title: Key classification attack on block ciphers

abstract:
  In this paper, security analysis of block ciphers with key length greater
than block length is proposed. When key length is significantly greater than
block length and the statistical distribution of cipher system is like a
uniform distribution, there are more than one key which map fixed input to
fixed output. If a block cipher designed sufficiently random, it is expected
that the key space can be classified into same classes. Using such classes of
keys, our proposed algorithm would be able to recover the key of block cipher
with complexity O(max(2^n, 2^{k-n}) where n is block length and k is key
length. We applied our algorithm to 2- round KASUMI block cipher as sample
block cipher by using weakness of functions that used in KASUMI.


title: (Contravariant) Koszul duality for DG algebras

abstract:
  A DG algebras $A$ over a field $k$ with $H(A)$ connected and $H_{<0}(A)=0$
has a unique up to isomorphism DG module $K$ with $H(K)\cong k$. It is proved
that if $H(A)$ is degreewise finite, then $RHom_A(?,K): D^{df}_{+}(A)^{op}
\equiv D_{df}^{+}}(RHom_A(K,K))$ is an exact equivalence of derived categories
of DG modules with degreewise finite-dimensional homology. It induces an
equivalences of $D^{df}_{b}(A)^{op}$ and the category of perfect DG
$RHom_A(K,K)$-modules, and vice-versa. Corresponding statements are proved also
when $H(A)$ is simply connected and $H^{<0}(A)=0$.


title:
The instabilities and (anti)-evaporation of Schwarzschild-de Sitter
  black holes in modified gravity

abstract:
  We investigate the future evolution of Nariai black hole which is extremal
limit of Schwarzschild-de Sitter one in modified gravity. The perturbations
equations around Nariai black hole are derived in static and cosmological
patches for general $F(R)$-gravity. The analytical and numerical study of
several realistic $F(R)$-models shows the occurence of rich variety of
scenarios: instabilities, celebrated Hawking evaporation and anti-evaporation
of black hole. The realization of specific scenario depends on the model under
consideration. It is remarkable that the presence of such primordial black
holes at current universe may indicate towards the modified gravity which
supports the anti-evaporation as preferrable model. As some generalization we
extend the study of Nariai black hole evolution to modified Gauss-Bonnet
gravity. The corresponding perturbations equations turn out to be much more
complicated than in the case of $F(R)$ gravity. For specific example of
modified Gauss-Bonnet gravity we demonstrate that Nariai solution maybe stable.


title:
Embedding Riemannian Manifolds by the Heat Kernel of the Connection
  Laplacian

abstract:
  Given a class of closed Riemannian manifolds with prescribed geometric
conditions, we introduce an embedding of the manifolds into $\ell^2$ based on
the heat kernel of the Connection Laplacian associated with the Levi-Civita
connection on the tangent bundle. As a result, we can construct a distance in
this class which leads to a pre-compactness theorem on the class under
consideration.


title: Stress due to Electric and Magnetic fields in Viscoelastic Fluids

abstract:
  A clear understanding of body force densities due to external electromagnetic
fields is necessary to study flow and deformation of materials exposed to the
fields. In this paper, we derive an expression for stress in continua with
viscous and elastic properties in presence of external, static electric or
magnetic fluids. Our derivation follows from fundamental thermodynamic
principles. We demonstrate the soundness of our results by showing that they
reduce to known expressions for Newtonian fluids and elastic solids. We point
out the extra care to be taken while applying these techniques to permanently
polarized or magnetized materials and derive an expression for stress in a
ferro-fluid. Lastly, we derive expressions for ponderomotive forces in several
situations of interest to fluid dynamics and rheology.


title: Optimal Tc for Electron-Doped Cuprate Realized under High Pressure

abstract:
  The race to obtain a higher critical temperature (Tc) in the superconducting
cuprates has been virtually suspended since it was optimized under high
pressure in a hole-doped trilayer cuprate. We report the anomalous increase in
Tc under high pressure for the electron-doped infinite-layer cuprate
Sr0.9La0.1CuO2 in the vicinity of the antiferromagnetic critical point. By the
application of a pressure of 15 GPa, Tc increases to 45 K, which is the highest
temperature among the electron-doped cuprates and ensures unconventional
superconductivity. We describe the electronic phase diagram of Sr1-xLaxCuO2 to
discuss the relation between the antiferromagnetic order and superconductivity.


title: Exciton-related electroluminescence from monolayer MoS2

abstract:
  Excitons in MoS2 dominate the absorption and emission properties of the
two-dimensional system. Here, we study the microscopic origin of the
electroluminescence from monolayer MoS2 fabricated on a heavily p-type doped
silicon substrate. By comparing the photoluminescence and electroluminescence
of a MoS2 diode, direct-exciton and bound-exciton related recombination
processes can be identified. Auger recombination of the exciton-exciton
annihilation of bound exciton emission is observed under a high electron-hole
pair injection rate at room temperature. We expect the direct exciton-exciton
annihilation lifetime to exceed the carrier lifetime, due to the absence of any
noticeable direct exciton saturation. We believe that our method of electrical
injection opens a new route to understand the microscopic nature of the exciton
recombination and facilitate the control of valley and spin excitation in MoS2.


title: Groups in which every non-cyclic subgroup contains its centralizer

abstract:
  We study groups having the property that every non-cyclic subgroup contains
its centralizer. The structure of nilpotent and supersolvable groups in this
class is described. We also classify finite $p$-groups and finite simple groups
with the above defined property.


title: Independent set in categorical products of cographs and splitgraphs

abstract:
  We show that there are polynomial-time algorithms to compute maximum
independent sets in the categorical products of two cographs and two
splitgraphs. We show that the ultimate categorical independence ratio is
computable in polynomial time for cographs.


title: Huneke-Wiegand conjecture and change of rings

abstract:
  Let $R$ be a Cohen-Macaulay local ring of dimension one with a canonical
module $\rm{K_R}$. Let $I$ be a faithful ideal of $R$. We explore the problem
of when $I \otimes_RI^{\vee}$ is torsionfree, where $I^{\vee} =
\operatorname{Hom_R(I, \rm{K_R})}$. We prove that if $R$ has multiplicity at
most $6$, then $I$ is isomorphic to $R$ or $\rm{K_R}$ as an $R$-module, once
$I\otimes_RI^{\vee}$ is torsionfree. This result is applied to monomial ideals
of numerical semigroup rings. A higher dimensional assertion is also discussed.


title:
X-ray quantum optics with M\"ossbauer nuclei embedded in thin film
  cavities

abstract:
  A promising platform for the emerging field of x-ray quantum optics are
M\"ossbauer nuclei embedded in thin film cavities probed by near-resonant x-ray
light, as used in a number of recent experiments. Here, we develop a quantum
optical framework for the description of experimentally relevant settings
involving nuclei embedded in x-ray waveguides. We apply our formalism to two
settings of current experimental interest based on the archetype M\"ossbauer
isotope 57Fe. For present experimental conditions, we derive compact analytical
expressions and show that the alignment of medium magnetization as well as
incident and detection polarization enable the engineering advanced quantum
optical level schemes. The model encompasses non-linear and quantum effects
which could become accessible in future experiments.


title: Relay Selection for Bidirectional AF Relay Network with Outdated CSI

abstract:
  Most previous researches on bidirectional relay selection (RS) typically
assume perfect channel state information (CSI). However, outdated CSI, caused
by the the time-variation of channel, cannot be ignored in the practical
system, and it will deteriorate the performance. In this paper, the effect of
outdated CSI on the performance of bidirectional amplify-and-forward RS is
investigated. The optimal single RS scheme in minimizing the symbol error rate
(SER) is revised by incorporating the outdated channels. The analytical
expressions of end-to-end signal to noise ratio (SNR) and symbol error rate
(SER) are derived in a closed-form, along with the asymptotic SER expression in
high SNR. All the analytical expressions are verified by the Monte-Carlo
simulations. The analytical and the simulation results reveal that once CSI is
outdated, the diversity order degrades to one from full diversity. Furthermore,
a multiple RS scheme is proposed and verified that this scheme is a feasible
solution to compensate the diversity loss caused by outdated CSI.


title: On charged boson stars

abstract:
  We study static, spherically symmetric, self-gravitating systems minimally
coupled to a scalar field with U(1) gauge symmetry: charged boson stars. We
find numerical solutions to the EinsteinMaxwell equations coupled to the
relativistic Klein-Gordon equation. It is shown that bound stable
configurations exist only for values of the coupling constant less than or
equal to a certain critical value. The metric coefficients and the relevant
physical quantities such as the total mass and charge, turn out to be in
general bound functions of the radial coordinate, reaching their maximum values
at a critical value of the scalar field at the origin. We discuss the stability
problem both from the quantitative and qualitative point of view. Taking
properly into account the electromagnetic contribution to the total mass, the
stability issue is faced also following an indication of the binding energy per
particle, verifying then the existence of configurations having positive
binding energy: objects apparently bound can be unstable against small
perturbations, in full analogy with what observed in the mass-radius relation
of neutron stars.


title:
International Co-authorship Relations in the Social Science Citation
  Index: Is Internationalization Leading the Network?

abstract:
  We analyze international co-authorship relations in the Social Science
Citation Index 2011 using all citable items in the DVD-version of this index.
Network statistics indicate four groups of nations: (i) an Asian-Pacific one to
which all Anglo-Saxon nations (including the UK and Ireland) are attributed;
(ii) a continental European one including also the Latin-American countries;
(iii) the Scandinavian nations; and (iv) a community of African nations. Within
the EU-28 (including Croatia), eleven of the EU-15 states have dominant
positions. Collapsing the EU-28 into a single node leads to a bi-polar
structure between the US and EU-28; China is part of the US-pole. We develop an
information-theoretical test to distinguish whether international
collaborations or domestic collaborations prevail; the results are mixed, but
the international dimension is more important than the national one in the
aggregated sets (this was found in both SSCI and SCI). In France, however, the
national distribution is more important than the international one, while the
reverse is true for most European nations in the core group (UK, Germany, the
Netherlands, etc.). Decomposition of the USA in terms of states shows a
similarly mixed result; more US states are domestically oriented in SSCI,
whereas more internationally in SCI. The international networks have grown
during the last decades in addition to the national ones, but not by replacing
them.


