title: Optical Dichroism by Nonlinear Excitations in Graphene Nanoribbons

abstract:
  The honeycomb carbon structure of graphene and nanotubes has a dynamics which
can give rise to a spectrum. This can be excited via the interaction with an
external electromagnetic field. In this work, non-linear waves on graphene and
nanotubes associated with the carbon structure are investigated using a gauge
model. Typical energies are estimated and there scaling with the nanoribbon
width investigated. Furthermore, the soliton-photon interaction depends on the
incident photon polarization. In particular, we find that the nanoribbon is
transparent when the polarization is along the largest length. Relying on the
scaling with the width, we suggest a way to experimentally identify the soliton
waves in nanoribbons.


title:
Fluctuations of charge separation perpendicular to the event plane and
  local parity violation in sqrt(sNN)=200 GeV Au+Au collisions at RHIC

abstract:
  Previous experimental results based on data (15 million events) collected by
the STAR detector at RHIC suggest event-by-event charge separation fluctuations
perpendicular to the event plane in non-central heavy-ion collisions. Here we
present the correlator previously used split into its two component parts to
reveal correlations parallel and perpendicular to the event plane. The results
are from a high statistics 200 GeV Au+Au collisions data set (57 million
events) collected by the STAR experiment. We explicitly count units of charge
separation from which we find clear evidence for more charge separation
fluctuations perpendicular than parallel to the event plane. We also employ a
modified correlator to study the possible P-even background in same and
opposite charge correlations, and find that the P-even background may largely
be explained by momentum conservation and collective motion.


title: Quantum anholonomy with topology change

abstract:
  We study a family of closed quantum graphs described by one singular vertex
of order n=4. By suitable choice of the parameters specifying the singular
vertex, we can construct a closed sequence of paths in the parameter space that
physically corresponds to the smooth interpolation of different topologies - a
ring, separate two lines, separate two rings, two rings with a contact point.
We find that the spectrum of a quantum particle on this family of graphs shows
the quantum anholonomy.


title:
Blazar Anti-Sequence of Spectral Variation within individual Blazars:
  Cases for Mrk 501 and 3C 279

abstract:
  The jet properties of Mrk 501 and 3C 279 are derived by fitting the broadband
spectral energy distributions with the lepton models. The derived gamma_b (the
break Lorenz factor of the electron distribution) are 10^4-10^6 for Mrk 501 and
200~600 for 3C 279 and the magnetic field strength (B) of Mrk 501 is usually
one order of magnitude lower than that of 3C 279, but their Doppler factors
(delta) are comparable. A spectral variation feature that the peak luminosity
is correlated with the peak frequency, which is opposite to the blazar
sequence, is observed in the two sources. We find that (1) the peak
luminosities of the two bumps in SEDs for Mrk 501 depend on gamma_b in both the
observer and co-moving frames, but they are not correlated with B and delta;
(2)the luminosity variation of 3C 279 is dominated by the external Compton (EC)
peak and its peak luminosity is correlated with gamma_b and delta, but
anti-correlated with B. These results suggest that gamma_b may govern the
spectral variation of Mrk 501 and delta and B would be responsible for the
spectral variation of 3C 279. The narrow distribution of gamma_b and the
correlation of gamma_b and B in 3C 279 would be due to the cooling by the EC
process and the strong magnetic field. Based on our brief discussion, we
propose that this spectral variation feature may be originated from the
instability of the corona but not from the variation of the accretion rate as
that for the blazar sequence.


title: Non-Commutative Gebauer-Moeller Criteria

abstract:
  For an efficient implementation of Buchberger's Algorithm, it is essential to
avoid the treatment of as many unnecessary critical pairs or obstructions as
possible. In the case of the commutative polynomial ring, this is achieved by
the Gebauer-Moeller criteria. Here we present an adaptation of the
Gebauer-Moeller criteria for non-commutative polynomial rings, i.e. for free
associative algebras over fields. The essential idea is to detect unnecessary
obstructions using other obstructions with or without overlap. Experiments show
that the new criteria are able to detect almost all unnecessary obstructions
during the execution of Buchberger's procedure.


title:
Localization and shock waves in curved manifolds for the
  Gross-Pitaevskii equation

abstract:
  We investigate the dynamics of a Bose-Einstein condensate in a progressively
bended three dimensional cigar shaped potential. The interplay between geometry
and nonlinearity is considered. At high curvature, topological localization
occurs and becomes frustrated by the generation of curved dispersive
shock-waves when the strength of nonlinearity is increased. The analysis is
supported by four-dimensional parallel simulations.


title:
On-chip time resolved detection of quantum dot emission using integrated
  superconducting single photon detectors

abstract:
  We report the routing of quantum light emitted by self-assembled InGaAs
quantum dots (QDs) into the optical modes of a GaAs ridge waveguide and its
efficient detection on-chip via evanescent coupling to NbN superconducting
nanowire single photon detectors (SNSPDs). Individual QD light sources embedded
within such integrated nano-photonic circuits are highly attractive for the
realization of quantum photonic circuits for many applications in photonic
information science. Here, we demonstrate that the waveguide coupled SNSPDs
primarily detect QD luminescence with scattered photons from the excitation
laser being negligible by comparison. The SNSPD detection efficiency from the
evanescently coupled waveguide modes is shown to be two orders of magnitude
higher when compared with operation under normal incidence illumination.
Furthermore, in-situ time resolved measurements show an average exciton
lifetime of 0.93 \pm 0.03 ns when recorded with the integrated detector with an
ultrafast timing jitter of only 72 \pm 2 ps showing the great potential of this
highly integrated quantum optics system.


title: The quantum Hall hierarchy in spherical geometry

abstract:
  Representative wave functions, which encode the topological properties of the
spin polarized fractional quantum Hall states in the lowest Landau level, can
be expressed in terms of correlation functions in conformal field theories.
Until now, the constructions have been restricted to flat geometries, but in
this paper we generalize to the simplest curved geometry, namely that of a
sphere. Except for being of interest for numerical studies, that usually are
performed on a sphere, the response of the FQH liquids to curvature can be used
to detect a topological quantity, the shift, which is the average orbital spin
of the constituent electrons. We give explicit expressions for representative
wave functions on the sphere, for the full Abelian FQH hierarchy, and calculate
the corresponding shifts. These microscopic results, based on wave functions,
agree with the predictions from the effective Chern-Simons field theory. The
methods we develop can also be applied to the planar case. It gives simpler
expressions for states with both quasiparticle and quasihole condensates, and
allows us to give closed form expressions for a general state in the hierarchy,
rather than finding the wave function on a case by case basis.


title:
Variable density preserving topology grids and the digital models for
  the plane

abstract:
  We define LCL decompositions of the plane and investigate the advantages of
using such decompositions in the context of digital topology. We show that
discretization schemes based on such decompositions associate, to each LCL
tiling of the plane, the digital model preserving the local topological
structure of the object. We prove that for any LCL tiling of the plane, the
digital model is necessarily a digital 2-manifold. We show that elements of an
LCL tiling can be of an arbitrary shape and size. This feature generates a
variable density grid with a required resolution in any region of interest,
which is extremely important in medicine. Finally, we describe a simple
algorithm, which allows transforming regions of interest produced by the image
acquisition process into digital spaces with topological features of the
regions.


title:
Synchronization, quantum correlations and entanglement in oscillator
  networks

abstract:
  Synchronization is one of the paradigmatic phenomena in the study of complex
systems. It has been explored theoretically and experimentally mostly to
understand natural phenomena, but also in view of technological applications.
Although several mechanisms and conditions for synchronous behavior in
spatially extended systems and networks have been identified, the emergence of
this phenomenon has been largely unexplored in quantum systems until very
recently. Here we discuss synchronization in quantum networks of different
harmonic oscillators relaxing towards a stationary state, being essential the
form of dissipation. By local tuning of one of the oscillators, we establish
the conditions for synchronous dynamics, in the whole network or in a motif.
Beyond the classical regime we show that synchronization between (even
unlinked) nodes witnesses the presence of quantum correlations and
entanglement. Furthermore, synchronization and entanglement can be induced
between two different oscillators if properly linked to a random network.


title: Indicated coloring of matroids

abstract:
  A coloring of a matroid is proper if elements of the same color form an
independent set. For a loopless matroid M, its chromatic number \chi(M) is the
minimum number of colors that suffices to color properly the ground set E of M.
In this note we study a game-theoretic variant of this parameter proposed by
Grytczuk. Suppose that in each round of the game Alice indicates an uncolored
yet element e of E, then Bob colors it using a color from a fixed set of colors
C. The rule Bob has to obey is that it is a proper coloring. The game ends if
the whole matroid has been colored or if Bob can not color e using any color of
C. Alice wins in the first case, while Bob in the second. The minimum size of
the set of colors C for which Alice has a winning strategy is called the
indicated chromatic number of M, denoted by \chi_i(M). We prove that
\chi_i(M)=\chi(M).


title: Almost commensurability of 3-dimensional Anosov flows

abstract:
  Two flows are topologically almost commensurable if, up to removing finitely
many periodic orbits and taking finite coverings, they are topologically
equivalent. We prove that all suspensions of automorphisms of the 2-dimensional
torus and all geodesic flows on unit tangent bundles to hyperbolic 2-orbifolds
are pairwise almost commensurable.


title: Affine surfaces with a huge group of automorphisms

abstract:
  We describe a family of rational affine surfaces S with huge groups of
automorphisms in the following sense: the normal subgroup of Aut(S) generated
by all its algebraic subgroups is not generated by any countable family of such
subgroups, and the quotient of Aut(S) by this subgroup contains a free group
over an uncountable set of generators.


title: Multi-solitary waves for the nonlinear Klein-Gordon equation

abstract:
  We consider the nonlinear Klein-Gordon equation in $\R^d$. We call
multi-solitary waves a solution behaving at large time as a sum of boosted
standing waves. Our main result is the existence of such multi-solitary waves,
provided the composing boosted standing waves are stable. It is obtained by
solving the equation backward in time around a sequence of approximate
multi-solitary waves and showing convergence to a solution with the desired
property. The main ingredients of the proof are finite speed of propagation,
variational characterizations of the profiles, modulation theory and energy
estimates.


