-Times from the S Matrix

abstract:
  We show that classical space-times can be derived directly from the S-matrix
for a theory of massive particles coupled to a massless spin two particle. As
an explicit example we derive the Schwarzchild space-time as a series in $G_N$.
At no point of the derivation is any use made of the Einstein-Hilbert action or
the Einstein equations. The intermediate steps involve only on-shell S-matrix
elements which are generated via BCFW recursion relations and unitarity sewing
techniques. The notion of a space-time metric is only introduced at the end of
the calculation where it is extracted by matching the potential determined by
the S-matrix to the geodesic motion of a test particle. Other static
space-times such as Kerr follow in a similar manner. Furthermore, given that
the procedure is action independent and depends only upon the choice of the
representation of the little group, solutions to Yang-Mills (YM) theory can be
generated in the same fashion. Moreover, the squaring relation between the YM
and gravity three point functions shows that the seeds that generate solutions
in the two theories are algebraically related. From a technical standpoint our
methodology can also be utilized to calculate quantities relevant for the
binary inspiral problem more efficiently than the more traditional Feynman
diagram approach.


title:
Temporal Variability of Waves at the Proton Cyclotron Frequency Upstream
  from Mars: Implications for Mars Distant Hydrogen Exosphere

abstract:
  We report on the temporal variability of the occurrence of waves at the local
proton cyclotron frequency upstream from the Martian bow shock from Mars Global
Surveyor observations during the first aerobraking and science phasing orbit
periods. Observations at high southern latitudes during minimum-to-mean solar
activity show that the wave occurrence rate is significantly higher around
perihelion southern summer solstice and lower around the same hemisphere's
spring and autumn equinoxes. A similar trend is observed in the hydrogen (H)
exospheric density profiles over the Martian South Pole obtained from a model
including UV thermospheric heating effects. In spite of the complexity in the
ion pick-up and plasma wave generation and evolution processes, these results
support the idea that variations in the occurrence of waves could be used to
study the temporal evolution of the distant Martian H corona and its coupling
with the thermosphere at altitudes currently inaccessible to direct
measurements.


title: Graviton Corrections to Vacuum Polarization during Inflation

abstract:
  We use dimensional regularization to compute the one loop quantum
gravitational contribution to the vacuum polarization on de Sitter background.
Adding the appropriate BPHZ counterterms gives a fully renormalized result
which can be used to quantum correct Maxwell's equations. We use the Hartree
approximation to argue that the electric field strengths of photons experience
a secular suppression during inflation.


title:
Exploiting Rydberg Atom Surface Phonon Polariton Coupling for Single
  Photon Subtraction

abstract:
  We investigate a hybrid quantum system that consists of a superatom coupled
to a surface phonon-polariton. We apply this hybrid quantum system to subtract
individual photons from a beam of light. Rydberg atom blockade is used to
attain absorption of a single photon by an atomic microtrap. Surface
phonon-polariton coupling to the superatom then triggers the transfer of the
excitation to a storage state, a single Rydberg atom. The approach utilizes the
interaction between a superatom and a Markovian bath that acts as a controlled
decoherence mechanism to irreversibly project the superatom state into a single
Rydberg atom state that can be read out.


title: Polylogarithms, Multiple Zeta Values and Superstring Amplitudes

abstract:
  A formalism is provided to calculate tree amplitudes in open superstring
theory for any multiplicity at any order in the inverse string tension. We
point out that the underlying world-sheet disk integrals share substantial
properties with color-ordered tree amplitudes in Yang-Mills field theories. In
particular, we closely relate world-sheet integrands of open-string tree
amplitudes to the Kawai-Lewellen-Tye representation of supergravity amplitudes.
This correspondence helps to reduce the singular parts of world-sheet disk
integrals -including their string corrections- to lower-point results. The
remaining regular parts are systematically addressed by polylogarithm
manipulations.