title: A note on the $\top$-Stein matrix equation

abstract:
  This note is concerned with the linear matrix equation $X = AX^\top B + C$,
where the operator $(\cdot)^\top$ denotes the transpose ($\top$) of a matrix.
The first part of this paper set forth the necessary and sufficient conditions
for the unique solvability of the solution $X$. The second part of this paper
aims to provide a comprehensive treatment of the relationship between the
theory of the generalized eigenvalue problem and the theory of the linear
matrix equation. In the finally part of this paper starts with a briefly review
of numerical methods for solving the linear matrix equation. Related to the
computed methods, knowledge of the residual is discussed. An expression related
to the backward error of an approximate solution is obtained; it shows that a
small backward error implies a small residual. Just like for the discussion of
linear matrix equations, perturbation bounds for solving the linear matrix
equation are also proposed in this work.


title: Formation of double glass in binary mixtures of anisotropic particles

abstract:
  We study glass transitions in mixtures of elliptic and circular particles in
two dimensions using an orientation-dependent Lennard-Jones potential. Changing
anisotropic parameters of the potential, the size ratio, and the concentration,
we realize double glass, where both the particle positions and orientations are
disordered but still hold mesoscopic order. The ellipses are anchored around
the circular impurities in the homeotropic or planar directions. We examine
slowing-down of rotational and translational time-correlation functions.
Turnover motions of the ellipses are activated more frequently than the
configuration changes, where the latter cause the structural relaxation.


title:
Introduction to effective field theories. 3. Bloch--Nordsieck effective
  theory, HQET

abstract:
  This is a continuation of the lectures [1,2]. In this part we discuss
interaction of electrons with soft photons in QED and Heavy Quark Effective
Theory (HQET).


title:
Scaling relation for the bond length, mass density, and packing order of
  water ice

abstract:
  The packing order of molecules and the distance between adjacent oxygen atoms
(dOO) in water and ice are most basic yet puzzling. Here we present a scaling
solution for this purpose based only on the mass density (gcm-3), (Equation)
where dL is the length ({\AA}) of the O:H van der Waals bond and dH the H-O
polar-covalent bond projecting on the O---O line. Validated by the measured
proton symmetrization of compressed ice, dOO of water and ice, and dOO
expansion at water surface, this solution confirms that the fluctuated,
tetrahedrally-coordinated structure is unique for water ice.


title:
Model Checking Techniques for Verification of an Encryption Scheme for
  Wireless Sensor Networks

abstract:
  In this paper, we deal with the formal verification of an encryption scheme
for Wireless Sensor Networks (WSNs). Especially, we present our first results
on building a framework dedicated to modelling and verification of WSNs
aspects. To achieve our goal, we propose to specify WSNs models written in
Petri nets using Promela constructs in order to verify correctness properties
of them using SPIN Model checker. We first specify in Promela a Petri net
description of an encryption scheme for WSNs that describes its behavior. Then,
correctness properties that express requirements on the system's behavior are
formulated in Linear Temporal Logic (LTL). Finally, SPIN model checker is used
to check if a specific correctness property holds for the model, and, if not,
to provide a counterexample: a computation that does not satisfy this property.
This counterexample will help to detect the source of the eventual problem and
to correct it.


title: Comment on "The entropy of a hole in spacetime"

abstract:
  Balasubramanian, Czech, Chowdhury and de Boer \cite{BCCdB} studied a
"spherical Rindler space" and found that accelerating observers are causally
disconnected from a spherical region located at the origin of Minkowski space.
We show that there is no any horizon of size $R_{0}$ (which is related to the
chosen initial conditions) and the event horizon at $r = 0$ is obtained only
from the two-dimensional ($r, t$) static restriction. Their near-horizon
geometry cancels the time dependence of the original metric and therefore the
approximation used is doubtful.


title:
Inductively coupled superconducting half wavelength resonators as
  persistent current traps for ultracold atoms

abstract:
  A crucial point in the experimental implementation of hybrid quantum systems
consisting of superconducting circuits and atomic ensembles is bringing the two
partners close enough to each other that a strong quantum coherent coupling can
be established. Here, we propose to use the metallization structures of a half
wavelength superconducting coplanar waveguide resonator as a persistent current
trap for ultracold paramagnetic atoms. Trapping atoms with the resonator
structure itself is provided by using short-ended and inductively coupled
resonators instead of capacitively coupled ones as customary in circuit quantum
electrodynamics.We analyze the external quality factor of short-ended coplanar
waveguide resonators and show that it can be easily designed for the desired
regime of quantum circuits. The magnetic field configuration at the resonator
is calculated by means of numerical three-dimensional simulations of the London
equations. We present a way to transport an atomic ensemble into the coplanar
resonator gap where the magnetic field of the cavity mode is maximum. The
configuration allows stable trapping by persistent currents and paves the route
towards strong coupling between atomic clouds and the cavity mode which is
required for cooperative effects and gives the interface between atoms and
circuit quantum electrodynamics.


title: Bipartite entanglement and hypergraph states

abstract:
  We investigate some properties of multipartite entanglement of hypergraph
states in purely hypergraph theoretical terms. We first introduce an approach
for computing the concurrence between two specific qubits of a hypergraph state
by using the so-called Hamming weights of several special subhypergraphs of the
corresponding hypergraph. Then we quantify and characterize bipartite
entanglement between each qubit pair of several special hypergraph states in
terms of the concurrence obtained by using the above approach. Our main results
include that (i) a graph g has a component with the vertex set {i,j} if and
only if the qubit pair labeled by {i,j} of the graph state |g> is entangled;
and (ii) each qubit pair of a special hypergraph state is entangled like the
generalized W state.


title: Deformation method for generalized Abelian Higgs-Chern-Simons models

abstract:
  We present an extension of the deformation method applied to self-dual
solutions of generalized Abelian Higgs-Chern-Simons models. Starting from a
model defined by a potential $V(| \phi |)$ and a non-canonical kinetic term
$\omega(| \phi |) | D_{\mu}\phi |^2$ whose analytical domain wall solutions are
known, we show that this method allows to obtain an uncountable number of new
analytical solutions of new models defined by other functions $\widetilde{V}$
and $\widetilde{\omega}$. We present some examples of deformation functions
leading to new families of models and their associated analytic solutions.


title:
Optical drive of macroscopic mechanical motion by a single two-level
  system

abstract:
  A quantum emitter coupled to a nano-mechanical oscillator is a hybrid system
where a macroscopic degree of freedom is coupled to a purely quantum system.
Recent progress in nanotechnology has led to the realization of such devices by
embedding single artificial atoms like quantum dots or superconducting qubits
into vibrating wires or membranes, opening up new perspectives for quantum
information technologies and for the exploration of the quantum-classical
boundary. In this letter, we show that the quantum emitter can be turned into a
strikingly efficient light-controlled source of mechanical power, by exploiting
constructive interferences of classical phonon fields in the mechanical
oscillator. We show that this mechanism can be used as a novel strategy to
carry out low-background non-destructive single-shot measurement of an
optically active quantum bit state.


title: String networks in Z_N Lotka-Volterra competition models

abstract:
  In this letter we give specific examples of Z_N Lotka-Volterra competition
models leading to the formation of string networks. We show that, in order to
promote coexistence, the species may arrange themselves around regions with a
high number density of empty sites generated by predator-prey interactions
between competing species. These configurations extend into the third dimension
giving rise to string networks. We investigate the corresponding dynamics using
both stochastic and mean field theory simulations, showing that the coarsening
of these string networks follows a scaling law which is analogous to that found
in other physical systems in condensed matter and cosmology.

categories: nlin.AO astro-ph.CO cond-mat.soft physics.bio-ph


title: Enhanced No-Go Theorem for Quantum Position Verification

abstract:
  Based on the instantaneous nonlocal quantum computation (INQC), Buhrman et
al. proposed an excellent attack strategy to quantum position verification
(QPV) protocols in 2011, and showed that, if the colluding adversaries are
allowed to previously share unlimited entangled states, it is impossible to
design an unconditionally secure QPV protocol in the previous model. Here,
trying to overcome this no-go theorem, we find some assumptions in the INQC
attack, which are implicit but essential for the success of this attack, and
present three different QPV protocols where these assumptions are not
satisfied. We show that for the general adversaries, who execute the attack
operations at every common time slot or the time when they detect the arrival
of the challenge signals from the verifiers, secure QPV is achievable. This
implies practically secure QPV can be obtained even if the adversaries is
allowed to share unlimited entanglement previously. Here by "practically" we
mean that in a successful attack the adversaries need launch a new round of
attack on the coming qubits with extremely high frequency so that none of the
possible qubits, which may be sent at random time, will be missed. On the other
side, using such Superdense INQC (SINQC) attack, the adversaries can still
attack the proposed protocols successfully in theory. The particular attack
strategies to our protocols are presented respectively. On this basis, we
demonstrate the impossibility of secure QPV with looser assumptions, i.e. the
enhanced no-go theorem for QPV.


title: Decidability of minimization of fuzzy automata

abstract:
  State minimization is a fundamental problem in automata theory. The problem
is also of great importance in the study of fuzzy automata. However, most work
in the literature considered only state reduction of fuzzy automata, whereas
the state minimization problem is almost untouched for fuzzy automata. Thus in
this paper we focus on the latter problem. Formally, the decision version of
the minimization problem of fuzzy automata is as follows: \begin{itemize}
  \item Given a fuzzy automaton $\mathcal{A}$ and a natural number $k$, that
is, a pair $\langle \mathcal{A}, k\rangle$, is there a $k$-state fuzzy
automaton equivalent to $\mathcal{A}$? \end{itemize} We prove for the first
time that the above problem is decidable for fuzzy automata over totally
ordered lattices. To this end, we first give the concept of systems of fuzzy
polynomial equations and then present a procedure to solve these systems.
Afterwards, we apply the solvability of a system of fuzzy polynomial equations
to the minimization problem mentioned above, obtaining the decidability.
Finally, we point out that the above problem is at least as hard as
PSAPCE-complete.


title: Approximation of holomorphic mappings on 1-convex domains

abstract:
  Let \pi :Z\to X be a holomorphic submersion of a complex manifold Z onto a
complex manifold X and D\Subset X a 1-convex domain with strongly pseudoconvex
boundary. We prove that under certain conditions there always exists a spray of
\pi -sections over \bar{D} which has prescribed core, it fixes the exceptional
set E of D, and is dominating on \bar{D}\setminus E. Each section in this spray
is of class C^k(\bar{D}) and holomorphic on D. As a consequence we obtain
several approximation results for \pi -sections. In particular, we prove that
\pi -sections which are of class C^k(\bar{D}) and holomorphic on D can be
approximated in the C^k(\bar{D}) topology by \pi -sections that are holomorphic
in open neighborhoods of \bar{D}. Under additional assumptions on the
submersion we also get approximation by global holomorphic \pi -sections and
the Oka principle over 1-convex manifolds. We include an application to the
construction of proper holomorphic maps of 1-convex domains into q-convex
manifolds.