title: Universal properties of infrared oscillator basis extrapolations

abstract:
  Recent work has shown that a finite harmonic oscillator basis in nuclear
many-body calculations effectively imposes a hard-wall boundary condition in
coordinate space, motivating infrared extrapolation formulas for the energy and
other observables. Here we further refine these formulas by studying two-body
models and the deuteron. We accurately determine the box size as a function of
the model space parameters, and compute scattering phase shifts in the harmonic
oscillator basis. We show that the energy shift can be well approximated in
terms of the asymptotic normalization coefficient and the bound-state momentum,
discuss higher-order corrections for weakly bound systems, and illustrate this
universal property using unitarily equivalent calculations of the deuteron.


title:
Common fixed points for three or four mappings via common fixed point
  for two mappings

abstract:
  In this paper, we shall show that some coincidence point and common fixed
point results for three or four mappings could easily be obtained from the
corresponding fixed point results for two mappings.


title:
Ab initio study of edge effect on relative motion of walls in carbon
  nanotubes

abstract:
  Interwall interaction energies of double-walled nanotubes (DWNTs) with long
inner and short outer walls are calculated as functions of coordinates
describing relative rotation and displacement of the walls using van der Waals
corrected density functional theory. The magnitude of corrugation and the shape
of the potential energy relief are found to be very sensitive to changes of the
shorter wall length at subnanometer scale and atomic structure of the edges if
at least one of the walls is chiral. Threshold forces required to start
relative motion of the short walls and temperatures at which the transition
between diffusive and free motion of the short walls takes place are estimated.
The edges are also shown to provide a considerable contribution to the barrier
to relative rotation of commensurate nonchiral walls. For such walls,
temperatures of orientational melting, i.e. the crossover from rotational
diffusion to free relative rotation, are estimated. The possibility to produce
nanotube-based bolt/nut pairs and nanobearings is discussed.


title:
Bimodality in the firm size distributions: a kinetic exchange model
  approach

abstract:
  Firm growth process in the developing economies is known to produce
divergence in their growth path giving rise to bimodality in the size
distribution. Similar bimodality has been observed in wealth distribution as
well. Here, we introduce a modified kinetic exchange model which can reproduce
such features. In particular, we will show numerically that a nonlinear
retention rate (or savings propensity) causes this bimodality. This model can
accommodate binary trading as well as the whole system-side trading thus making
it more suitable to explain the non-standard features of wealth distribution as
well as firm size distribution.


title: Doubly-periodic instability pattern in a smectic A liquid crystal

abstract:
  We report the observation of a doubly-periodic surface defect-pattern in the
liquid crystal 8CB, formed during the nematic--smectic A phase transition. The
pattern results from the antagonistic alignment of the 8CB molecules, which is
homeotropic at the surface and planar in the bulk of the sample cell. Within
the continuum Landau-deGennes theory of smectic liquid crystals, we find that
the long period (~10 \mu m) of the pattern is given by the balance between the
surface anchoring and the elastic energy of curvature wall defects. The short
period (~1 \mu m) we attribute to a saddle-splay distortion, leading to a
non-zero Gaussian curvature and causing the curvature walls to break up.


title:
Breathfinding: A Wireless Network that Monitors and Locates Breathing in
  a Home

abstract:
  This paper explores using RSS measurements on many links in a wireless
network to estimate the breathing rate of a person, and the location where the
breathing is occurring, in a home, while the person is sitting, laying down,
standing, or sleeping. The main challenge in breathing rate estimation is that
"motion interference", i.e., movements other than a person's breathing,
generally cause larger changes in RSS than inhalation and exhalation. We
develop a method to estimate breathing rate despite motion interference, and
demonstrate its performance during multiple short (3-7 minute) tests and during
a longer 66 minute test. Further, for the same experiments, we show the
location of the breathing person can be estimated, to within about 2 m average
error in a 56 square meter apartment. Being able to locate a breathing person
who is not otherwise moving, without calibration, is important for applications
in search and rescue, health care, and security.


title:
Investigation of the Earth Ionosphere using the Radio Emission of
  Pulsars

abstract:
  The investigation of the Earth ionosphere both in a quiet and a disturbed
states is still desirable. Despite recent progress in its modeling and in
estimating the electron concentration along the line of sight by GPS signals,
the impact of the disturbed ionosphere and magnetic field on the wave
propagation still remains not sufficiently understood. This is due to lack of
information on the polarization of GPS signals, and due to poorly conditioned
models of the ionosphere at high altitudes and strong perturbations. In this
article we consider a possibility of using the data of pulsar radio emission,
along with the traditional GPS system data, for the vertical and oblique
sounding of the ionosphere. This approach also allows to monitor parameters of
the propagation medium, such as the dispersion measure and the rotation measure
using changes of the polarization between pulses. By using a selected pulsar
constellation it is possible to increase the number of directions in which
parameters of the ionosphere and the magnetic field can be estimated.


title:
Roots of characteristic polynomials and intersection points of line
  arrangements

abstract:
  We study a relation between roots of characteristic polynomials and
intersection points of line arrangements. Using these results, we obtain a lot
of applications for line arrangements. Namely, we give (i) a generalized
addition theorem for line arrangements, (ii) a generalization of
Faenzi-Vall\`{e}s' theorem over a field of arbitrary characteristic, (iii) a
partial result on the conjecture of Terao of line arrangements, and (iv) a new
sufficient condition for freeness over finite fields. Also, a higher
dimensional version of main results is considered.


title:
Dynamical decoupling with tailored waveplates for long distance
  communication using polarization qubits

abstract:
  We address the issue of dephasing effects in flying polarization qubits
propagating through optical fiber by using the method of dynamical decoupling.
The control pulses are implemented with half waveplates suitably placed along
the realistic lengths of the single mode optical fiber. The effects of the
finite widths of the waveplates on the polarization rotation are modeled using
tailored refractive index profiles inside the waveplates. We show that
dynamical decoupling is effective in preserving the input qubit state with the
fidelity close to one when the polarization qubit is subject to the random
birefringent noise in the fiber, as well the rotational imperfections
(flip-angle errors) due to the finite width of the waveplates.


title: Tunable electromagnetic environment for superconducting quantum bits

abstract:
  We introduce a setup which realises a tunable engineered environment for
experiments in circuit quantum electrodynamics. We illustrate this concept with
the specific example of a quantum bit, qubit, in a high-quality-factor cavity
which is capacitively coupled to another cavity including a resistor. The
temperature of the resistor, which acts as the dissipative environment, can be
controlled in a well defined manner in order to provide a hot or cold
environment for the qubit, as desired. Furthermore, introducing superconducting
quantum interference devices (SQUIDs) into the cavity containing the resistor,
provides control of the coupling strength between this artificial environment
and the qubit. We demonstrate that our scheme allows us to couple strongly to
the environment enabling rapid initialization of the system, and by subsequent
tuning of the magnetic flux of the SQUIDs we may greatly reduce the
resistor-qubit coupling, allowing the qubit to evolve unhindered.


title:
The consequences of large \theta_13 for the turbulence signatures in
  supernova neutrinos

abstract:
  The set of transition probabilities for a single neutrino emitted from a
point source after passage through a turbulent supernova density profile have
been found to be random variates drawn from parent distributions whose
properties depend upon the stage of the explosion, the neutrino energy and
mixing parameters, the observed channel, and the properties of the turbulence
such as the amplitude C*. In this paper we examine the consequences of the
recently measured mixing angle \theta_13 upon the neutrino flavor
transformation in supernova when passing through turbulence. We find the
measurements of a relatively large value of \theta_13 means the neutrinos are
relatively immune to small, C* < 1%, amplitude turbulence but as C* increases
the turbulence effects grow rapidly and spread to all mixing channels. For C* >
10% the turbulence effects in the high (H) density resonance mixing channels
are independent of \theta_13 but non-resonant mixing channels are more
sensitive to turbulence when \theta_13 is large.


title: Quickest Search Over Multiple Sequences with Mixed Observations

abstract:
  The problem of sequentially finding an independent and identically
distributed (i.i.d.) sequence that is drawn from a probability distribution
$F_1$ by searching over multiple sequences, some of which are drawn from $F_1$
and the others of which are drawn from a different distribution $F_0$, is
considered. The sensor is allowed to take one observation at a time. It has
been shown in a recent work that if each observation comes from one sequence,
Cumulative Sum (CUSUM) test is optimal. In this paper, we propose a new
approach in which each observation can be a linear combination of samples from
multiple sequences. The test has two stages. In the first stage, namely
scanning stage, one takes a linear combination of a pair of sequences with the
hope of scanning through sequences that are unlikely to be generated from $F_1$
and quickly identifying a pair of sequences such that at least one of them is
highly likely to be generated by $F_1$. In the second stage, namely refinement
stage, one examines the pair identified from the first stage more closely and
picks one sequence to be the final sequence. The problem under this setup
belongs to a class of multiple stopping time problems. In particular, it is an
ordered two concatenated Markov stopping time problem. We obtain the optimal
solution using the tools from the multiple stopping time theory. Numerical
simulation results show that this search strategy can significantly reduce the
searching time, especially when $F_{1}$ is rare.


title: Nemesis encounters of nearby Hipparcos stars

abstract:
  Very close encounters of stars might lead to significant perturbations of
their Oort-type clouds, planetesimal belts and planetary systems. We have
calculated encounter parameters of Hipparcos stars using HIP2, Pulkovo and
CRVAD2 catalogs of radial velocities. It turns out that some stars have
encounters within 0.1 pc from each other and might be on an essential collision
course up to few thousands AU. We present here examples with accurate
astrometric data and stable with respect to errors of radial velocities within
$\pm 0.3$ km/s. They include $\beta$ vs. $\gamma$ Virginis, 61 Cygni vs.
$\chi^1$ Orionis as well as close encounters involving $\eta$ Bo\"otis, AB
Doradus, 61 Urs{\ae} Majoris and others.