title:
Radar Signal Delay in the Dvali-Gabadadze-Porrati Gravity in the
  Vicinity of the Sun

abstract:
  In this paper we examine the recently introduced Dvali Gabadadze Porrati
gravity model. We use the space time metric in which the local gravitation
source dominates the metric over the contributions from the cosmological flow.
Anticipating ideal possible solar system effects we derive expressions for the
signal time delays in the vicinity of the sun, and for various angles of the
signal approach. We use the corresponding numerical value for the parameter r0
to be equal to 5 Mpc. In the vicinity of the Sun and with theta in the range
-Pi/3 less than equal to theta less than equal to Pi/3, Deltat is equal to
0.0001233 ps. A time signal delay extremely small to measure by todays
technology could be probably measurable in the future years to come, by various
future experiments.


title:
Testing the Metal of Late-Type Kepler Planet Hosts with Iron-Clad
  Methods

abstract:
  It has been shown that F, G, and early K dwarf hosts of Neptune-sized planets
are not preferentially metal-rich. However, it is less clear whether the same
holds for late K and M dwarf planet hosts. We report metallicities of Kepler
targets and candidate transiting planet hosts with effective temperatures below
4500 K. We use new metallicity calibrations to determine [Fe/H] from visible
and near-infrared spectra. We find that the metallicity distribution of late K
and M dwarfs monitored by Kepler is consistent with that of the solar
neighborhood. Further, we show that hosts of Earth- to Neptune-sized planets
have metallicities consistent with those lacking detected planets and rule out
a previously claimed 0.2 dex offset between the two distributions at 6sigma
confidence. We also demonstrate that the metallicities of late K and M dwarfs
hosting multiple detected planets are consistent with those lacking detected
planets. Our results indicate that multiple terrestrial and Neptune-sized
planets can form around late K and M dwarfs with metallicities as low as 0.25
of the solar value. The presence of Neptune-sized planets orbiting such
low-metallicity M dwarfs suggests that accreting planets collect most or all of
the solids from the disk and that the potential cores of giant planets can
readily form around M dwarfs. The paucity of giant planets around M dwarfs
compared to solar-type stars must be due to relatively rapid disk evaporation
or a slower rate of core accretion, rather than insufficient solids to form a
core.


title: Axion Dark Matter and Planck favor non-minimal couplings to gravity

abstract:
  Constraints on inflationary scenarios and isocurvature perturbations have
excluded the simplest and most generic models of dark matter based on QCD
axions. Considering non-minimal kinetic couplings of scalar fields to gravity
substantially changes this picture. The axion can account for the observed dark
matter density avoiding the overproduction of isocurvature fluctuations.
Finally, we show that assuming the same non-minimal kinetic coupling to the
axion (dark matter) and to the standard model Higgs boson (inflaton) provides a
minimal picture of early time cosmology.


title:
Challenge to Macroscopic Probes of Quantum Spacetime Based on
  Noncommutative Geometry

abstract:
  Over the last decade a growing number of quantum-gravity researchers has been
looking for opportunities for the first ever experimental evidence of a
Planck-length quantum property of spacetime. These studies are usually based on
the analysis of some candidate indirect implications of spacetime quantization,
such as a possible curvature of momentum space. Some recent proposals have
raised hope that we might also gain direct experimental access to quantum
properties of spacetime, by finding evidence of limitations to the
measurability of the center-of-mass coordinates of some macroscopic bodies.
However I here observe that the arguments that originally lead to speculating
about spacetime quantization do not apply to the localization of the center of
mass of a macroscopic body. And I also analyze some popular formalizations of
the notion of quantum spacetime, finding that when the quantization of
spacetime is Planckian for the constituent particles then for the composite
macroscopic body the quantization of spacetime is much weaker than Planckian.
These results show that finding evidence of spacetime quantization with studies
of macroscopic bodies is extremely unlikely. And they also raise some
conceptual challenges for theories of mechanics in quantum spacetime, in which
for example free protons and free atoms should feel the effects of spacetime
quantization differently.


title: Line defects in Three dimensional Symmetry Protected Topological Phases

abstract:
  A 3d symmetry protected topological phase, by definition must have symmetry
protected nontrivial boundary states, namely its 2d boundary must be either
gapless or degenerate. In this work we demonstrate that once we couple a 3d SPT
phase to a lattice dynamical Z2 gauge field, in many cases the Z2 vison loop
excitation (line defect) can be viewed as a "1d boundary" of the 3d SPT phase,
and this line defect is guaranteed to have gapless or degenerate spectrum,
which is also protected by the symmetry of the SPT phase.