title:
Dimensional cross-over of hard parallel cylinders confined on
  cylindrical surfaces

abstract:
  We derive, from the dimensional cross-over criterion, a fundamental-measure
density functional for parallel hard curved rectangles moving on a cylindrical
surface. We derive it from the density functional of circular arcs of length
$\sigma$ with centers of mass located on an external circumference of radius
$R_0$. The latter functional in turns is obtained from the corresponding 2D
functional for a fluid of hard discs of radius $R$ on a flat surface with
centers of mass confined onto a circumference of radius $R_0$. Thus the curved
length of closest approach between two centers of mass of hard discs on this
circumference is $\sigma=2R_0\sin^{-1}(R/R_0)$, the length of the circular
arcs. From the density functional of circular arcs, and by applying a
dimensional expansion procedure to the spatial dimension orthogonal to the
plane of the circumference, we finally obtain the density functional of curved
rectangles of edge-lengths $\sigma$ and $L$. The DF for curved rectangles can
also be obtained by fixing the centers of mass of parallel hard cylinders of
radius $R$ and length $L$ on a cylindrical surface of radius $R_0$. The phase
behavior of a fluid of aligned curved rectangles is obtained by calculating the
free-energy branches of smectic, columnar and crystalline phases for different
values of the ratio $R_0/R$ in the range $1<R_0/R\leq 4$; the smectic phase
turns out to be the most stable except for $R_0/R=4$ where the crystalline
phase becomes reentrant in a small range of packing fractions. When $R_0/R<1$
the transition is absent, since the density functional of curved rectangles
reduces to the 1D Percus functional.


title:
The Araucaria Project. A Distance Determination to the Local Group
  Spiral M33 from Near-Infrared Photometry of Cepheid Variables

abstract:
  Motivated by an amazing range of reported distances to the nearby Local Group
spiral galaxy M33, we have obtained deep near-infrared photometry for 26
long-period Cepheids in this galaxy with the ESO VLT. From the data we
constructed period-luminosity relations in the J and K bands which together
with previous optical VI photometry for the Cepheids by Macri et al. were used
to determine the true distance modulus of M33, and the mean reddening affecting
the Cepheid sample with the multiwavelength fit method developed in the
Araucaria Project. We find a true distance modulus of 24.62 for M33, with a
total uncertainty of +- 0.07 mag which is dominated by the uncertainty on the
photometric zero points in our photometry. The reddening is determined as
E(B-V)=0.19 +- 0.02, in agreement with the value used by the HST Key Project of
Freedman et al. but in some discrepancy with other recent determinations based
on blue supergiant spectroscopy and an O-type eclipsing binary which yielded
lower reddening values. Our derived M33 distance modulus is extremely
insensitive to the adopted reddening law. We show that the possible effects of
metallicity and crowding on our present distance determination are both at the
1-2% level and therefore minor contributors to the total uncertainty of our
distance result for M33.


title:
Quantum Teleportation of Single Qubit Mixed Information State with
  Werner-Like State as Resource

abstract:
  In this paper we extend our recent results for quantum teleportation of
single qubit pure information state using non-maximally entangled pure state
resource [Quantum Inf Process, 11 (2012) 1251] to the case of a general mixed
information state and mixed Werner states resource. Fidelity is found dependent
on information state in general. We minimize it over all possible information
states and maximize it over possible unitary transformations which can be done
by the receiver to obtain a value dependent on purity of information state and
mixing parameter of Werner states. For pure information state, this value of
fidelity is independent of information and for mixed information states it is
less than unity even for perfect entangled resource. The latter result is in
contrast to the case of pure states.


title: The ultimate rank of tropical matrices

abstract:
  A tropical matrix is a matrix defined over the max-plus semiring. For such
matrices, there exist several non-coinciding notions of rank: the row rank, the
column rank, the Schein/Barvinok rank, the Kapranov rank, or the tropical rank,
among others. In the present paper, we show that there exists a natural notion
of ultimate rank for the powers of a tropical matrix, which does not depend on
the underlying notion of rank. Furthermore, we provide a simple formula for the
ultimate rank of a matrix which can therefore be computed in polynomial time.
Then we turn our attention to finitely generated semigroups of matrices, for
which our notion of ultimate rank is generalized naturally. We provide both
combinatorial and geometric characterizations of semigroups having maximal
ultimate rank. As a byproduct, we obtain a polynomial algorithm to decide if
the ultimate rank of a finitely generated semigroup is maximal.


title:
Sub-millimeter nuclear medical imaging with high sensitivity in positron
  emission tomography using beta-gamma coincidences

abstract:
  We present a nuclear medical imaging technique, employing triple-gamma
trajectory intersections from beta^+ - gamma coincidences, able to reach
sub-millimeter spatial resolution in 3 dimensions with a reduced requirement of
reconstructed intersections per voxel compared to a conventional PET
reconstruction analysis. This '$\gamma$-PET' technique draws on specific beta^+
- decaying isotopes, simultaneously emitting an additional photon. Exploiting
the triple coincidence between the positron annihilation and the third photon,
it is possible to separate the reconstructed 'true' events from background. In
order to characterize this technique, Monte-Carlo simulations and image
reconstructions have been performed. The achievable spatial resolution has been
found to reach ca. 0.4 mm (FWHM) in each direction for the visualization of a
22Na point source. Only 40 intersections are sufficient for a reliable
sub-millimeter image reconstruction of a point source embedded in a scattering
volume of water inside a voxel volume of about 1 mm^3 ('high-resolution mode').
Moreover, starting with an injected activity of 400 MBq for ^76Br, the same
number of only about 40 reconstructed intersections are needed in case of a
larger voxel volume of 2 x 2 x 3~mm^3 ('high-sensitivity mode'). Requiring such
a low number of reconstructed events significantly reduces the required
acquisition time for image reconstruction (in the above case to about 140 s)
and thus may open up the perspective for a quasi real-time imaging.


title:
Hardy-Sobolev inequalities for vector fields and canceling linear
  differential operators

abstract:
  Given a homogeneous k-th order differential operator $A (D)$ on
$\mathbb{R}^n$ between two finite dimensional spaces, we establish the Hardy
inequality $$\int_{\mathbb{R}^n} \frac{\lvert D^{k-1}u\rvert}{\lvert x \rvert}
\,\mathrm{d} x \leq C \int_{\mathbb{R}^n} \lvert A(D)u\rvert $$ and the Sobolev
inequality $$\lVert D^{k-n} u\rVert_{L^{\infty}(\mathbb{R}^n)}\leq C
\int_{\mathbb{R}^n} \lvert A(D)u\rvert $$ when $A(D)$ is elliptic and satisfies
a recently introduced cancellation property. We also study the necessity of
these two conditions.


title: Self-Stabilizing Paxos

abstract:
  We present the first self-stabilizing consensus and replicated state machine
for asynchronous message passing systems. The scheme does not require that all
participants make a certain number of steps prior to reaching a practically
infinite execution where the replicated state machine exhibits the desired
behavior. In other words, the system reaches a configuration from which it
operates according to the specified requirements of the replicated
state-machine, for a long enough execution regarding all practical
considerations.


title:
Moderate stem cell telomere shortening rate postpones cancer onset in
  stochastic model

abstract:
  Mammalian cells are restricted from proliferating indefinitely. Telomeres at
the end of each chromosome are shortened at cell division and, when they reach
a critical length, the cell will enter permanent cell cycle arrest - a state
known as senescence. This mechanism is thought to be tumor suppressing, as it
helps prevent precancerous cells from dividing uncontrollably.
  Stem cells express the enzyme telomerase, which elongates the telomeres,
thereby postponing senescence. However, unlike germ cells and most types of
cancer cells, stem cells only express telomerase at levels insufficient to
fully maintain the length of their telomeres leading to a slow decline in
proliferation potential. It is not yet fully understood how this decline
influences the risk of cancer and the longevity of the organism. We here
develop a stochastic model to explore the role of telomere dynamics in relation
to both senescence and cancer. The model describes the accumulation of
cancerous mutations in a multicellular organism and creates a coherent
theoretical framework for interpreting the results of several recent
experiments on telomerase regulation. We demonstrate that the longest average
cancer free life span before cancer onset is obtained when stem cells start
with relatively long telomeres that are shortened at a steady rate at cell
division. Furthermore, the risk of cancer early in life can be reduced by
having a short initial telomere length. Finally, our model suggests that
evolution will favour a shorter than optimal average cancer free life span in
order to postpone cancer onset until late in life.


title:
Effects of Lorentz violation through the $\gamma e\to W\nu_e$ process in
  the Standard Model Extension

abstract:
  Physics beyond the Fermi scale could show up through deviations of the gauge
couplings predicted by the electroweak Yang-Mills sector. This possibility is
explored in the context of the International Linear Collider (ILC) through the
helicity amplitudes for the gamma e -> W nu_e reaction to which contributes the
trilinear WWgamma coupling. The new physics effects on this vertex are
parametrized in a model-independent fashion through an effective electroweak
Yang-Mills sector, which is constructed by considering two essentially
different sources of new physics. In one scenario, Lorentz violation will be
considered exclusively as the source of new physics effects. This type of new
physics is considered in an extension of the Standard Model that is known as
the Standard Model Extension (SME), which is an effective field theory that
contemplates CPT and Lorentz violation in a model-independent fashion. Any
source of new physics that respects the Lorentz symmetry, will be considered
within the general context of the well known Conventional Effective Standard
Model (CESM) extension. Both the SME and the CESM descriptions include gauge
invariant operators of dimension higher than four, which, in general, transform
as Lorentz tensors of rank higher than zero. Whereas in the former theory
observer Lorentz invariants are constructed by contracting these operators with
constant Lorentz tensors, in the latter the corresponding Lorentz invariant
interactions are obtained contracting such operators with products of the
metric tensor. We focus our study on the possibility of experimentally
distinguish both types of new physics effects on the WWgamma vertex. It is
found that for a new physics scale of the same order of magnitude and under
determined circumstances, both types of new physics effects will be clearly
distinguished.


title: Nonperturbative region of effective strong coupling

abstract:
  In the framework of Poincar\'{e} covariant quark model the behavior of
running coupling constant $\alpha_{s}\left(Q^{2}\right)$ is considered in $Q <
1 \mbox{GeV}$ region. An analysis was carried out for pseudoscalar and vector
mesons with lepton decay constants, masses (obtained from model dependent) and
nucleon spin rules required to match their experimental counterparts. Possible
behavior of $\alpha_{s}$ with
$\alpha_{\mathrm{crit.}}=\alpha_{s}\left(Q^{2}=0\right) \sim 0.65-0.72$ in the
case of a frozen regime, which follows from experimental values of lepton decay
constant, masses and nucleon spin rules are discussed.