title: Rumor Spreading in Random Evolving Graphs

abstract:
  Randomized gossip is one of the most popular way of disseminating information
in large scale networks. This method is appreciated for its simplicity,
robustness, and efficiency. In the "push" protocol, every informed node
selects, at every time step (a.k.a. round), one of its neighboring node
uniformly at random and forwards the information to this node. This protocol is
known to complete information spreading in $O(\log n)$ time steps with high
probability (w.h.p.) in several families of $n$-node "static" networks. The
Push protocol has also been empirically shown to perform well in practice, and,
specifically, to be robust against dynamic topological changes.
  In this paper, we aim at analyzing the Push protocol in "dynamic" networks.
We consider the "edge-Markovian" evolving graph model which captures natural
temporal dependencies between the structure of the network at time $t$, and the
one at time $t+1$. Precisely, a non-edge appears with probability $p$, while an
existing edge dies with probability $q$. In order to fit with real-world
traces, we mostly concentrate our study on the case where $p=\Omega(1/n)$ and
$q$ is constant. We prove that, in this realistic scenario, the Push protocol
does perform well, completing information spreading in $O(\log n)$ time steps
w.h.p. Note that this performance holds even when the network is, w.h.p.,
disconnected at every time step (e.g., when $p << (\log n) / n$). Our result
provides the first formal argument demonstrating the robustness of the Push
protocol against network changes. We also address other ranges of parameters
$p$ and $q$ (e.g., $p+q=1$ with arbitrary $p$ and $q$, and $p=1/n$ with
arbitrary $q$). Although they do not precisely fit with the measures performed
on real-world traces, they can be of independent interest for other settings.
The results in these cases confirm the positive impact of dynamism.


title:
The boundaries of dipole graphs and the complete bipartite graphs
  K_{2,n}

abstract:
  We study the Seifert surfaces of a link by relating the embeddings of graphs
by using induced graphs. As applications, we prove that every link $L$ is the
boundary of an oriented surface which is obtained from a graph embedding of a
complete bipartite graph $K_{2,n}$, where all voltage assignments on the edges
of $K_{2,n}$ are 0. We also provide an algorithm to construct such a graph
diagram of a given link and demonstrate the algorithm by dealing with the links
$4_1^2$ and $5_2$.


title: Cooperative Boolean systems with generically long attractors II

abstract:
  We prove that cooperativity in Boolean networks precludes a strong notion of
sensitive dependence on initial conditions. Weaker notions of sensitive
dependence are shown to be consistent with cooperativity, but if each
regulatory functions is binary AND or binary OR, in N-dimensional networks they
impose an upper bound of approximately sqrt(3)^N on the lengths of attractors
that can be reached from a fraction p approaching 1 of initial conditions. The
upper bound is shown to be sharp.


title: Quantum Entanglement in Concept Combinations

abstract:
  Research in the application of quantum structures to cognitive science
confirms that these structures quite systematically appear in the dynamics of
concepts and their combinations and quantum-based models faithfully represent
experimental data of situations where classical approaches are problematical.
In this paper, we analyze the data we collected in an experiment on a specific
conceptual combination, showing that Bell's inequalities are violated in the
experiment. We present a new refined entanglement scheme to model these data
within standard quantum theory rules, where 'entangled measurements and
entangled evolutions' occur, in addition to the expected 'entangled states',
and present a full quantum representation in complex Hilbert space of the data.
This stronger form of entanglement in measurements and evolutions might have
relevant applications in the foundations of quantum theory, as well as in the
interpretation of nonlocality tests. It could indeed explain some
non-negligible 'anomalies' identified in EPR-Bell experiments.


title:
Multiscale model for the effects of adaptive immunity suppression on the
  viral therapy of cancer

abstract:
  Oncolytic virotherapy - the use of viruses that specifically kill tumor cells
- is an innovative and highly promising route for treating cancer. However, its
therapeutic outcomes are mainly impaired by the host immune response to the
viral infection. In the present work, we propose a multiscale mathematical
model to study how the immune response interferes with the viral oncolytic
activity. The model assumes that cytotoxic T cells can induce apoptosis in
infected cancer cells and that free viruses can be inactivated by neutralizing
antibodies or cleared at a constant rate by the innate immune response. Our
simulations suggest that reprogramming the immune microenvironment in tumors
could substantially enhance the oncolytic virotherapy in immune-competent
hosts. Viable routes to such reprogramming are either in situ virus-mediated
impairing of CD$8^+$ T cells motility or blockade of B and T lymphocytes
recruitment. Our theoretical results can shed light on the design of viral
vectors or new protocols with neat potential impacts on the clinical practice.


title: Loop Quantum Cosmology

abstract:
  This Chapter provides an up to date, pedagogical review of some of the most
relevant advances in loop quantum cosmology. We review the quantization of
homogeneous cosmological models, their singularity resolution and the
formulation of effective equations that incorporate the main quantum
corrections to the dynamics. We also summarize the theory of quantized metric
perturbations propagating in those quantum backgrounds. Finally, we describe
how this framework can be applied to obtain a self-consistent extension of the
inflationary scenario to incorporate quantum aspects of gravity, and to explore
possible phenomenological consequences.


title: Non-Bayesian Quickest Detection with Stochastic Sample Right Constraints

abstract:
  In this paper, we study the design and analysis of optimal detection scheme
for sensors that are deployed to monitor the change in the environment and are
powered by the energy harvested from the environment. In this type of
applications, detection delay is of paramount importance. We model this problem
as quickest change detection problem with a stochastic energy constraint. In
particular, a wireless sensor powered by renewable energy takes observations
from a random sequence, whose distribution will change at a certain unknown
time. Such a change implies events of interest. The energy in the sensor is
consumed by taking observations and is replenished randomly. The sensor cannot
take observations if there is no energy left in the battery. Our goal is to
design a power allocation scheme and a detection strategy to minimize the worst
case detection delay, which is the difference between the time when an alarm is
raised and the time when the change occurs. Two types of average run length
(ARL) constraint, namely an algorithm level ARL constraint and an system level
ARL constraint, are considered. We propose a low complexity scheme in which the
energy allocation rule is to spend energy to take observations as long as the
battery is not empty and the detection scheme is the Cumulative Sum test. We
show that this scheme is optimal for the formulation with the algorithm level
ARL constraint and is asymptotically optimal for the formulations with the
system level ARL constraint.


title: On the semi-threading of knot diagrams with minimal overpasses

abstract:
  Given a knot diagram $D$, we construct a semi-threading circle for it which
can be an axis of $D$ as a closed braid depending on knot diagrams. In
particular, we consider semi-threading circles for minimal diagrams of a knot
with respect to overpasses which give us some information related to the braid
index. By this notion, we show that, for every nontrivial knot $K$, the braid
index $b(K)$ of $K$ is not less than the minimum number $l(K)$ of overpasses of
diagrams. Moreover, they are the same for a torus knot.


title: Chiral Hadronic Mean Field Model including Quark Degrees of Freedom

abstract:
  In an approach inspired by Polyakov loop extended NJL models, we present a
nonlinear hadronic SU(3) sigma-omega mean field model augmented by quark
degrees of freedom. By introducing the effective Polyakov loop related scalar
field \Phi and an associated effective potential, the model includes all known
hadronic degrees of freedom at low temperatures and densities as well as a
quark phase at high temperatures and densities. Hadrons in the model exhibit a
finite volume in order to suppress baryons at high T and \mu. This ensures that
the right asymptotic degrees of freedom are attained for the description of
strongly interacting matter and allows to study the QCD phase diagram in a wide
range of temperatures and chemical potentials. Therefore, with this model it is
possible to study the phase transition of chiral restoration and deconfinement.
In this paper, the impact of quarks on the resulting phase diagram is shown.
The results from the chiral model are compared to recent data from lattice QCD.


title:
Storing magnetic information in IrMn/MgO/Ta tunnel junctions via
  field-cooling

abstract:
  Tunneling junctions containing no ferromagnetic elements have been fabricated
and we show that distinct resistance states can be set by field cooling the
devices from above the N\'eel along different orientations. Variations of the
resistance up to 10% are found upon field cooling in applied fields of 2T,
in-plane or out of plane. Below TN, we found that the metastable states are
insensitive to magnetic fields thus constituting a memory element robust
against external magnetic fields. Our work provides the demonstration of an
electrically readable magnetic memory device, which contains no ferromagnetic
elements and stores the information in an antiferromagnetic active layer.


title: Thermal noise for quantum state inference

abstract:
  In this work we describe a simple and efficient scheme for inference of
photon number distribution by adding variable thermal noise to the signal. The
inference remains feasible even if the scheme parameters are subject to random
dynamical change.


title:
Intersections of multiplicative subgroups and Heilbronn's exponential
  sum

abstract:
  The paper is devoted to some applications of Stepanov method. In the first
part of the paper we obtain the estimate of the cardinality of the set, which
is obtained as an intersection of additive shifts of some different subgroups
of F^*_p. In the second part we prove a new upper bound for Heilbronn's
exponential sum and obtain a series of applications of our result to
distribution of Fermat quotients. Also we study additive decompositions of
multiplicative subgroups.


title: On the Ramsey number of the triangle and the cube

abstract:
  The Ramsey number r(K_3,Q_n) is the smallest integer N such that every
red-blue colouring of the edges of the complete graph K_N contains either a red
n-dimensional hypercube, or a blue triangle. Almost thirty years ago, Burr and
Erd\H{o}s conjectured that r(K_3,Q_n) = 2^{n+1} - 1 for every n \in \N, but the
first non-trivial upper bound was obtained only recently, by Conlon, Fox, Lee
and Sudakov, who proved that r(K_3,Q_n) \le 7000 \cdot 2^n. Here we show that
r(K_3,Q_n) = (1 + o(1)) 2^{n+1} as n \to \infty.


title: Noncompact harmonic manifolds

abstract:
  The Lichnerowicz conjecture asserts that all harmonic manifolds are either
flat or locally symmetric spaces of rank 1. This conjecture has been proved by
Z.I. Szabo for harmonic manifolds with compact universal cover. E. Damek and F.
Ricci provided examples showing that in the noncompact case the conjecture is
wrong. However, such manifolds do not admit a compact quotient. The
classification of all noncompact harmonic spaces is still a very difficult open
problem.
  In this paper we provide a survey on recent results on noncompact simply
connected harmonic manifolds, and we also prove many new results, both for
general noncompact harmonic manifolds and for noncompact harmonic manifolds
with purely exponential volume growth.


title: Transporting non-Gaussianity from sub to super-horizon scales

abstract:
  We extend the `moment transport method' for calculating the statistics of
inflationary perturbations to the quantum phase of evolution on sub-horizon
scales. The quantum transport equations form a set of coupled ordinary
differential equations for the evolution of quantum correlation functions
during inflation, which are valid on sub- and super-horizon scales, and reduce
to the known classical transport equations after horizon crossing. The
classical and quantum equations follow directly from the field equations of
cosmological perturbation theory. In this paper, we focus on how the evolution
equations arise, and explore how transport methods relate to other approaches,
and in particular how formal integral solutions to the transport equations
connect to those of the In-In formalism.


title:
Going beyond the linear approximation in describing electron- phonon
  coupling: relevance for the Holstein model

abstract:
  Using the momentum average approximation we study the importance of adding
higher-than-linear terms in the electron-phonon coupling on the properties of
single polarons described by a generalized Holstein model. For medium and
strong linear coupling, even small quadratic electron-phonon coupling terms are
found to lead to very significant quantitative changes in the properties of the
polaron, which cannot be captured by a linear Holstein Hamiltonian with
renormalized parameters. We argue that the bi-polaron phase diagram is equally
sensitive to addition of quadratic coupling terms if the linear coupling is
large. These results suggest that the linear approximation is likely to be
inappropriate to model systems with strong electron-phonon coupling, at least
for low carrier concentrations.


title: Infinite Self-Shuffling Words

abstract:
  In this paper we introduce and study a new property of infinite words: An
infinite word $x\in A^\mathbb{N}$, with values in a finite set $A$, is said to
be $k$-self-shuffling $(k\geq 2)$ if $x$ admits factorizations:
$x=\prod_{i=0}^\infty U_i^{(1)}\cdots U_i^{(k)}=\prod_{i=0}^\infty
U_i^{(1)}=\cdots =\prod_{i=0}^\infty U_i^{(k)}$. In other words, there exists a
shuffle of $k$-copies of $x$ which produces $x$. We are particularly interested
in the case $k=2$, in which case we say $x$ is self-shuffling. This property of
infinite words is shown to be an intrinsic property of the word and not of its
language (set of factors). For instance, every aperiodic word contains a non
self-shuffling word in its shift orbit closure. While the property of being
self-shuffling is a relatively strong condition, many important words arising
in the area of symbolic dynamics are verified to be self-shuffling. They
include for instance the Thue-Morse word and all Sturmian words of intercept
$0<\rho <1$ (while those of intercept $\rho=0$ are not self-shuffling). Our
characterization of self-shuffling Sturmian words can be interpreted
arithmetically in terms of a dynamical embedding and defines an arithmetic
process we call the {\it stepping stone model}. One important feature of
self-shuffling words stems from its morphic invariance, which provides a useful
tool for showing that one word is not the morphic image of another. The notion
of self-shuffling has other unexpected applications particularly in the area of
substitutive dynamical systems. For example, as a consequence of our
characterization of self-shuffling Sturmian words, we recover a number
theoretic result, originally due to Yasutomi, on a classification of pure
morphic Sturmian words in the orbit of the characteristic.


title: Whitehead and Ganea constructions for fibrewise sectional category

abstract:
  We introduce the notion of fibrewise sectional category via a Whitehead-Ganea
construction. Fibrewise sectional category is the analogue of the ordinary
sectional category in the fibrewise setting and also the natural generalization
of the fibrewise unpointed LS category in the sense of Iwase-Sakai. On the
other hand the fibrewise pointed version is the generalization of the fibrewise
pointed LS category in the sense of James-Morris. After giving their main
properties we also establish some comparisons between such two versions.


title: On a class of $h$-Fourier integral operators

abstract:
  In this paper, we study the $L^{2}$-boundedness and $L^{2}$-compactness of a
class of $h$-Fourier integral operators. These operators are bounded
(respectively compact) if the weight of the amplitude is bounded (respectively
tends to $0)$.


title: Ultrafast QND measurements based on diamond-shape artificial atom

abstract:
  We propose a Quantum Non Demolition (QND) read-out scheme for a
superconducting artificial atom coupled to a resonator in a circuit QED
architecture, for which we estimate a very high measurement fidelity without
Purcell effect limitations. The device consists of two transmons coupled by a
large inductance, giving rise to a diamond-shape artificial atom with a logical
qubit and an ancilla qubit interacting through a cross-Kerr like term. The
ancilla is strongly coupled to a transmission line resonator. Depending on the
qubit state, the ancilla is resonantly or dispersively coupled to the
resonator, leading to a large contrast in the transmitted microwave signal
amplitude. This original method can be implemented with state of the art
Josephson parametric amplifier, leading to QND measurements in a few tens of
nanoseconds with fidelity as large as 99.9 %.


title: Vector boson plus multijet production

abstract:
  In this contribution the developments in the description of vector boson plus
jets signatures at hadron colliders in recent years are summarised. Particular
focus is put on its relevance as background to top physics.


title: Clustering in Nuclei from N/Z=1 to N/Z=2

abstract:
  The clustering of nucleons in nuclei is a widespread but elusive phenomenon
for study. Here, we wish to highlight the variety of theoretical approaches,
and demonstrate how they are mutually supportive and complementary. On the
experimental side, we describe recent advances in the study of the classic
cluster nucleus 24Mg. Also, recent studies of clustering in nuclei approaching
the neutron drip line are described. In the region near N/Z=2, both theory and
experiment now suggest that multi-centre cluster structure is important, in
particular for the very neutron rich beryllium isotopes.


title: Identifying Quantum Structures in the Ellsberg Paradox

abstract:
  Empirical evidence has confirmed that quantum effects occur frequently also
outside the microscopic domain, while quantum structures satisfactorily model
various situations in several areas of science, including biological, cognitive
and social processes. In this paper, we elaborate a quantum mechanical model
which faithfully describes the 'Ellsberg paradox' in economics, showing that
the mathematical formalism of quantum mechanics is capable to represent the
'ambiguity' present in this kind of situations, because of the presence of
'contextuality'. Then, we analyze the data collected in a concrete experiment
we performed on the Ellsberg paradox and work out a complete representation of
them in complex Hilbert space. We prove that the presence of quantum structure
is genuine, that is, 'interference' and 'superposition' in a complex Hilbert
space are really necessary to describe the conceptual situation presented by
Ellsberg. Moreover, our approach sheds light on 'ambiguity laden' decision
processes in economics and decision theory, and allows to deal with different
Ellsberg-type generalizations, e.g., the 'Machina paradox'.


title: Field Theory of Primaries in W_N Minimal Models

abstract:
  For W_N minimal model CFT's at Large N, we formulate a nonlinear field theory
of primary operators. A classification of single-trace operators is given first
based on which an interacting field theory operating in Fock space is built. A
hamiltonian is constructed with the property that it reproduces exactly the
spectrum of conformal dimensions of all the primaries. This field theory is
characterized by cubic (and quartic) interactions with G=1/N as an interaction
parameter. It is seen that the 1/N nonlinear representation contains the
interactions and structure known from Matrix-vector models.


title: Spin currents in a coherent exciton gas

abstract:
  Spin currents and spin textures are observed in a coherent gas of indirect
excitons. Applied magnetic fields bend the spin current trajectories and
transform patterns of linear polarization from helical to spiral and patterns
of circular polarization from four-leaf to bell-like-with-inversion.


title: A Spectral Atlas of HII Galaxies in the Near-Infrared

abstract:
  Recent models show that TP-AGB stars should dominate the NIR spectra of
populations 0.3 to 2 Gyr old, leaving unique signatures that can be used to
detect young/intermediate stellar population in galaxies. However, no
homogeneous database of star-forming galaxies is available in the NIR to fully
explore these results. With this in mind, we study the NIR spectra of a sample
of 23 HII and starburst galaxies, aimed at characterizing the most prominent
spectral features and continuum shape in the 0.8-2.4 micron region of these
objects. Spectral indices are derived for the relevant absorption lines/bands
and a comparison with optical indices of the same sample available in the
literature is made. We found no correlation between the optical and the NIR
indexes. This is probably due to the differences in aperture between these two
sets of data. That result is further supported by the absence or weakness of
emission lines in the NIR for a subsample galaxies, while in the optical the
emission lines are strong and clear, which means that the ionisation source in
many of these galaxies is not nuclear, but circumnuclear or located in hot
spots. We detected important signatures predicted for a stellar population
dominated by the TP-AGBs, like CN 1.1 micron and CO 2.3 micron. In at least one
galaxy (NGC 4102) the CN band at 1.4 micron was detected for the first time. We
also detect TiO and ZrO bands that have never been reported before in
extragalactic sources. The shape of the continuum emission is found to be
strongly correlated to the presence/lack of emission lines. An observational
template for the star-forming galaxies is derived to be used as a benchmark of
stellar population(s) in starburst galaxies against which to compare near-IR
spectroscopy of different types of galaxies, especially those with AGN activity
and/or those at high-redshift.


title:
CMOS-compatible graphene photodetector covering all optical
  communication bands

abstract:
  Optical interconnects are becoming attractive alternatives to electrical
wiring in intra- and inter-chip communication links. Particularly, the
integration with silicon complementary metal-oxide-semiconductor (CMOS)
technology has received considerable interest due to the ability of
cost-effective integration of electronics and optics on a single chip. While
silicon enables the realization of optical waveguides and passive components,
the integration of another, optically absorbing, material is required for
photodetection. Germanium or compound semiconductors are traditionally used for
this purpose; their integration with silicon technology, however, faces major
challenges. Recently, graphene has emerged as a viable alternative for
optoelectronic applications, including photodetection. Here, we demonstrate an
ultra-wideband CMOS-compatible photodetector based on graphene. We achieve
multi-gigahertz operation over all fiber-optic telecommunication bands, beyond
the wavelength range of strained germanium photodetectors, whose responsivity
is limited by their bandgap. Our work complements the recent demonstration of a
CMOS-integrated graphene electro-optical modulator, paving the way for
carbon-based optical interconnects.


title:
Cancer Diagnosis with QUIRE: QUadratic Interactions among infoRmative
  fEatures

abstract:
  Responsible for many complex human diseases including cancers, disrupted or
abnormal gene interactions can be identified through their expression changes
correlating with the progression of a disease. However, the examination of all
possible combinatorial interactions between gene features in a genome-wide
case-control study is computationally infeasible as the search space is
exponential in nature.
  In this paper, we propose a novel computational approach, QUIRE, to identify
discriminative complex interactions among informative gene features for cancer
diagnosis. QUIRE works in two stages, where it first identifies functionally
relevant feature groups for the disease and, then explores the search space
capturing the combinatorial relationships among the genes from the selected
informative groups. Using QUIRE, we explore the differential patterns and the
interactions among informative gene features in three different types of
cancers, Renal Cell Carcinoma(RCC), Ovarian Cancer(OVC) and Colorectal Cancer
(CRC). Our experimental results show that QUIRE identifies gene-gene
interactions that can better identify the different cancer stages of samples
and can predict CRC recurrence and death from CRC more successfully, as
compared to other state-of-the-art feature selection methods. A literature
survey shows that many of the interactions identified by QUIRE play important
roles in the development of cancer.