title:
Characterization of a Two Weight Inequality for Multilinear Fractional
  Maximal Operators

abstract:
  In this paper, we study the characterization of two weight inequality for
multilinear fractional maximal operators. We give a multilinear analogue of
Sawyer's two weight test condition.


title: Dynamic Covariance Models for Multivariate Financial Time Series

abstract:
  The accurate prediction of time-changing covariances is an important problem
in the modeling of multivariate financial data. However, some of the most
popular models suffer from a) overfitting problems and multiple local optima,
b) failure to capture shifts in market conditions and c) large computational
costs. To address these problems we introduce a novel dynamic model for
time-changing covariances. Over-fitting and local optima are avoided by
following a Bayesian approach instead of computing point estimates. Changes in
market conditions are captured by assuming a diffusion process in parameter
values, and finally computationally efficient and scalable inference is
performed using particle filters. Experiments with financial data show
excellent performance of the proposed method with respect to current standard
models.


title: Casimir Friction Between Dense Polarizable Media

abstract:
  The present paper - a continuation of our recent series of papers on Casimir
friction for a pair of particles at low relative particle velocity - extends
the analysis so as to include dense media. The situation becomes in this case
more complex due to induced dipolar correlations, both within planes, and
between planes. We show that the structure of the problem can be simplified by
regarding the two half-planes as a generalized version of a pair of particles.
It turns out that macroscopic parameters such as permittivity suffice to
describe the friction also in the finite density case. The expression for the
friction force per unit surface area becomes mathematically well-defined and
finite at finite temperature. We give numerical estimates, and compare them
with those obtained earlier by Pendry (1997) and by Volokitin and Persson
(2007). We also show in an appendix how the statistical methods that we are
using, correspond to the field theoretical methods more commonly in use.


title: On the equivalence of several definitions of compact infra-solvmanifolds

abstract:
  We show the equivalence of several definitions of compact infra-solvmanifolds
that appear in various math literatures.


title: The Cantor's First Diagonal Formalized and Extended

abstract:
  We examinate, formalize and extend the reasoning behind the Cantor's first
diagonal argument, obtaining a simple closed-form expression for a bijection
between $\mathbb{N}^k$ and $\mathbb{N}$.


title: Dilations and constrained algebras

abstract:
  It is well known that unital contractive representations of the disk algebra
are completely contractive. Let A denote the subalgebra of the disk algebra
consisting of those functions f whose first derivative vanishes at 0. We prove
that there are unital contractive representations of A which are not completely
contractive, and furthermore provide a Kaiser and Varopoulos inspired example
for A and present a characterization of those contractive representations of A
which are completely contractive. In the positive direction, for the algebra of
rational functions with poles off the distinguished variety V in the bidisk
determined by (z-w)(z+w)=0, unital contractive representations are completely
contractive.


title: Likelihood-free Simulation-based Optimal Design

abstract:
  Simulation-based optimal design techniques are a convenient tool for solving
a particular class of optimal design problems. The goal is to find the optimal
configuration of factor settings with respect to an expected utility criterion.
This criterion depends on the specified probability model for the data and on
the assumed prior distribution for the model parameters. We develop new
simulation-based optimal design methods which incorporate likelihood-free
approaches and utilize them in novel applications.
  Most simulation-based design strategies solve the intractable expected
utility integral at a specific design point by using Monte Carlo simulations
from the probability model. Optimizing the criterion over the design points is
carried out in a separate step. M\"uller (1999) introduces an MCMC algorithm
which simultaneously addresses the simulation as well as the optimization
problem. In principle, the optimal design can be found by detecting the utility
mode of the sampled design points. Several improvements have been suggested to
facilitate this task for multidimensional design problems (see e.g. Amzal et
al. 2006).
  We aim to extend this simulation-based design methodology to design problems
where the likelihood of the probability model is of an unknown analytical form
but it is possible to simulate from the probability model. We further assume
that prior observations are available. In such a setting it is seems natural to
employ approximate Bayesian computation (ABC) techniques in order to be able to
simulate from the conditional probability model. We provide a thorough review
of adjacent literature and we investigate the benefits and the limitations of
our design methodology for a particular paradigmatic example.


title:
Conditional Random Fields, Planted Constraint Satisfaction, and Entropy
  Concentration

abstract:
  This paper studies a class of probabilistic models on graphs, where edge
variables depend on incident node variables through a fixed probability kernel.
The class includes planted con- straint satisfaction problems (CSPs), as well
as more general structures motivated by coding and community clustering
problems. It is shown that under mild assumptions on the kernel and for sparse
random graphs, the conditional entropy of the node variables given the edge
variables concentrates around a deterministic threshold. This implies in
particular the concentration of the number of solutions in a broad class of
planted CSPs, the existence of a threshold function for the disassortative
stochastic block model, and the proof of a conjecture on parity check codes. It
also establishes new connections among coding, clustering and satisfiability.


title:
Entropy criteria and stability of extreme shocks: a remark on a paper of
  Leger and Vasseur

abstract:
  We show that a relative entropy condition recently shown by Leger and Vasseur
to imply uniqueness and stable $L^2$ dependence on initial data of Lax 1- or
$n$-shock solutions of an $n\times n$ system of hyperbolic conservation laws
with convex entropy implies Lopatinski stability in the sense of Majda. This
means in particular that Leger and Vasseur's relative entropy condition
represents a considerable improvement over the standard entropy condition of
decreasing shock strength and increasing entropy along forward Hugoniot curves,
which, in a recent example exhibited by Barker, Freist\"uhler and Zumbrun, was
shown to fail to imply Lopatinski stability, even for systems with convex
entropy. This observation bears also on the parallel question of existence, at
least for small $BV$ or $H^s$ perturbations


title: Moduli of map germs, Thom polynomials and the Green-Griffiths conjecture

abstract:
  This survey paper is based on my IMPANGA lectures given in the Banach Center,
Warsaw in January 2011. We study the moduli of holomorphic map germs from the
complex line into complex compact manifolds with applications in global
singularity theory and the theory of hyperbolic algebraic varieties.


title:
On the maximum rank of Toeplitz block matrices of blocks of a given
  pattern

abstract:
  We show that the maximum rank of block lower triangular Toeplitz block
matrices equals their term rank if the blocks fulfill a structural condition,
i.e., only the locations but not the values of their nonzeros are fixed.


title: Excitonic Collapse in Semiconducting Transition Metal Dichalcogenides

abstract:
  Semiconducting transition metal dichalcogenides (STMDC) are two-dimensional
(2D) crystals characterized by electron volt size band gaps, spin-orbit
coupling (SOC), and d-orbital character of its valence and conduction bands. We
show that these materials carry unique exciton quasiparticles (electron-hole
bound states) with energy within the gap but which can ``collapse'' in the
strong coupling regime by merging into the band structure continuum. The
exciton collapse seems to be a generic effect in these 2D crystals.


title: Soliton in a Well. Dynamics and Tunneling

abstract:
  We derive the leading order radiation through tunneling of an oscillating
soliton in a well. We use the hydrodynamic formulation with a rigorous control
of the errors for finite times.


title:
A Novel Parametric Bound for Information Retrieval from Black Hole
  Radiation

abstract: This paper has been withdrawn by author.


title:
Operation of a titanium nitride superconducting microresonator detector
  in the nonlinear regime

abstract:
  If driven sufficiently strongly, superconducting microresonators exhibit
nonlinear behavior including response bifurcation. This behavior can arise from
a variety of physical mechanisms including heating effects, grain boundaries or
weak links, vortex penetration, or through the intrinsic nonlinearity of the
kinetic inductance. Although microresonators used for photon detection are
usually driven fairly hard in order to optimize their sensitivity, most
experiments to date have not explored detector performance beyond the onset of
bifurcation. Here we present measurements of a lumped-element superconducting
microresonator designed for use as a far-infrared detector and operated deep
into the nonlinear regime. The 1 GHz resonator was fabricated from a 22 nm
thick titanium nitride film with a critical temperature of 2 K and a
normal-state resistivity of $100\, \mu \Omega\,$cm. We measured the response of
the device when illuminated with 6.4 pW optical loading using microwave readout
powers that ranged from the low-power, linear regime to 18 dB beyond the onset
of bifurcation. Over this entire range, the nonlinear behavior is well
described by a nonlinear kinetic inductance. The best noise-equivalent power of
$2 \times 10^{-16}$ W/Hz$^{1/2}$ at 10 Hz was measured at the highest readout
power, and represents a $\sim$10 fold improvement compared with operating below
the onset of bifurcation.


title: Dynamics of a Continuous Piecewise Affine Map of the Square

abstract:
  We present a one-parameter family of continuous, piecewise affine, area
preserving maps of the square, which are inspired by a dynamical system in game
theory. Interested in the coexistence of stochastic and (quasi-)periodic
behaviour, we investigate invariant annuli separated by invariant circles. For
certain parameter values, we explicitly construct invariant circles both of
rational and irrational rotation numbers, and present numerical experiments of
the dynamics on the annuli bounded by these circles.


title:
Statistical modelling of summary values leads to accurate Approximate
  Bayesian Computations

abstract:
  Approximate Bayesian Computation (ABC) methods rely on asymptotic arguments,
implying that parameter inference can be systematically biased even when
sufficient statistics are available. We propose to construct the ABC
accept/reject step from decision theoretic arguments on a suitable auxiliary
space. This framework, referred to as ABC*, fully specifies which test
statistics to use, how to combine them, how to set the tolerances and how long
to simulate in order to obtain accuracy properties on the auxiliary space. Akin
to maximum-likelihood indirect inference, regularity conditions establish when
the ABC* approximation to the posterior density is accurate on the original
parameter space in terms of the Kullback-Leibler divergence and the maximum a
posteriori point estimate. Fundamentally, escaping asymptotic arguments
requires knowledge of the distribution of test statistics, which we obtain
through modelling the distribution of summary values, data points on a summary
level. Synthetic examples and an application to time series data of influenza A
(H3N2) infections in the Netherlands illustrate ABC* in action.


title: Augmented base loci and restricted volumes on normal varieties

abstract:
  We extend to normal projective varieties defined over an arbitrary
algebraically closed field a result of Ein, Lazarsfeld, Musta\c{t}\u{a},
Nakamaye and Popa characterizing the augmented base locus (aka non-ample locus)
of a line bundle on a smooth projective complex variety as the union of
subvarieties on which the restricted volume vanishes. We also give a proof of
the folklore fact that the complement of the augmented base locus is the
largest open subset on which the Kodaira map defined by large and divisible
multiples of the line bundle is an isomorphism.