title: Single top production in association with a Z boson at the LHC

abstract:
  We present results for the production of a Z boson in association with single
top at next-to-leading order (NLO), including the decay of the top quark and
the Z boson. This electroweak process gives rise to the trilepton signature
l+l-l'+- + jets + missing energy. We present results for this signature and
show that the rate is competitive with the contribution of the mixed strong and
electroweak production process, ttZ. As such it should be observable in the
full data sample from LHC running at $\sqrt{s}=8$ TeV. The single top + Z
process is a hitherto unconsidered irreducible background in searches for
flavour changing neutral current decays of the top quark in tt production. For
a selection of cuts used at the LHC involving a b-tag it is the dominant
background. In an appendix we also briefly discuss the impact of NLO
corrections on the related tH process.


title:
Technical Report: Cooperative Multi-Target Localization With Noisy
  Sensors

abstract:
  This technical report is an extended version of the paper 'Cooperative
Multi-Target Localization With Noisy Sensors' accepted to the 2013 IEEE
International Conference on Robotics and Automation (ICRA).
  This paper addresses the task of searching for an unknown number of static
targets within a known obstacle map using a team of mobile robots equipped with
noisy, limited field-of-view sensors. Such sensors may fail to detect a subset
of the visible targets or return false positive detections. These measurement
sets are used to localize the targets using the Probability Hypothesis Density,
or PHD, filter. Robots communicate with each other on a local peer-to-peer
basis and with a server or the cloud via access points, exchanging measurements
and poses to update their belief about the targets and plan future actions. The
server provides a mechanism to collect and synthesize information from all
robots and to share the global, albeit time-delayed, belief state to robots
near access points. We design a decentralized control scheme that exploits this
communication architecture and the PHD representation of the belief state.
Specifically, robots move to maximize mutual information between the target set
and measurements, both self-collected and those available by accessing the
server, balancing local exploration with sharing knowledge across the team.
Furthermore, robots coordinate their actions with other robots exploring the
same local region of the environment.


title: A Massive Protostar Forming by Ordered Collapse of a Dense, Massive Core

abstract:
  We present 30 and 40 micron imaging of the massive protostar G35.20-0.74 with
SOFIA-FORCAST. The high surface density of the natal core around the protostar
leads to high extinction, even at these relatively long wavelengths, causing
the observed flux to be dominated by that emerging from the near-facing outflow
cavity. However, emission from the far-facing cavity is still clearly detected.
We combine these results with fluxes from the near-infrared to mm to construct
a spectral energy distribution (SED). For isotropic emission the bolometric
luminosity would be 3.3x10^4 Lsun. We perform radiative transfer modeling of a
protostar forming by ordered, symmetric collapse from a massive core bounded by
a clump with high mass surface density, Sigma_cl. To fit the SED requires
protostellar masses ~20-34 Msun depending on the outflow cavity opening angle
(35 - 50 degrees), and Sigma_cl ~ 0.4-1 g cm-2. After accounting for the
foreground extinction and the flashlight effect, the true bolometric luminosity
is ~ (0.7-2.2)x10^5 Lsun. One of these models also has excellent agreement with
the observed intensity profiles along the outflow axis at 10, 18, 31 and 37
microns. Overall our results support a model of massive star formation
involving the relatively ordered, symmetric collapse of a massive, dense core
and the launching bipolar outflows that clear low density cavities. Thus a
unified model may apply for the formation of both low and high mass stars.


title: Optimal frame completions with prescribed norms for majorization

abstract:
  Given a finite sequence of vectors $\mathcal F_0$ in $\C^d$ we characterize
in a complete and explicit way the optimal completions of $\mathcal F_0$
obtained by adding a finite sequence of vectors with prescribed norms, where
optimality is measured with respect to majorization (of the eigenvalues of the
frame operators of the completed sequence). Indeed, we construct (in terms of a
fast algorithm) a vector - that depends on the eigenvalues of the frame
operator of the initial sequence $\cF_0$ and the sequence of prescribed norms -
that is a minimum for majorization among all eigenvalues of frame operators of
completions with prescribed norms. Then, using the eigenspaces of the frame
operator of the initial sequence $\cF_0$ we describe the frame operators of all
optimal completions for majorization. Hence, the concrete optimal completions
with prescribed norms can be obtained using recent algorithmic constructions
related with the Schur-Horn theorem.
  The well known relation between majorization and tracial inequalities with
respect to convex functions allow to describe our results in the following
equivalent way: given a finite sequence of vectors $\mathcal F_0$ in $\C^d$ we
show that the completions with prescribed norms that minimize the convex
potential induced by a strictly convex function are structural minimizers, in
the sense that they do not depend on the particular choice of the convex
potential.


title: ScalienDB: Designing and Implementing a Distributed Database using Paxos

abstract:
  ScalienDB is a scalable, replicated database built on top of the Paxos
algorithm. It was developed from 2010 to 2012, when the startup backing it
failed. This paper discusses the design decisions of the distributed database,
describes interesting parts of the C++ codebase and enumerates lessons learned
putting ScalienDB into production at a handful of clients. The source code is
available on Github under the AGPL license, but it is no longer developed or
maintained.


title:
The Flexibility and Musculature of the Ostrich Neck: Implications for
  the Feeding Ecology and Reconstruction of the Sauropoda
  (Dinosauria:Saurischia)

abstract:
  The Sauropoda were the largest terrestrial animals ever to have lived on this
planet. As their nutritional requirements were so huge, their diet holds sway
over the ecology of many Mesozoic herbivores. The diet of the sauropods is
limited by their feeding envelope, which in turn is governed by the posture and
flexibility of their elongate necks. Yet the exact nature of the flexibility
and posture of the neck has been a contentious issue. Previous studies have
utilised computer models of dry bone, mechanical principles or the flexibility
of the necks of extant animals. However, the effect of the musculature of the
neck has yet to be investigated. Through measurements of the flexibility of the
ostrich neck after cumulative tissue removal, analyses of the muscle attachment
sites of the ostrich and sauropods, and testing of the Osteological Neutral
Pose model, this study attempts to rectify this situation. The ostrich neck was
shown to have three sections of flexibility; a slightly flexible anterior
section, a very flexible middle section and a stiff posterior section. The
Osteological Neutral Pose did not show these sections, and was shown to
potentially overestimate and underestimate flexibility. It was also found that
the inter-vertebral space could account for varying estimates of flexibility,
and that sauropods would have proportionally more muscle mass at the base of
the neck in relation to the ostrich. Ultimately, it was shown that the tissues
of the neck place the limits of flexibility, and that zygapophyseal overlap
does not indicate the flexibility of the neck. Should the Osteological Neutral
Pose affect sauropod flexibility estimates in the same manner as that of the
ostrich (a general overestimate), then the sauropods would have a more limited
feeding envelope than previously thought, allowing for greater niche
partitioning between groups.


title: GEMINI: A Generic Multi-Modal Natural Interface Framework for Videogames

abstract:
  In recent years videogame companies have recognized the role of player
engagement as a major factor in user experience and enjoyment. This encouraged
a greater investment in new types of game controllers such as the WiiMote, Rock
Band instruments and the Kinect. However, the native software of these
controllers was not originally designed to be used in other game applications.
This work addresses this issue by building a middleware framework, which maps
body poses or voice commands to actions in any game. This not only warrants a
more natural and customized user-experience but it also defines an
interoperable virtual controller. In this version of the framework, body poses
and voice commands are respectively recognized through the Kinect's built-in
cameras and microphones. The acquired data is then translated into the native
interaction scheme in real time using a lightweight method based on spatial
restrictions. The system is also prepared to use Nintendo's Wiimote as an
auxiliary and unobtrusive gamepad for physically or verbally impractical
commands. System validation was performed by analyzing the performance of
certain tasks and examining user reports. Both confirmed this approach as a
practical and alluring alternative to the game's native interaction scheme. In
sum, this framework provides a game-controlling tool that is totally
customizable and very flexible, thus expanding the market of game consumers.


title: Upper bounds for the complexity of torus knot complements

abstract:
  We establish upper bounds for the complexity of Seifert fibered manifolds
with nonempty boundary. In particular, we obtain potentially sharp bounds on
the complexity of torus knot complements.


title: Effective dynamics of a classical point charge

abstract:
  The effective Lagrangian of a point charge is derived by eliminating the
electromagnetic field within the framework of the classical closed time path
formalism. The short distance singularity of the electromagnetic field is
regulated by an UV cutoff. The Abraham-Lorentz force is recovered and its
similarity to anomalies is underlined. The full cutoff-dependent linearized
equation of motion is obtained, no runaway trajectories are found but the
effective dynamics shows acausality if the cutoff is beyond the classical
charge radius. The strength of the radiation reaction force displays a pole in
its cutoff-dependence in a manner reminiscent of the Landau-pole of
perturbative QED. Similarity between the dynamical breakdown of the time
reversal invariance and dynamical symmetry breaking is pointed out.


title: Upper bounds on mixing rates

abstract:
  We prove upper bounds on the rate, called "mixing rate", at which the von
Neumann entropy of the expected density operator of a given ensemble of states
changes under non-local unitary evolution. For an ensemble consisting of two
states, with probabilities of p and 1-p, we prove that the mixing rate is
bounded above by 4\sqrt{p(1-p)} for any Hamiltonian of norm 1. For a general
ensemble of states with probabilities distributed according to a random
variable X and individually evolving according to any set of bounded
Hamiltonians, we conjecture that the mixing rate is bounded above by a Shannon
entropy of a random variable X. For this general case we prove an upper bound
that is independent of the dimension of the Hilbert space on which states in
the ensemble act.


title:
Classification of Radial Solutions to Liouville Systems with
  Singularities

abstract:
  Let $A=(a_{ij})_{n\times n}$ be a nonnegative, symmetric, irreducible and
invertible matrix. We prove the existence and uniqueness of radial solutions to
the following Liouville system with singularity: $$\{{array}{ll} \Delta
u_i+\sum_{j=1}^n a_{ij}|x|^{\beta_j}e^{u_j(x)}=0,\quad \mathbb R^2, \quad
i=1,...,n \int_{\mathbb R^2}|x|^{\beta_i}e^{u_i(x)}dx<\infty, \quad i=1,...,n
{array}. $$ where $\beta_1,...,\beta_n$ are constants greater than -2. If all
$\beta_i$s are negative we prove that all solutions are radial and the
linearized system is non-degenerate.


title: The structure of graphs not admitting a fixed immersion

abstract:
  We present an easy structure theorem for graphs which do not admit an
immersion of the complete graph. The theorem motivates the definition of a
variation of tree decompositions based on edge cuts instead of vertex cuts
which we call tree-cut decompositions. We give a definition for the width of
tree-cut decompositions, and using this definition along with the structure
theorem for excluded clique immersions, we prove that every graph either has
bounded tree-cut width or admits an immersion of a large wall.


title:
Symbolic control of stochastic systems via approximately bisimilar
  finite abstractions

abstract:
  Symbolic approaches to the control design over complex systems employ the
construction of finite-state models that are related to the original control
systems, then use techniques from finite-state synthesis to compute controllers
satisfying specifications given in a temporal logic, and finally translate the
synthesized schemes back as controllers for the concrete complex systems. Such
approaches have been successfully developed and implemented for the synthesis
of controllers over non-probabilistic control systems. In this paper, we extend
the technique to probabilistic control systems modeled by controlled stochastic
differential equations. We show that for every stochastic control system
satisfying a probabilistic variant of incremental input-to-state stability, and
for every given precision $\varepsilon>0$, a finite-state transition system can
be constructed, which is $\varepsilon$-approximately bisimilar (in the sense of
moments) to the original stochastic control system. Moreover, we provide
results relating stochastic control systems to their corresponding finite-state
transition systems in terms of probabilistic bisimulation relations known in
the literature. We demonstrate the effectiveness of the construction by
synthesizing controllers for stochastic control systems over rich
specifications expressed in linear temporal logic. The discussed technique
enables a new, automated, correct-by-construction controller synthesis approach
for stochastic control systems, which are common mathematical models employed
in many safety critical systems subject to structured uncertainty and are thus
relevant for cyber-physical applications.


title: Information transfer of an Ising model on a brain network

abstract:
  We implement the Ising model on a structural connectivity matrix describing
the brain at a coarse scale. Tuning the model temperature to its critical
value, i.e. at the susceptibility peak, we find a maximal amount of total
information transfer between the spin variables. At this point the amount of
information that can be redistributed by some nodes reaches a limit and the net
dynamics exhibits signature of the law of diminishing marginal returns, a
fundamental principle connected to saturated levels of production. Our results
extend the recent analysis of dynamical oscillators models on the connectome
structure, taking into account lagged and directional influences, focusing only
on the nodes that are more prone to became bottlenecks of information. The
ratio between the outgoing and the incoming information at each node is related
to the number of incoming links.


title: A second-order stock market model

abstract:
  A first-order model for a stock market assigns to each stock a return
parameter and a variance parameter that depend only on the rank of the stock. A
second-order model assigns these parameters based on both the rank and the name
of the stock. First- and second-order models exhibit stability properties that
make them appropriate as a backdrop for the analysis of the idiosyncratic
behavior of individual stocks. Methods for the estimation of the parameters of
second-order models are developed in this paper.


title:
Continuous melting and thermal-history-dependent freezing in the
  confined Na-K eutectic alloy

abstract:
  23Na NMR studies of the Na-K eutectic alloy embedded into porous glass with 7
nm pores showed that melting of Na2K confined nanoparticles is a continuous
process with smooth changes in the Knight shift of a narrow resonance line and
nuclear spin relaxation between those in the crystalline and liquid states. The
intermediate state which occurs upon melting is stable and more favorable than
the liquid state. The inverse freezing transformation can be sharp as at a
first order transition or continuous depending on the initial temperature of
cooling. The results suggest revision of theoretical predictions for the
melting and freezing transitions in confined geometry.


title: List Coloring Triangle-Free Hypergraphs

abstract:
  A triangle in a hypergraph is a collection of distinct vertices u,v,w and
distinct edges e,f,g with u,v \in e, v,w \in f, w,u \in g, and \{u,v,w\} \cap e
\cap f \cap g=\emptyset. The i-degree of a vertex in a hypergraph is the number
of edges of size i containing it. We prove that every triangle-free hypergraph
of rank three (edges have size two or three) with maximum 3-degree \Delta_3 and
maximum 2-degree \Delta_2 has list chromatic number at most c max{\Delta_2/
log{\Delta_2}}, (\Delta_3 / log{\Delta_3})^(1/2)} for some absolute positive
constant c. This generalizes a result of Johansson and a result of Frieze and
the second author.


title: Rational singular loci of nilpotent varieties

abstract:
  We present two methods for computing the rational singular locus of the
closure of a nilpotent orbit in a complex semisimple Lie algebra and give a
number of interesting examples.


title: Thermodynamics of "exotic" BTZ black holes

abstract:
  A number of three-dimensional (3D) gravity models, such as 3D conformal
gravity, admit "exotic" black hole solutions: the metric is the same as the BTZ
metric of 3D Einstein gravity but with reversed roles for mass and angular
momentum, and an entropy proportional to the length of the inner horizon
instead of the event horizon. Here we show that the BTZ solutions of the
"exotic" 3D Einstein gravity (with parity-odd action but Einstein field
equations) are exotic black holes, and we investigate their thermodynamics. The
first and second laws of black hole thermodynamics still apply, and the entropy
still has a statistical interpretation.


title: Kinematic Moment of Inertia of e-e Rare Earths Nuclei

abstract:
  The kinematic moment of inertia of the rare earth even-even nuclei was
calculated using three parametric energy based expression. The plot of
kinematic moment of inertia versus nuclear spin shows a better sensitivity to
back bending than energy plot.


title:
An Efficient Implementation of the Ensemble Kalman Filter Based on an
  Iterative Sherman-Morrison Formula

abstract:
  We present a practical implementation of the ensemble Kalman (EnKF) filter
based on an iterative Sherman-Morrison formula. The new direct method exploits
the special structure of the ensemble-estimated error covariance matrices in
order to efficiently solve the linear systems involved in the analysis step of
the EnKF. The computational complexity of the proposed implementation is
equivalent to that of the best EnKF implementations available in the literature
when the number of observations is much larger than the number of ensemble
members. Even when this conditions is not fulfilled, the proposed method is
expected to perform well since it does not employ matrix decompositions.
Computational experiments using the Lorenz 96 and the oceanic quasi-geostrophic
models are performed in order to compare the proposed algorithm with EnKF
implementations that use matrix decompositions. In terms of accuracy, the
results of all implementations are similar. The proposed method is considerably
faster than other EnKF variants, even when the number of observations is large
relative to the number of ensemble members.


title:
Probing Two-Field Open Inflation by Resonant Signals in Correlation
  Functions

abstract:
  We derive oscillatory signals in correlation functions in two-field open
inflation by means of the in-in formalism; such signatures are caused by
resonances between oscillations in the tunnelling field and fluctuations in the
inflaton during the curvature dominated, intermediate and subsequent
inflationary regime. While amplitudes are model-dependent, we find distinct
oscillations in the power and bi-spectrum that can act as a direct probe of the
curvature dominated phase and thus, indirectly, strengthen the claim of the
string landscape if they were observed. We comment on the prospects of
detecting these tell-tale signs in current experiments, which is challenging,
but not impossible.
  At the technical level, we pay special attention to the applicability
conditions for truncation fluctuations to the light (inflaton) field and derive
upper limits on the oscillation amplitude of the heavy field. A violation of
these bounds requires a multi-field analysis at the perturbed level.


title: High-Resolution Observations and the Physics of High-Velocity Cloud A0

abstract:
  The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km/s)
has been mapped with a 9.1 arcmin resolution. Gaussian decomposition of the
profiles is used to separately map families of components defined by
similarities in center velocities and line widths. About 70% of the HI gas is
in the form of a narrow, twisted filament whose typical line widths are of
order 24 km/s. Many bright features with narrow line widths of order 6 km/s,
clouds, are located in and near the filament. A third category with properties
between those of the filament and clouds appears in the data. The clouds are
not always co-located with the broader line width filament emission as seen
projected on the sky. Under the assumption that magnetic fields underlie the
presence of the filament, a theorem is developed for its stability in terms of
a toroidal magnetic field generated by the flow of gas along field lines. It is
suggested that the axial magnetic field strength may be derived from the excess
line width of the HI emission over and above that due to kinetic temperature by
invoking the role of Alfven waves that create what is in essence a form of
magnetic turbulence. At a distance of 200 pc the axial and the derived toroidal
magnetic field strengths in the filament are then about 6 microGauss while for
the clouds they are about 4 microGauss. The dependence of the derived field
strength on distance is discussed.


title: A controlling norm for energy-critical Schr\"odinger maps

abstract:
  We consider energy-critical Schroedinger maps with target either the sphere
S^2 or hyperbolic plane H^2 and establish that a unique solution may be
continued so long as a certain space-time L^4 norm remains bounded. This
reduces the large data global wellposedness problem to that of controlling this
norm.


title: The electromagnetic momentum of static charge-current distributions

abstract:
  The origin of electromagnetic momentum for general static charge-current
distributions is examined. The electromagnetic momentum for static
electromagnetic fields is derived by implementing conservation of momentum for
the sum of mechanical momentum and electromagnetic momentum. The external force
required to keep matter at rest during the production of the final static
configuration produces the electromagnetic momentum. Examples of the
electromagnetic momentum in static electric and magnetic fields are given. The
`center of energy' theorem is shown to be violated by electromagnetic momentum.
`Hidden momentum' is shown to be generally absent, and not to cancel
electromagnetic momentum.


title:
Observation of a nanophase segregation in LiCl aqueous solutions from
  Transient Grating Experiments

abstract:
  Transient Grating experiments performed on supercooled LiCl, RH2O solutions
with R>6 reveal the existence of a strong, short time, extra signal which
superposes to the normal signal observed for the R=6 solution and other glass
forming systems. This extra signal shows up below 190 K, its shape and the
associated timescale depend only on temperature, while its intensity increases
with R. We show that the origin of this signal is a phase separation between
clusters with a low solute concentration and the remaining, more concentrated,
solution. Our analysis demonstrates that these clusters have a nanometer size
and a composition which are rather temperature independent, while increasing R
simply increases the number of these clusters.