title: Josephson Effects in a Bose-Einstein Condensate of Magnons

abstract:
  A phenomenological theory is developed, that accounts for the collective
dynamics of a Bose-Einstein condensate of magnons. In terms of such description
we discuss the nature of spontaneous macroscopic interference between magnon
clouds, highlighting the close relation between such effects and the well known
Josephson effects. Using those ideas we present a detailed calculation of the
Josephson oscillations between two magnon clouds, spatially separated in a
magnonic Josephson junction.


title:
Application of Geometric measure Theory in Continuum Mechanics: The
  Configuration Space, Principle of Virtual Power and Cauchy's Stress Theory
  for Rough Bodies

abstract:
  In this work, the principles of Homological Integration Theory are applied to
the mathematical formulation of continuum mechanics. A central guideline in the
currently acceptable formulation of continuum mechanics is that an admissible
body is represented by a set of finite perimeter. The proposed framework is
shown to enable the inclusion of a class of generalized bodies for which a
corresponding stress theory is properly formulated and a generalized principle
of virtual power is presented.


title:
Analogs of generalized resolvents of relations generated by pair of
  differential operator expressions one of which depends on spectral parameter
  in nonlinear manner

abstract:
  For the relations generated by pair of differential operator expressions one
of which depends on the spectral parameter in the Nevanlinna manner we
construct analogs of the generalized resolvents which are integro-differential
operators.


title: Upwards Closed Dependencies in Team Semantics

abstract:
  We prove that adding upwards closed first-order dependency atoms to
first-order logic with team semantics does not increase its expressive power
(with respect to sentences), and that the same remains true if we also add
constancy atoms. As a consequence, the negations of functional dependence,
conditional independence, inclusion and exclusion atoms can all be added to
first-order logic without increasing its expressive power.
  Furthermore, we define a class of bounded upwards closed dependencies and we
prove that unbounded dependencies cannot be defined in terms of bounded ones.


title: Free Semidefinite Representation of Matrix Power Functions

abstract:
  Consider the matrix power function X^p defined over the cone of positive
definite matrices S^{n}_{++}. It is known that X^p is convex over S^{n}_{++} if
p is in [-1,0] or [1,2] and X^p is concave over S^{n}_{++} if p is in [0,1]. We
show that the hypograph of X^p admits a free semidefinite representation if p
in [0,1] is rational, and the epigraph of X^p admits a free semidefinite
representation if p in [-1,0] or [1,2] is rational.


title:
Extracting information from a qubit by multiple observers: Toward a
  theory of sequential state discrimination

abstract:
  We discuss sequential unambiguous state-discrimination measurements performed
on the same qubit. Alice prepares a qubit in one of two possible states. The
qubit is first sent to Bob, who measures it, and then on to Charlie, who also
measures it. The object in both cases is to determine which state Alice sent.
In an unambiguous state discrimination measurement, we never make a mistake,
i.e. misidentify the state, but the measurement may fail, in which case we gain
no information about which state was sent. We find that there is a nonzero
probability for both Bob and Charlie to identify the state, and we maximize
this probability. The probability that Charlie's measurement succeeds depends
on how much information about the state Alice sent is left in the qubit after
Bob's measurement, and this information can be quantified by the overlap
between the two possible states in which Bob's measurement leaves the qubit.
This paper is a first step toward developing a theory of nondestructive
sequential quantum measurements, which could be useful in quantum communication
schemes.


title: A new formulation of the Teichm\"uller TQFT

abstract:
  By using the Weil-Gel'fand-Zak transform of Faddeev's quantum dilogarithm, we
propose a new state-integral model for the Teichm\"uller TQFT, where the circle
valued state variables live on the edges of oriented leveled shaped
triangulations.


title: On the boundedness of Bernoulli processes

abstract:
  We present a positive solution to the so-called Bernoulli Conjecture
concerning the characterization of sample boundedness of Bernoulli processes.
We also discuss some applications and related open problems.


title: What is ... Equivariant Cohomology?

abstract:
  When a torus acts on a compact oriented manifold with isolated fixed points,
the equivariant localization formula of Atiyah--Bott--Berline--Vergne converts
the integral of an equivariantly closed form to a finite sum over the fixed
points, providing a powerful tool for computing integrals on a manifold. This
article seeks to give an accessible exposition of the equivariant localization
formula.


title: Kac-Moody symmetric spaces of Euclidean type

abstract:
  We investigate in detail the class of Euclidean affine Kac-Moody symmetric
spaces and their orthogonal symmetric affine Kac-Moody algebras (OSAKAs). These
spaces are the only class of Kac-Moody symmetric spaces, that is not directly
derived from affine Kac-Moody algebras in the classical sense.


title: Holomorphic completions of affine Kac-Moody groups

abstract:
  We construct holomorphic loop groups and their associated affine Kac-Moody
groups and prove that they are tame Fr\'echet manifolds. These results form the
functional analytic basis for the theory of affine Kac-Moody symmetric spaces,
presented first in the authors thesis. Our approach also solves completely the
problem of complexification of loop groups; it allows a complete description of
complex Kac-Moody groups and their non-compact real forms.


title: The Method of Alternating Relaxed Projections for two nonconvex sets

abstract:
  The Method of Alternating Projections (MAP), a classical algorithm for
solving feasibility prob- lems, has recently been intensely studied for
nonconvex sets. However, intrinsically available are only local convergence
results: convergence occurs if the starting point is not too far away from
solutions to avoid getting trapped in certain regions. Instead of taking full
projection steps, it can be advantageous to underrelax, i.e., to move only part
way towards the constraint set, in order to enlarge the regions of convergence.
In this paper, we thus systematically study the Method of Alternating Relaxed
Projections (MARP) for two (possibly nonconvex) sets. Complementing our recent
work on MAP, we es- tablish local linear convergence results for the MARP.
Several examples illustrate our analysis.


title: On a perturbation method for stochastic parabolic PDE

abstract:
  In the article we address two issues related to the perturbation method
introduced by Zhang and Lu, and applied to solving linear stochastic parabolic
PDE. Those issues are: the construction of the perturbation series, and its
convergence.


title: Blockwise SURE Shrinkage for Non-Local Means

abstract:
  In this letter, we investigate the shrinkage problem for the non-local means
(NLM) image denoising. In particular, we derive the closed-form of the optimal
blockwise shrinkage for NLM that minimizes the Stein's unbiased risk estimator
(SURE). We also propose a constant complexity algorithm allowing fast blockwise
shrinkage. Simulation results show that the proposed blockwise shrinkage method
improves NLM performance in attaining higher peak signal noise ratio (PSNR) and
structural similarity index (SSIM), and makes NLM more robust against parameter
changes. Similar ideas can be applicable to other patchwise image denoising
techniques.


title: Modeling self-sustained activity cascades in socio-technical networks

abstract:
  The ability to understand and eventually predict the emergence of information
and activation cascades in social networks is core to complex socio-technical
systems research. However, the complexity of social interactions makes this a
challenging enterprise. Previous works on cascade models assume that the
emergence of this collective phenomenon is related to the activity observed in
the local neighborhood of individuals, but do not consider what determines the
willingness to spread information in a time-varying process. Here we present a
mechanistic model that accounts for the temporal evolution of the individual
state in a simplified setup. We model the activity of the individuals as a
complex network of interacting integrate-and-fire oscillators. The model
reproduces the statistical characteristics of the cascades in real systems, and
provides a framework to study time-evolution of cascades in a state-dependent
activity scenario.


title:
Solution of linear equations and inequalities in idempotent vector
  spaces

abstract:
  Linear vector equations and inequalities are considered defined in terms of
idempotent mathematics. To solve the equations, we apply an approach that is
based on the analysis of distances between vectors in idempotent vector spaces.
The approach reduces the solution of the equation to that of an optimization
problem in the idempotent algebra setting. Based on the approach, existence and
uniqueness conditions are established for the solution of equations, and a
general solution to both linear equations and inequalities are given. Finally,
a problem of simultaneous solution of equations and inequalities is also
considered.


title: Mixtures of Skew-t Factor Analyzers

abstract:
  In this paper, we introduce a mixture of skew-t factor analyzers as well as a
family of mixture models based thereon. The mixture of skew-t distributions
model that we use arises as a limiting case of the mixture of generalized
hyperbolic distributions. Like their Gaussian and t-distribution analogues, our
mixture of skew-t factor analyzers are very well-suited to the model-based
clustering of high-dimensional data. Imposing constraints on components of the
decomposed covariance parameter results in the development of eight flexible
models. The alternating expectation-conditional maximization algorithm is used
for model parameter estimation and the Bayesian information criterion is used
for model selection. The models are applied to both real and simulated data,
giving superior clustering results compared to a well-established family of
Gaussian mixture models.


title: Cellular structure for the Herzog--Takayama Resolution

abstract:
  Herzog and Takayama constructed explicit resolutions for the class of so
called ideals with a regular linear quotient. This class contains all matroidal
and stable ideals. The resolutions of matroidal and stable ideals are known to
be cellular. In this note we show that the Herzog--Takayama resolution is also
cellular.


title:
Moments Finiteness Problem and Center Problem for Ordinary Differential
  Equations

abstract:
  We study the moments finiteness problem for the class of Lipschitz maps $F:
[a,b]\rightarrow\mathbb R^n$ with images in a compact Lipschitz triangulable
curve $\Gamma$. We apply the obtained results to the center problem for ODEs
describing in some cases (including equations with analytic coefficients) the
set of universal centers of such equations by vanishing of finitely many
moments from their coefficients.


title:
On generalized Robertson-Walker spacetimes satisfying some curvature
  condition

abstract:
  We give necessary and sufficient conditions for warped product manifolds with
1-dimensional base, and in particular, for generalized Robertson-Walker
spacetimes, to satisfy some generalized Einstein metric condition. We also
construct suitable examples of such manifolds. They are quasi-Einstein or not.


title: Cookie Monster Devours Naccis

abstract:
  In 2002, Cookie Monster appeared in The Inquisitive Problem Solver. The
hungry monster wants to empty a set of jars filled with various numbers of
cookies. On each of his moves, he may choose any subset of jars and take the
same number of cookies from each of those jars.
  The Cookie Monster number is the minimum number of moves Cookie Monster must
use to empty all of the jars. This number depends on the initial distribution
of cookies in the jars.
  We discuss bounds of the Cookie Monster number and explicitly find the Cookie
Monster number for Fibonacci, Tribonacci and other nacci sequences.