title:
Finite group algebras of nilpotent groups: a complete set of orthogonal
  primitive idempotents

abstract:
  We provide an explicit construction for a complete set of orthogonal
primitive idempotents of finite group algebras over nilpotent groups.
Furthermore, we give a complete set of matrix units in each simple epimorphic
image of a finite group algebra of a nilpotent group.


title: Anomalous CO2 Ice Toward HOPS-68: A Tracer of Protostellar Feedback

abstract:
  We report the detection of a unique CO2 ice band toward the deeply embedded,
low-mass protostar HOPS-68. Our spectrum, obtained with the Infrared
Spectrograph onboard the Spitzer Space Telescope, reveals a 15.2 micron CO2 ice
bending mode profile that cannot modeled with the same ice structure typically
found toward other protostars. We develop a modified CO2 ice profile
decomposition, including the addition of new high-quality laboratory spectra of
pure, crystalline CO2 ice. Using this model, we find that 87-92% of the CO2 is
sequestered as spherical, CO2-rich mantles, while typical interstellar ices
show evidence of irregularly-shaped, hydrogen-rich mantles. We propose that (1)
the nearly complete absence of unprocessed ices along the line-of-sight is due
to the flattened envelope structure of HOPS-68, which lacks cold absorbing
material in its outer envelope, and possesses an extreme concentration of
material within its inner (10 AU) envelope region and (2) an energetic event
led to the evaporation of inner envelope ices, followed by cooling and
re-condensation, explaining the sequestration of spherical, CO2 ice mantles in
a hydrogen-poor mixture. The mechanism responsible for the sublimation could be
either a transient accretion event or shocks in the interaction region between
the protostellar outflow and envelope. The proposed scenario is consistent with
the rarity of the observed CO2 ice profile, the formation of nearly pure CO2
ice, and the production of spherical ice mantles. HOPS-68 may therefore provide
a unique window into the protostellar feedback process, as outflows and heating
shape the physical and chemical structure of protostellar envelopes and
molecular clouds.


title: New stellar constraints on dark photons

abstract:
  We consider the stellar production of vector states V within the minimal
model of "dark photons". We show that when the Stuckelberg mass of the dark
vector becomes smaller than plasma frequency, the emission rate is dominated by
the production of the longitudinal modes of V, and scales as \kappa^2 m_V^2,
where \kappa and m_V are the mixing angle with the photon and the mass of the
dark state. This is in contrast with earlier erroneous claims in the literature
that the emission rate decouples as the forth power of the mass. We derive
ensuing constraints on the (\kappa, m_V) parameter space by calculating the
cooling rates for the Sun and red giant stars. We find that stellar bounds for
m_V < 10 eV are significantly strengthened, to the extent that all current
"light-shining-through-wall" experiments find themselves within deeply excluded
regions.


title:
Big Black Hole, Little Neutron Star: Magnetic Dipole Fields in the
  Rindler Spacetime

abstract:
  As a black hole and neutron star approach during inspiral, the field lines of
a magnetized neutron star eventually thread the black hole event horizon and a
short-lived electromagnetic circuit is established. The black hole acts as a
battery that provides power to the circuit, thereby lighting up the pair just
before merger. Although originally suggested as a promising electromagnetic
counterpart to gravitational-wave detection, the luminous signals are promising
more generally as potentially detectable phenomena, such as short gamma-ray
bursts. To aid in the theoretical understanding, we present analytic solutions
for the electromagnetic fields of a magnetic dipole in the presence of an event
horizon. In the limit that the neutron star is very close to a Schwarzschild
horizon, the Rindler limit, we can solve Maxwell's equations exactly for a
magnetic dipole on an arbitrary worldline. We present these solutions here and
investigate a proxy for a small segment of the neutron star orbit around a big
black hole. We find that the voltage the black hole battery can provide is in
the range ~10^16 statvolts with a projected luminosity of 10^42 ergs/s for an
M=10M_sun black hole, a neutron star with a B-field of 10^12 G, and an orbital
velocity ~0.5c at a distance of 3M from the horizon. Larger black holes provide
less power for binary separations at a fixed number of gravitational radii. The
black hole/neutron star system therefore has a significant power supply to
light up various elements in the circuit possibly powering jets, beamed
radiation, or even a hot spot on the neutron star crust.


title: Diffuse X-ray Emission from Planetary Nebulae with Nebular O VI

abstract:
  The presence of O VI ions can be indicative of plasma temperatures of a few
times 10^5 K that is expected in heat conduction layers between the hot shocked
stellar wind gas at several 10^6 K and the cooler (~10,000 K) nebular gas of
planetary nebulae (PNe). We have used FUSE observations of PNe to search for
nebular O VI emission or absorption as a diagnostic of conduction layer to
ensure the presence of hot interior gas. Three PNe showing nebular O VI, namely
IC 418, NGC 2392, and NGC 6826, have been selected for Chandra observations and
diffuse X-ray emission is indeed detected in each of these PNe. Among the
three, NGC 2392 has peculiarly high diffuse X-ray luminosity and plasma
temperature compared with those expected from its stellar wind's mechanical
luminosity and terminal velocity. The limited effects of heat conduction on the
plasma temperature of a hot bubble at the low terminal velocity of the stellar
wind of NGC 2392 may partially account for its high plasma temperature, but the
high X-ray luminosity needs to be powered by processes other than the observed
stellar wind, probably caused by the presence of an unseen binary companion of
the CSPN of NGC 2392. We have compiled relevant information on the X-ray,
stellar, and nebular properties of PNe with a bubble morphology and found that
the expectations of bubble models including heat conduction compare favorably
with the present X-ray observations of hot bubbles around H-rich CSPNe, but
have notable discrepancies for those around H-poor [WR] CSPNe. We note that PNe
with more massive central stars can produce hotter plasma and higher X-ray
surface brightness inside central hot bubbles.


title:
The Dirichlet problem for p-harmonic functions with respect to the
  Mazurkiewicz boundary

abstract:
  In this paper we develop the Perron method for solving the Dirichlet problem
for the analog of the p-Laplacian, i.e. for p-harmonic functions, with
Mazurkiewicz boundary values. The setting considered here is that of metric
spaces, where the boundary of the domain in question is replaced with the
Mazurkiewicz boundary. Resolutivity for Sobolev and continuous functions, as
well as invariance results for perturbations on small sets, are obtained. We
use these results to improve the known resolutivity and invariance results for
functions on the standard (metric) boundary. We also illustrate the results of
this paper by discussing several examples.


title:
On the convergence exponent of the special integral of two-dimensionl
  Tarry's problem

abstract:
  In this article new bounds for the convergence exponent of the two
dimensional Tarry's problem are given.


title: Power Strip Packing of Malleable Demands in Smart Grid

abstract:
  We consider a problem of supplying electricity to a set of $\mathcal{N}$
customers in a smart-grid framework. Each customer requires a certain amount of
electrical energy which has to be supplied during the time interval $[0,1]$. We
assume that each demand has to be supplied without interruption, with possible
duration between $\ell$ and $r$, which are given system parameters ($\ell\le
r$). At each moment of time, the power of the grid is the sum of all the
consumption rates for the demands being supplied at that moment. Our goal is to
find an assignment that minimizes the {\it power peak} - maximal power over
$[0,1]$ - while satisfying all the demands. To do this first we find the lower
bound of optimal power peak. We show that the problem depends on whether or not
the pair $\ell, r$ belongs to a "good" region $\mathcal{G}$. If it does - then
an optimal assignment almost perfectly "fills" the rectangle $time \times power
= [0,1] \times [0, A]$ with $A$ being the sum of all the energy demands - thus
achieving an optimal power peak $A$. Conversely, if $\ell, r$ do not belong to
$\mathcal{G}$, we identify the lower bound $\bar{A} >A$ on the optimal value of
power peak and introduce a simple linear time algorithm that almost perfectly
arranges all the demands in a rectangle $[0, A /\bar{A}] \times [0, \bar{A}]$
and show that it is asymptotically optimal.


title:
Extraction of Axial Mass and Strangeness Values from the MiniBooNE
  Neutral Current Elastic Cross Section Measurement

abstract:
  Results of the analysis of the MiniBooNE experiment data for the neutral
current elastic neutrino scattering off the $CH_{2}$ target with the NuWro
Monte Carlo generator are presented. Inclusion in the NuWro the two body
current contribution leads to the axial mass value $M_A = 1.10^{+0.13}_{-0.15}$
GeV consistent with the older evaluations based on the neutrino-deuteron
scattering data. The strange quark contribution to the nucleon spin is
estimated with the value $g_A^s = -0.4^{+0.5}_{-0.3}$.


title: Scattering Amplitude of {\pi}N on the Second Sheet

abstract:
  We propose parameterization procedures of the scattering amplitude
f_{1+}^{3}(s)) with a view to extracting the pole parameters from data in the
elastic region of {\pi}N scattering. This is achieved by considering the
analyticity properties of partial wave amplitudes directly and writing
dispersion relations for the amplitude explicitly.


title: Identifying trends in word frequency dynamics

abstract:
  The word-stock of a language is a complex dynamical system in which words can
be created, evolve, and become extinct. Even more dynamic are the short-term
fluctuations in word usage by individuals in a population. Building on the
recent demonstration that word niche is a strong determinant of future rise or
fall in word frequency, here we introduce a model that allows us to distinguish
persistent from temporary increases in frequency. Our model is illustrated
using a 10^8-word database from an online discussion group and a 10^11-word
collection of digitized books. The model reveals a strong relation between
changes in word dissemination and changes in frequency. Aside from their
implications for short-term word frequency dynamics, these observations are
potentially important for language evolution as new words must survive in the
short term in order to survive in the long term.