title:
Quasinormal ringing of Kerr black holes. II. Excitation by particles
  falling radially with arbitrary energy

abstract:
  The analytical understanding of quasinormal mode ringing requires an accurate
knowledge of the Green's function describing the response of the black hole to
external perturbations. We carry out a comprehensive study of quasinormal mode
excitation for Kerr black holes. Relying on the formalism developed by Mano,
Suzuki and Takasugi, we improve and extend previous calculations of the
quasinormal mode residues in the complex frequency plane ("excitation factors"
B_q). Using these results we compute the "excitation coefficients" C_q
(essentially the mode amplitudes) in the special case where the source of the
perturbations is a particle falling into the black hole along the symmetry
axis. We compare this calculation with numerical integrations of the
perturbation equations, and we show quantitatively how the addition of higher
overtones improves the agreement with the numerical waveforms. Our results
should find applications in models of the ringdown stage and in the
construction of semianalytical template banks for gravitational-wave detectors,
especially for binaries with large mass ratios and/or fast-spinning black
holes.


title:
Smoothing of commutators for a H\"ormander class of bilinear
  pseudodifferential operators

abstract:
  Commutators of bilinear pseudodifferential operators with symbols in the
H\"ormander class BS_{1, 0}^1 and multiplication by Lipschitz functions are
shown to be bilinear Calder\'on-Zygmund operators. A connection with a notion
of compactness in the bilinear setting for the iteration of the commutators is
also made.


title: Connected Domatic Packings in Node-capacitated Graphs

abstract:
  A set of vertices in a graph is a dominating set if every vertex outside the
set has a neighbor in the set. A dominating set is connected if the subgraph
induced by its vertices is connected. The connected domatic partition problem
asks for a partition of the nodes into connected dominating sets. The connected
domatic number of a graph is the size of a largest connected domatic partition
and it is a well-studied graph parameter with applications in the design of
wireless networks. In this note, we consider the fractional counterpart of the
connected domatic partition problem in \emph{node-capacitated} graphs. Let $n$
be the number of nodes in the graph and let $k$ be the minimum capacity of a
node separator in $G$. Fractionally we can pack at most $k$ connected
dominating sets subject to the capacities on the nodes, and our algorithms
construct packings whose sizes are proportional to $k$. Some of our main
contributions are the following: \begin{itemize} \item An algorithm for
constructing a fractional connected domatic packing of size $\Omega(k)$ for
node-capacitated planar and minor-closed families of graphs. \item An algorithm
for constructing a fractional connected domatic packing of size $\Omega(k /
\ln{n})$ for node-capacitated general graphs. \end{itemize}


title: The distance to the young open cluster Westerlund 2

abstract:
  A new X-ray, {\it UBVR}$I_c$, and {\it JHK$s$} study of the young cluster
Westerlund 2 was undertaken to resolve discrepancies tied to the cluster's
distance. Existing spectroscopic observations for bright cluster members and
new multi-band photometry imply a reddening relation towards Westerlund~2
described by $E_{U-B}/E_{B-V}=0.63 + 0.02\;E_{B-V}$. Variable-extinction
analyses for Westerlund~2 and nearby IC 2581 based upon spectroscopic distance
moduli and ZAMS fitting yield values of $R_V=A_V/E_{B-V}=3.88\pm0.18$ and
$3.77\pm0.19$, respectively, and confirm prior assertions that anomalous
interstellar extinction is widespread throughout Carina (e.g., Turner 2012).
The results were confirmed by applying the color difference method to {\it
UBVR$I_c$JH$K_s$} data for 19 spectroscopically-observed cluster members,
yielding $R_V=3.85\pm0.07$. The derived distance to Westerlund~2 of
$d=2.85\pm0.43$ kpc places the cluster on the far side of the Carina spiral
arm. The cluster's age is no more than $\tau \sim2\times10^6$ yr as inferred
from the cluster's brightest stars and an X-ray (Chandra) cleaned analysis of
its pre-main-sequence demographic. Four Wolf-Rayet stars in the cluster core
and surrounding corona (WR20a, WR20b, WR20c, and WR20aa) are likely cluster
members, and their inferred luminosities are consistent with those of other
late-WN stars in open clusters. The color-magnitude diagram for Westerlund~2
also displays a gap at spectral type B0.5 V with associated color spread at
higher and lower absolute magnitudes that might be linked to close binary
mergers. Such features, in conjunction with the evidence for mass loss from the
WR stars, may help to explain the high flux of $\gamma$ rays, cosmic rays, and
X-rays from the direction towards Westerlund~2.


title: Representation field for orders of small ranks

abstract:
  A representation field for a non-maximal order H in a central simple algebra
A is a subfield of the spinor class field of maximal orders which determines
the set of spinor genera of maximal orders representing H. In our previous work
we have proved the existence of the representation field for several important
families of suborders, like commutative orders, while we have also found
examples where the representation field fails to exist. In this article, we
prove that the representation field is defined for any order H of rank 7 or
lower. The same technique yields the existence of representation fields for any
order in an algebra whose semi-simple reduction is commutative. We also
construct a rank-8 order whose representation field is not defined.


title:
Performance Evaluation of Enhanced Interior Gateway Routing Protocol in
  IPv6 Network

abstract:
  With the explosive growth in communication and network technologies, there is
a great demand of IPv6 addressing scheme. However, the modern operating systems
has option for this and with the development of IPv6 which removes the
limitations imposed by IPv4 and provides the large number of address space. In
this paper, authors have considered the Enhanced Interior Gateway Routing
Protocol and presented a scenario for its performance evaluation in IPv6
networks and obtained results are highly considerable for the short distance of
communication and don't represent any problem of performance degradation while
sending or receiving the data.


title: The Boson peak in supercooled water

abstract:
  We perform extensive molecular dynamics simulations of the TIP4P/2005 model
of water to investigate the origin of the Boson peak reported in experiments on
supercooled water in nanoconfined pores, and in hydration water around
proteins. We find that the onset of the Boson peak in supercooled bulk water
coincides with the crossover to a predominantly low-density-like liquid below
the Widom line $T_W$. The frequency and onset temperature of the Boson peak in
our simulations of bulk water agree well with the results from experiments on
nanoconfined water. Our results suggest that the Boson peak in water is not an
exclusive effect of confinement. We further find that, similar to other
glass-forming liquids, the vibrational modes corresponding to the Boson peak
are spatially extended and are related to transverse phonons found in the
parent crystal, here ice Ih.


title: On the strict endoscopic part of modular Siegel threefolds

abstract:
  In this paper we study the non-holomorphic strict endoscopic parts of inner
cohomology spaces of a modular Siegel threefold respect to local systems. First
we show that there is a non-zero subspace of the strict endoscopic part such
that it is constructed by global theta lift of automorphic froms of
$(GL(2)\times GL(2))/G_{m}$. Secondly, we present an explicit analytic
calculation of levels of lifted forms into GSp(4), based on the paramodular
representations theory for $GSp(4; F)$. Finally, we prove the conjecture, by C.
Faber and G. van der Geer, that gives a description of the strict endoscopic
part for Betti cohomology and (real) Hodge structures in the category of mixed
Hodge structures, in which the modular Siegel threefold has level structure
one.


title: Secure Cascade Channel Synthesis

abstract:
  We investigate channel synthesis in a cascade setting where nature provides
an iid sequence $X^n$ at node 1. Node 1 can send a message at rate $R_1$ to
node 2 and node 2 can send a message at rate $R_2$ to node 3. Additionally, all
3 nodes share bits of common randomness at rate $R_0$. We want to generate
sequences $Y^n$ and $Z^n$ along nodes in the cascade such that $(X^n,Y^n,Z^n)$
appears to be appropriately correlated and iid even to an eavesdropper who is
cognizant of the messages being sent. We characterize the optimal tradeoff
between the amount of common randomness used and the required rates of
communication. We also solve the problem for arbitrarily long cascades and
provide an inner bound for cascade channel synthesis without an eavesdropper.


title:
Application of some combinatorial arrays in coloring of total graph of a
  commutative ring

abstract:
  Let $R$ be a commutative ring with unity and $Z(R)$ and ${\rm Reg}(R)$ be the
set of zero-divisors and non-zero zero-divisors of $R$, respectively. We denote
by $T(\Gamma(R))$, the total graph of $R$, a simple graph with the vertex set
$R$ and two distinct vertices $x$ and $y$ are adjacent if and only if $x+y\in
Z(R)$. The induced subgraphs on $Z(R)$ and ${\rm Reg}(R)$ are denoted by
$Z(\Gamma(R))$ and $Reg(\Gamma(R))$, respectively. These graphs were first
introduced by D.F. Anderson and A. Badawi in 2008. In this paper, we prove the
following result: let $R$ be a finite ring and one of the following conditions
hold: (i) The residue field of $R$ of minimum size has even characteristic,
(ii) Every residue field of $R$ has odd characteristic and $\frac{R}{J(R)}$ has
no summand isomorphic to $\mathbb{Z}_3\times \mathbb{Z}_3$, then the chromatic
number and clique number of $T(\Gamma(R))$ are equal to
$\max\{|\mathfrak{m}|\,:\, \mathfrak{m}\in {\rm Max}(R)\}$. The same result
holds for $Z(\Gamma(R))$. Moreover, if the residue field of $R$ of minimum size
has even characteristic or every residue field of $R$ has odd characteristic,
then we determine the chromatic number and clique number of $Reg(\Gamma(R))$ as
well.


title: Direct detection experiments explained with mirror dark matter

abstract:
  Recently, the CDMS/Si experiment has observed a low energy excess of events
in their dark matter search. In light of this new result we update the mirror
dark matter explanation of the direction detection experiments. We find that
the DAMA, CoGeNT, CRESST-II and CDMS/Si data can be simultaneously explained by
halo $\sim Fe'$ interactions provided that $v_{rot} \approx 200$ km/s. Other
parameter space is also possible. Forthcoming experiments, including CDMSlite,
CDEX, COUPP, LUX, C-4,... should be able to further scrutinize mirror dark
matter and closely related hidden sector models in the near future.


title: The least eigenvalue of graphs whose complements are unicyclic

abstract:
  A graph in a certain graph class is called minimizing if the least eigenvalue
of the adjacency matrix of the graph attains the minimum among all graphs in
that class. Bell {\it et al.} have characterized the minimizing graphs in the
class of connected graphs of order $n$ and size $m$, whose complements are
either disconnected or contain a clique of order at least $n/2$. In this paper
we discuss the minimizing graphs of a special class of graphs of order $n$
whose complements are connected and contains exactly one cycle (namely the the
class $\mathscr {U}^{c}_{n}$ of graphs whose complements are unicyclic), and
characterize the unique minimizing graph in $\mathscr {U}^{c}_{n}$ when $n \geq
20$.


title: A nonparametric CUSUM control chart based on the Mann-Whitney statistic

abstract:
  This article aims to consider a new univariate nonparametric cumulative sum
(CUSUM) control chart for small shift of location based on both change-point
model and Mann-Whitney statistic. Some comparisons on the performances of the
proposed chart with other charts as well as the properties of the test
statistic are presented. Simulations indicate that the proposed chart is
sensitive in detection of the small mean shifts of the process by a high
intensive accumulation of sample information when the underlying variable is
completely distribution-free.


title: Multi-command Tactile Brain Computer Interface: A Feasibility Study

abstract:
  The study presented explores the extent to which tactile stimuli delivered to
the ten digits of a BCI-naive subject can serve as a platform for a brain
computer interface (BCI) that could be used in an interactive application such
as robotic vehicle operation. The ten fingertips are used to evoke
somatosensory brain responses, thus defining a tactile brain computer interface
(tBCI). Experimental results on subjects performing online (real-time) tBCI,
using stimuli with a moderately fast inter-stimulus-interval (ISI), provide a
validation of the tBCI prototype, while the feasibility of the concept is
illuminated through information-transfer rates obtained through the case study.


title:
Neutrino hierarchy and fermion spectrum from a single family in six
  dimensions: realistic predictions

abstract:
  In this paper, we move from a "proof of concept" to challenging predictions
in a flavour model emerging from a single fermion family in six dimensions
(6-D) with the two extra dimensions compactified on a sphere. The most striking
predictions (beyond the basic ingredients already demonstrated for a realistic
quark mass pattern) are for the neutrino sector. Not only can 4-D Majorana
masses be generated from 6-D (where no Majorana spinors exist), but Majorana
masses are naturally associated to large mixing. The model favours inverted
hierarchy and a quasi-Dirac partial suppression of neutrinoless double beta
decay.


title:
Fast Estimation of True Bounds on Bermudan Option Prices under
  Jump-diffusion Processes

abstract:
  Fast pricing of American-style options has been a difficult problem since it
was first introduced to financial markets in 1970s, especially when the
underlying stocks' prices follow some jump-diffusion processes. In this paper,
we propose a new algorithm to generate tight upper bounds on the Bermudan
option price without nested simulation, under the jump-diffusion setting. By
exploiting the martingale representation theorem for jump processes on the dual
martingale, we are able to explore the unique structure of the optimal dual
martingale and construct an approximation that preserves the martingale
property. The resulting upper bound estimator avoids the nested Monte Carlo
simulation suffered by the original primal-dual algorithm, therefore
significantly improves the computational efficiency. Theoretical analysis is
provided to guarantee the quality of the martingale approximation. Numerical
experiments are conducted to verify the efficiency of our proposed algorithm.


title: Light Dirac right-handed sneutrino dark matter

abstract:
  We show that mostly right-handed Dirac sneutrino is a viable supersymmetric
light dark matter candidate. While the Dirac sneutrino scattering with nuclei
is dominantly through the $Z$ boson exchange and is stringently constrained by
the invisible decay width of $Z$ boson, it is possible to realize a large
enough cross section with nucleon to account for possible signals observed at
direct dark matter searches such as CDMS II-Si or CoGeNT. Even if the XENON100
limit is taken into account, a small part of signal region for CDMS II-Si
events remains outside the excluded region by XENON100.


title: Dineutron formation and breaking in $^8$He

abstract:
  We discuss the correlation of the spin-singlet two-neutron pair, the
dineutron correlation, in the ground and excited $0^+$ states of $^8$He by
using a method to describe the dineutron correlation in neutron-rich nuclei,
the dineutron condensate wave function. The shell-model configuration and the
dineutron configuration compete with each other in the ground state of $^8$He.
We compare the ground state structure of $^8$He with that of $^6$He and suggest
that the dineutron correlation is weaker in the ground state of $^8$He than
$^6$He. We also suggest the possibility of the dineutron condensation in an
excited $0^+$ state of $^8$He. In addition, we investigate the formation
mechanism of the dineutron condensation in $^8$He by using a newly developed
framework, $\alpha$ and dineutron condensate wave function, and conclude that
the attraction from the core is essential for the formation of the dineutron
condensation.


title:
Horizon-Independent Optimal Prediction with Log-Loss in Exponential
  Families

abstract:
  We study online learning under logarithmic loss with regular parametric
models. Hedayati and Bartlett (2012b) showed that a Bayesian prediction
strategy with Jeffreys prior and sequential normalized maximum likelihood
(SNML) coincide and are optimal if and only if the latter is exchangeable, and
if and only if the optimal strategy can be calculated without knowing the time
horizon in advance. They put forward the question what families have
exchangeable SNML strategies. This paper fully answers this open problem for
one-dimensional exponential families. The exchangeability can happen only for
three classes of natural exponential family distributions, namely the Gaussian,
Gamma, and the Tweedie exponential family of order 3/2. Keywords: SNML
Exchangeability, Exponential Family, Online Learning, Logarithmic Loss,
Bayesian Strategy, Jeffreys Prior, Fisher Information1


title:
Quantum Annealing for Dirichlet Process Mixture Models with Applications
  to Network Clustering

abstract:
  We developed a new quantum annealing (QA) algorithm for Dirichlet process
mixture (DPM) models based on the Chinese restaurant process (CRP). QA is a
parallelized extension of simulated annealing (SA), i.e., it is a parallel
stochastic optimization technique. Existing approaches [Kurihara et al.
UAI2009, Sato et al. UAI2009] and cannot be applied to the CRP because their QA
framework is formulated using a fixed number of mixture components. The
proposed QA algorithm can handle an unfixed number of classes in mixture
models. We applied QA to a DPM model for clustering vertices in a network where
a CRP seating arrangement indicates a network partition. A multi core processor
was used for running QA in experiments, the results of which show that QA is
better than SA, Markov chain Monte Carlo inference, and beam search at finding
a maximum a posteriori estimation of a seating arrangement in the CRP. Since
our QA algorithm is as easy as to implement the SA algorithm, it is suitable
for a wide range of applications.

categories: cond-mat.dis-nn cond-mat.stat-mech quant-ph stat.ML


title:
Nonlinear Elimination of Spin-Exchange Relaxation of High Magnetic
  Moments

abstract:
  Relaxation of the Larmor magnetic moment by spin-exchange collisions has been
shown to diminish for high alkali densities, resulting from the linear part of
the collisional interaction. In contrast, we demonstrate both experimentally
and theoretically the elimination of spin-exchange relaxation of high magnetic
moments (birefringence) in alkali vapor. This elimination originates from the
nonlinear part of the spin-exchange interaction, as a scattering process of the
Larmor magnetic moment. We find counter-intuitively that the threshold magnetic
field is the same as in the Larmor case, despite the fact that the precession
frequency is twice as large.


title:
Cosmological Perturbations in Inflationary Models with Anisotropic
  Space-Time Scaling in Lifshitz Background

abstract:
  Models of inflation in a gravitational background with an anisotropic
space-time scaling are studied. The background is a higher-dimensional Lifshitz
throat with the anisotropy scaling $z\neq 1$. After the dimensional reduction,
the four-dimensional general covariance is explicitly broken to a
three-dimensional spatial diffeomorphism. As a result the cosmological
perturbation theory in this set up with less symmetries have to be formulated.
We present the consistent cosmological perturbation theory for this set up. We
find that the effective four-dimensional gravitational wave perturbations
propagate with a different speed than the higher dimensional gravitational
excitations. Depending on the model parameters, for an observer inside the
throat, the four-dimensional gravitational wave propagation can be
superluminal. We also find that the Bardeen potential and the Newtonian
potential are different. This can have interesting observational consequences
for lensing and CMB fluctuations. Furthermore, we show that at the linearized
level the inflaton field excitations vanish.


title: Competition-induced criticality in a model of meme popularity

abstract:
  Heavy-tailed distributions of meme popularity occur naturally in a model of
meme diffusion on social networks. Competition between multiple memes for the
limited resource of user attention is identified as the mechanism that poises
the system at criticality. The popularity growth of each meme is described by a
critical branching process, and asymptotic analysis predicts power-law
distributions of popularity with very heavy tails (exponent $\alpha<2$, unlike
preferential-attachment models), similar to those seen in empirical data.


title: On the symmetry improved CJT formalism in the $O(4)$ linear sigma model

abstract:
  By using the symmetry improved CJT effective formalism developed by Pilaftsis
and Teresi, the chiral phase transition is reconsidered in the framework of the
$O(4)$ linear sigma model in chiral limit. Our results confirm the restorations
of the second-order phase transition and the Goldstone theorem in the Hartree
approximation. Finally, we explicitly calculate the effective potentials via
the order parameter for various temperatures and address advantages of the
present method in comparison with the $O(N)$ model in large-$N$ approximation.


title: Computing class polynomials for abelian surfaces

abstract:
  We describe a quasi-linear algorithm for computing Igusa class polynomials of
Jacobians of genus 2 curves via complex floating-point approximations of their
roots. After providing an explicit treatment of the computations in quartic CM
fields and their Galois closures, we pursue an approach due to Dupont for
evaluating $\theta$- constants in quasi-linear time using Newton iterations on
the Borchardt mean. We report on experiments with our implementation and
present an example with class number 17608.


title: From dimension free concentration to Poincar\'e inequality

abstract:
  We prove that a probability measure on an abstract metric space satisfies a
non trivial dimension free concentration inequality for the $\ell_2$ metric if
and only if it satisfies the Poincar\'e inequality.