categories: physics.soc-ph cond-mat.dis-nn cs.CL q-bio.PE


title: Dynamical phase transitions after quenches in non-integrable models

abstract:
  We investigate the dynamics following sudden quenches across quantum critical
points belonging to different universality classes. Specifically, we use matrix
product state methods to study the quantum Ising chain in the presence of two
additional terms which break integrability. We find that in all models the rate
function for the return probability to the initial state becomes a non-analytic
function of time in the thermodynamic limit. This so-called `dynamical phase
transition' was first observed in a recent work by Heyl, Polkovnikov, and
Kehrein [Phys. Rev. Lett. 110, 135704 (2013)] for the exactly-solvable quantum
Ising chain, which can be mapped to free fermions. Our results for `interacting
theories' indicate that non-analytic dynamics is a generic feature of sudden
quenches across quantum critical points. We discuss potential connections to
the dynamics of the order parameter.


title: A framework for automated PDE-constrained optimisation

abstract:
  A generic framework for the solution of PDE-constrained optimisation problems
based on the FEniCS system is presented. Its main features are an intuitive
mathematical interface, a high degree of automation, and an efficient
implementation of the generated adjoint model. The framework is based upon the
extension of a domain-specific language for variational problems to cleanly
express complex optimisation problems in a compact, high-level syntax. For
example, optimisation problems constrained by the time-dependent Navier-Stokes
equations can be written in tens of lines of code. Based on this high-level
representation, the framework derives the associated adjoint equations in the
same domain-specific language, and uses the FEniCS code generation technology
to emit parallel optimised low-level C++ code for the solution of the forward
and adjoint systems. The functional and gradient information so computed is
then passed to the optimisation algorithm to update the parameter values. This
approach works both for steady-state as well as transient, and for linear as
well as nonlinear governing PDEs and a wide range of functionals and control
parameters. We demonstrate the applicability and efficiency of this approach on
classical textbook optimisation problems and advanced examples.


title: Double quantum dot in a quantum dash: optical properties

abstract:
  We study the optical properties of highly anisotropic quantum dot structures
(quantum dashes) characterized by the presence of two trapping centers located
along the structure. Such a system can exhibit some of the properties
characteristic for double quantum dots. We show that sub- and super-radiant
states can form for certain quantum dash geometries, which is manifested by a
pronounced transfer of intensity between spectral lines, accompanied by the
appearance of strong electron-hole correlations. We also compare exciton
absorption spectra and polarization properties of a system with a single and
double trapping center and show how the geometry of multiple trapping centers
influences the optical properties of the system. We show that for a broad range
of trapping geometries the relative absorption intensity of the ground state is
larger than that of the lowest excited states, contrary to the quantum dash
systems characterized by a single trapping center. Thus, optical properties of
these structures are determined by fine details of their morphology.


title: Landau Level Mixing and the Fractional Quantum Hall Effect

abstract:
  We derive effective Hamiltonians for the fractional quantum Hall effect in
n=0 and n=1 Landau levels that account perturbatively for Landau level mixing
by electron-electron interactions. To second order in the ratio of
electron-electron interaction to cyclotron energy, Landau level mixing is
accounted for by constructing effective interaction Hamiltonians that include
two-body and three-body contributions characterized by Haldane
pseudopotentials. Our study builds upon previous treatments, using as a
stepping stone the observation that the effective Hamiltonian is fully
determined by the few-body problem with N=2 and N=3 electrons in the partially
filled Landau level. For the n=0 case we use a first quantization approach to
provide a compact and transparent derivation of the effective Hamiltonian which
captures a class of virtual processes omitted in earlier derivations of
Landau-level-mixing corrected Haldane pseudopotentials.


title: The automorphism group functor of the N=4 Lie conformal superalgebra

abstract:
  In this paper, we study the structure and representability of the
automorphism group functor of the N=4 Lie conformal superalgebra over an
algebraically closed field k of characteristic zero.


title:
Beyond Collisionless Dark Matter: Particle Physics Dynamics for Dark
  Matter Halo Structure

abstract:
  Dark matter (DM) self-interactions have important implications for the
formation and evolution of structure, from dwarf galaxies to clusters of
galaxies. We study the dynamics of self-interacting DM via a light mediator,
focusing on the quantum resonant regime where the scattering cross section has
a non-trivial velocity dependence. While there are long-standing indications
that observations of small scale structure in the Universe are not in accord
with the predictions of collisionless DM, theoretical study and simulations of
DM self-interactions have focused on parameter regimes with simple analytic
solutions for the scattering cross section, with constant or classical velocity
(and no angular) dependence. We devise a method that allows us to explore the
velocity and angular dependence of self-scattering more broadly, in the
strongly-coupled resonant and classical regimes where many partial modes are
necessary for the achieving the result. We map out the entire parameter space
of DM self-interactions --- and implications for structure observations --- as
a function of the coupling and the DM and mediator masses. We derive a new
analytic formula for describing resonant s-wave scattering. Finally, we show
that DM self-interactions can be correlated with observations of Sommerfeld
enhancements in DM annihilation through indirect detection experiments.


title: A note on quasiconformal maps with Holder-continuous dilatation

abstract:
  Here we give an alternate proof of a sufficient condition due to J. Mateu, J.
Orobitg, and J. Verdera for a quasiconformal map of the plane with dilatation
supported in a smooth domain to be bi-Lipschitz. We also extend this theorem to
cover boundaries with certain types of corners.


title: Robust Image Segmentation in Low Depth Of Field Images

abstract:
  In photography, low depth of field (DOF) is an important technique to
emphasize the object of interest (OOI) within an image. Thus, low DOF images
are widely used in the application area of macro, portrait or sports
photography. When viewing a low DOF image, the viewer implicitly concentrates
on the regions that are sharper regions of the image and thus segments the
image into regions of interest and non regions of interest which has a major
impact on the perception of the image. Thus, a robust algorithm for the fully
automatic detection of the OOI in low DOF images provides valuable information
for subsequent image processing and image retrieval. In this paper we propose a
robust and parameterless algorithm for the fully automatic segmentation of low
DOF images. We compare our method with three similar methods and show the
superior robustness even though our algorithm does not require any parameters
to be set by hand. The experiments are conducted on a real world data set with
high and low DOF images.


title: Enhanced secure key exchange systems based on the Johnson-noise scheme

abstract:
  We introduce seven new versions of the Kirchhoff-Law-Johnson-(like)-Noise
(KLJN) classical physical secure key exchange scheme and a new transient
protocol for practically-perfect security. While these practical improvements
offer progressively enhanced security and/or speed for the non-ideal
conditions, the fundamental physical laws providing the security remain the
same.
  In the "intelligent" KLJN (iKLJN) scheme, Alice and Bob utilize the fact that
they exactly know not only their own resistor value but also the stochastic
time function of their own noise, which they generate before feeding it into
the loop.
  In the "multiple" KLJN (MKLJN) system, Alice and Bob have publicly known
identical sets of different resistors with a proper, publicly known truth table
about the bit-interpretation of their combination. In the "keyed" KLJN (KKLJN)
system, by using secure communication with a formerly shared key, Alice and Bob
share a proper time-dependent truth table for the bit-interpretation of the
resistor situation for each secure bit exchange step during generating the next
key.
  The remaining four KLJN schemes are the combinations of the above protocols
to synergically enhance the security properties. These are: the
"intelligent-multiple" (iMKLJN), the "intelligent-keyed" (iKKLJN), the
"keyed-multiple" (KMKLJN) and the "intelligent-keyed-multiple" (iKMKLJN) KLJN
key exchange systems.
  Finally, we introduce a new transient-protocol offering practically-perfect
security without privacy amplification, which is not needed at practical
applications but it is shown for the sake of ongoing discussions.


title: Results from the NEXT prototypes

abstract:
  NEXT-100 is an electroluminescent high pressure Time Projection Chamber
currently under construction. It will search for the neutrino-less double beta
decay in 136Xe at the Canfranc Underground Laboratory. NEXT-100 aims to achieve
nearly intrinsic energy resolution and to highly suppress background events by
taking advantage of the unique properties of xenon in the gaseous phase as the
detection medium. In order to prove the principle of operation and to study
which are the best operational conditions, two prototypes were constructed:
NEXT-DEMO and NEXT-DBDM. In this paper we present the latest results from both
prototypes. We report the improvement in terms of light collection (?~3x?)
achieved by coating the walls of NEXT-DEMO with tetraphenyl butadiene (TPB),
the outstanding energy resolution of 1 % (Full Width Half Maximum) from
NEXT-DBDM as well as the tracking capabilities of this prototype (2.1 mm RMS
error for point-like depositions) achieved by using a square array of 8x8
SiPMs.


title:
A Constructive Method for Approximate Solution to Scalar Wiener-Hopf
  Equations

abstract:
  This paper presents a novel method of approximating the scalar Wiener-Hopf
equation; and therefore constructing an approximate solution. The advantages of
this method over the existing methods are reliability and explicit error
bounds. Additionally the degrees of the polynomials in the rational
approximation are considerably smaller than in other approaches.
  The need for a numerical solution is motivated by difficulties in computation
of the exact solution. The approximation developed in this paper is with a view
of generalisation to matrix Wiener-Hopf for which the exact solution, in
general, is not known.
  The first part of the paper develops error bounds in Lp for 1<p<\infty. These
indicate how accurately the solution is approximated in terms of how accurate
the equation is approximated.
  The second part of the paper describes the approach of approximately solving
the Wiener-Hopf equation that employs the Rational Caratheodory-Fejer
Approximation. The method is adapted by constructing a mapping of the real line
to the unit interval. Numerical examples to demonstrate the use of the proposed
technique are included (performed on Chebfun), yielding error as small as
10^{-12} on the whole real line.


title:
On Ihara's lemma for degree one and two cohomology over imaginary
  quadratic fields

abstract:
  We prove a version of Ihara's Lemma for degree q=1,2 cuspidal cohomology of
the symmetric space attached to automorphic forms of arbitrary weight (k\geq 2)
over an imaginary quadratic field with torsion (prime power) coefficients. This
extends an earlier result of the author which concerned the case k=2, q=1. Our
method here is different and uses results of Diamond and
Blasius-Franke-Grunewald. We discuss the relationship of our main theorem to
the problem of the existence of level-raising congruences.


title: Eigenvectors and eigenfunctionals of homogeneous order-preserving maps

abstract:
  This paper considers homogeneous order preserving continuous maps on the
normal cone of an ordered normed vector space. It is shown that certain
operators of that kind which are not necessarily compact themselves but have a
compact power have a positive eigenvector that is associated with the cone
spectral radius. We also derive conditions for the existence of homogeneous
order preserving eigenfunctionals. Our results are illustrated in a model for
spatially distributed two-sex populations.