title:
Quasilinear and Hessian type equations with exponential reaction and
  measure data

abstract:
  We prove existence results concerning equations of the type
$-\Delta_pu=P(u)+\mu$ for $p>1$ and $F_k[-u]=P(u)+\mu$ with $1\leq
k<\frac{N}{2}$ in a bounded domain $\Omega$ or the whole $\mathbb{R}^N$, where
$\mu$ is a positive Radon measure and $P(u)\sim e^{au^\beta}$ with $a>0$ and
$\beta\geq 1$. Sufficient conditions for existence are expressed in terms of
the fractional maximal potential of $\mu$. Two-sided estimates on the solutions
are obtained in terms of some precise Wolff potentials of $\mu$. Necessary
conditions are obtained in terms of Orlicz capacities. We also establish
existence results for a general Wolff potential equation under the form $u={\bf
W}_{\alpha,p}^R[P(u)]+f$ in $\mathbb{R}^N$, where $0


title: Variable-length haplotype construction for gene-gene interaction studies

abstract:
  This paper presents a non-parametric classification technique for identifying
a candidate bi-allelic genetic marker set that best describes disease
susceptibility in gene-gene interaction studies. The developed technique
functions by creating a mapping between inferred haplotypes and case/control
status. The technique cycles through all possible marker combination models
generated from the available marker set where the best interaction model is
determined from prediction accuracy and two auxiliary criteria including
low-to-high order haplotype propagation capability and model parsimony. Since
variable-length haplotypes are created during the best model identification,
the developed technique is referred to as a variable-length haplotype
construction for gene-gene interaction (VarHAP) technique. VarHAP has been
benchmarked against a multifactor dimensionality reduction (MDR) program and a
haplotype interaction technique embedded in a FAMHAP program in various
two-locus interaction problems. The results reveal that VarHAP is suitable for
all interaction situations with the presence of weak and strong linkage
disequilibrium among genetic markers.


title:
Scaling and universality in nonlinear optical quantum graphs containing
  star motifs

abstract:
  Quantum graphs have recently emerged as models of nonlinear optical, quantum
confined systems with exquisite topological sensitivity and the potential for
predicting structures with an intrinsic, off-resonance response approaching the
fundamental limit. Loop topologies have modest responses, while bent wires have
larger responses, even when the bent wire and loop geometries are identical.
Topological enhancement of the nonlinear response of quantum graphs is even
greater for star graphs, for which the first hyperpolarizability can exceed
half the fundamental limit. In this paper, we investigate the nonlinear optical
properties of quantum graphs with the star vertex topology, introduce motifs
and develop new methods for computing the spectra of composite graphs. We show
that this class of graphs consistently produces intrinsic optical
nonlinearities near the limits predicted by potential optimization. All graphs
of this type have universal behavior for the scaling of their spectra and
transition moments as the nonlinearities approach the fundamental limit.


title:
Cavity-enhanced real-time monitoring of single charge jumps at the
  microsecond timescale

abstract:
  We use fast coherent reflectivity measurements, in a strongly-coupled quantum
dot-micropillar device, to monitor in real-time single-charge jumps at the
microsecond timescale. Thanks to the strong enhancement of light-matter
interaction inside the cavity, the measurement rate is five orders of magnitude
faster than with previous experiments of direct single-charge sensing with
quantum dots. The monitored transitions, identified at any given time with a
less than 0.2% error probability, correspond to a carrier being captured and
then released by a single material defect. This high-speed technique opens the
way for the real-time monitoring of other rapid single quantum events, such as
the quantum jumps of a single spin.


title:
Generation and characterization of resource state for nonlinear cubic
  phase gate

abstract:
  Unitary non-Gaussian nonlinearity is one of the key components required for
quantum computation and other developing applications of quantum information
processing. Sufficient operation of this kind is still not available, but it
can be approximatively implemented with help of a specifically engineered
resource state constructed from individual photons. We present experimental
realization and thorough analysis of such quantum resource state, and confirm
that the state does indeed possess properties of a state produced by unitary
dynamics driven by cubic nonlinearity.


title: Describing Function-based Approximations of Biomolecular Systems

abstract:
  Mathematical methods provide useful framework for the analysis and design of
complex systems. In newer contexts such as biology, however, there is a need to
both adapt existing methods as well as to develop new ones. Using a combination
of analytical and computational approaches, we adapt and develop the method of
describing functions to represent the input-output responses of biomolecular
signalling systems. We approximate representative systems exhibiting various
saturating and hysteretic dynamics in a way that is better than the standard
linearization. Further, we develop analytical upper bounds for the
computational error estimates. Finally, we use these error estimates to augment
the limit cycle analysis with a simple and quick way to bound the predicted
oscillation amplitude. These results provide system approximations that can add
more insight into the local behaviour of these systems than standard
linearization, compute responses to other periodic inputs, and to analyze limit
cycles.


title:
Centers of near-IR luminescence in Bi-doped SiO2 and GeO2:
  First-principle modeling and experimental data analysis

abstract:
  First-principle study of possible bismuth-related centers in SiO2 and GeO2
hosts is performed and the results are compared with the experimental data. The
following centers are modeled: trivalent and divalent Bi substitutional
centers; BiO interstitial molecule; interstitial ion, Bi^+, and atom, Bi^0;
Bi...Si-Si and Bi...Ge-Ge complexes formed by interstitial Bi atoms and glass
intrinsic defects, Si-Si or Ge-Ge oxygen vacancies; interstitial dimers, Bi0
and Bi_2^-. Experimental data available on bismuth-related IR luminescence in
SiO2:Bi and GeO2:Bi glasses, visible (red) luminescence in SiO2:Bi glass and
the luminescence excitation are analyzed. Comparison of the calculated spectral
properties of the bismuth-related centers with the experimental data shows that
IR luminescence in SiO2:Bi and GeO2:Bi is most likely caused by Bi...Si-Si and
Bi...Ge-Ge complexes and divalent Bi substitutional center is probably
responsible for the red luminescence in SiO2:Bi.


title: Generalized Centroid Estimators in Bioinformatics

abstract:
  In a number of estimation problems in bioinformatics, accuracy measures of
the target problem are usually given, and it is important to design estimators
that are suitable to those accuracy measures. However, there is often a
discrepancy between an employed estimator and a given accuracy measure of the
problem. In this study, we introduce a general class of efficient estimators
for estimation problems on high-dimensional binary spaces, which representmany
fundamental problems in bioinformatics. Theoretical analysis reveals that the
proposed estimators generally fit with commonly-used accuracy measures (e.g.
sensitivity, PPV, MCC and F-score) as well as it can be computed efficiently in
many cases, and cover a wide range of problems in bioinformatics from the
viewpoint of the principle of maximum expected accuracy (MEA). It is also shown
that some important algorithms in bioinformatics can be interpreted in a
unified manner. Not only the concept presented in this paper gives a useful
framework to design MEA-based estimators but also it is highly extendable and
sheds new light on many problems in bioinformatics.


title:
Optical Tamm state and extraordinary light transmission through
  nanoaperture

abstract:
  We investigate the light transmission through a nanoaperture in a metal film
deposited on a planar metamaterial. An effect of an anomalously high light
transmission through the nanoaperture is revealed, which we associate with the
enhancement of the field at the interface of the planar structure
"metamaterial-metal" due to the appearance of an optical Tamm state. In this
structure, we also observe an "optical diode" effect: the light transmission
radically changes as the direction of irradiation of the structure is reversed.
Our numerical results agree well with experimental data.


title:
Short-chain polymer rigidity due to the Debye process of monohydroxy
  alcohols

abstract:
  In addition to the ubiquitous structural relaxation of viscous supercooled
liquids, monohydroxy alcohols and several other hydrogen-bonded systems display
a strong single-exponential electrical low-frequency absorption. So far, this
so-called Debye process could be observed only using dielectric techniques.
Exploiting a combination of broad-band and high-resolution rheology experiments
for three isomeric octanols, unambiguous mechanical evidence for the Debye
process is found. Its spectral signature is similar to the viscoelastic
fingerprint of small-chain polymers, enabling us to estimate the effective
molecular weight for the supramolecular structure formed by the studied
monohydroxy alcohols. This finding opens the venue for the application of
further non-dielectric techniques directed at unraveling the microscopic nature
of the Debye process and for an understanding of this phenomenon in terms of
polymer concepts.


title: Solution to an isotopism question concerning rank 2 semifields

abstract:
  In [U. Dempwolff: More Translation Planes and Semifields from
Dembowski-Ostrom Polynomials, Designs, Codes, Cryptogr. \textbf{68} (1-3)
(2013), 81-103], the author gives a construction of three classes of rank two
semifields of order $q^{2n}$, with $q$ and $n$ odd, using Dembowski-Ostrom
polynomials. The question whether these semifields are new, i.e. not isotopic
to previous constructions, is left as an open problem. In this paper we solve
this problem for $n>3$, in particular we prove that two of these classes,
labeled $D_{A}$ and $D_{AB}$, are new for $n>3$, whereas presemifields in
family $D_{B}$ are isotopic to Generalized Twisted Fields for each $n\geq 3$.


title: Computing Cox rings

abstract:
  We consider modifications, for example blow ups, of Mori dream spaces and
provide algorithms for investigating the effect on the Cox ring, e.g. testing
finite generation or computing an explicit presentation in terms of generators
and relations. As a first application, we compute the Cox rings of all
Gorenstein log del Pezzo surfaces of Picard number one. Moreover, we show
computationally that all smooth rational surfaces of Picard number at most six
are Mori dream surfaces and we provide explicit presentations of the Cox ring
for those not admitting a torus action. Finally, we provide the Cox rings of
projective spaces blown up at a certain special point configurations.


title: Lovelock Gravity with Spontaneous Dimensional Breaking

abstract:
  We consider D-dimensional Lovelock gravity with only one term of higher-order
Lovelock Lagrangian densities, and show that a product of Minkowski space-time
and n-spheres is its vacuum solution. The most interesting feature of our model
is that the spontaneous compactification of the extra dimensions results in
reproduction of the Einstein gravity with no cosmological constant.


title: Ensembles of Classifiers based on Dimensionality Reduction

abstract:
  We present a novel approach for the construction of ensemble classifiers
based on dimensionality reduction. Dimensionality reduction methods represent
datasets using a small number of attributes while preserving the information
conveyed by the original dataset. The ensemble members are trained based on
dimension-reduced versions of the training set. These versions are obtained by
applying dimensionality reduction to the original training set using different
values of the input parameters. This construction meets both the diversity and
accuracy criteria which are required to construct an ensemble classifier where
the former criterion is obtained by the various input parameter values and the
latter is achieved due to the decorrelation and noise reduction properties of
dimensionality reduction. In order to classify a test sample, it is first
embedded into the dimension reduced space of each individual classifier by
using an out-of-sample extension algorithm. Each classifier is then applied to
the embedded sample and the classification is obtained via a voting scheme. We
present three variations of the proposed approach based on the Random
Projections, the Diffusion Maps and the Random Subspaces dimensionality
reduction algorithms. We also present a multi-strategy ensemble which combines
AdaBoost and Diffusion Maps. A comparison is made with the Bagging, AdaBoost,
Rotation Forest ensemble classifiers and also with the base classifier which
does not incorporate dimensionality reduction. Our experiments used seventeen
benchmark datasets from the UCI repository. The results obtained by the
proposed algorithms were superior in many cases to other algorithms.