title: Charge noise and spin noise in a semiconductor quantum device

abstract:
  Solid-state systems which mimic two-level atoms are being actively developed.
Improving the quantum coherence of these systems, for instance spin qubits or
single photon emitters using semiconductor quantum dots, involves dealing with
noise. The sources of noise are inherent to the semiconductor and are complex.
Charge noise results in a fluctuating electric field, spin noise in a
fluctuating magnetic field at the location of the qubit, and both can lead to
dephasing and decoherence of optical and spin states. We investigate noise in
an ultra-pure semiconductor using a minimally-invasive, ultra-sensitive, local
probe: resonance fluorescence from a single quantum dot. We distinguish between
charge noise and spin noise via a crucial difference in their optical
signatures. Noise spectra for both electric and magnetic fields are derived.
The noise spectrum of the charge noise can be fully described by the
fluctuations in an ensemble of localized charge defects in the semiconductor.
We demonstrate the "semiconductor vacuum" for the optical transition at
frequencies above 50 kHz: by operating the device at high enough frequencies,
we demonstrate transform-limited quantum dot optical linewidths.


title: On higher order Leibniz identities in TCFT

abstract:
  We extend the algebra of local observables in topological conformal field
theories by nonlocal operators. This allows to construct parameter-dependent
operations realized via certain integrals over the compactified moduli spaces,
satisfying analogues of the Leibniz and higher order Leibniz identities holding
up to homotopy. We conjecture that one can construct a complete set of such
operations which lead to a parameter-dependent version of Loday's homotopy
Leibniz algebras.


title:
Families of ultrafilters, and homomorphisms on infinite direct product
  algebras

abstract:
  Criteria are obtained for a filter F of subsets of a set I to be an
intersection of finitely many ultrafilters, respectively, finitely many
\kappa-complete ultrafilters for a given uncountable cardinal \kappa. From
these, general results are deduced concerning homomorphisms on infinite direct
product groups, which yield quick proofs of some results in the literature: the
{\L}o\'{s}-Eda theorem (characterizing homomorphisms from a
not-necessarily-countable direct product of modules to a slender module), and
some results of N. Nahlus and the author on homomorphisms on infinite direct
products of not-necessarily-associative k-algebras. The same tools allow other
results of Nahlus and the author to be nontrivially strengthened, and yield an
analog to one of their results, with nonabelian groups taking the place of
k-algebras.
  We briefly examine the question of how the common technique used in applying
the general results of this note to k-algebras on the one hand, and to
nonabelian groups on the other, might be extended to more general varieties of
algebras in the sense of universal algebra.
  In a final section, the Erd\H{o}s-Kaplansky Theorem on dimensions of vector
spaces D^I (D a division ring) is extended to reduced products D^I/F, and an
application is noted.


title: Dynamical properties of nanolasers based on few discrete emitters

abstract:
  We investigate the dynamical properties of nanolasers comprising a few
two-level emitters coupled to an optical cavity. A set of rate equations is
derived, which agree very well with a solution of the full master equation
model and makes it simple to investigate the properties of the system. Using a
linearized version of these rate equations, we can analytically express the
response of the nanolaser to a modulation of the pumping rate. These results
are compared to the modulation response obtained directly from the master
equation using a novel method. Using the rate equation method, we calculate the
modulation bandwidth and show that, contrary to conventional semiconductor
lasers, the nanolaser is typically over-damped and displays a dip in the
modulation bandwidth as the two-level systems become inverted. Both these
features can be traced back to the modeling of the emitters as two-level
systems that are incoherently pumped.


title: On error operators related to the arbitrary functions principle

abstract:
  The error on a real quantity Y due to the graduation of the measuring
instrument may be asymptotically represented, when the graduation is regular
and fines down, by a Dirichlet form on R whose square field operator does not
depend on the probability law of Y as soon as this law possesses a continuous
density. This feature is related to the "arbitrary functions principle"
(Poincar'e, Hopf). We give extensions of this property to Rd and to the Wiener
space for some approximations of the Brownian motion. This gives new
approximations of the Ornstein-Uhlenbeck gradient. These results apply to the
discretization of some stochastic differential equations encountered in
mechanics.


title: A Two Level Feedback System Design to Regulation Service Provision

abstract:
  Demand side management has gained increasing importance as the penetration of
renewable energy grows. Based on a Markov jump process modelling of a group of
thermostatic loads, this paper proposes a two level feedback system design
between the independent system operator (ISO) and the regulation service
provider such that two objectives are achieved: (1) the ISO can optimally
dispatch regulation signals to multiple providers in real time in order to
reduce the requirement for expensive spinning reserves, and (2) each regulation
provider can control its thermostatic loads to respond the ISO signal. It is
also shown that the amount of regulation service that can be provided is
implicitly restricted by a few fundamental parameters of the provider itself,
such as the allowable set point choice and its thermal constant. An interesting
finding is that the regulation provider's ability to provide a large amount of
long term accumulated regulation and short term signal tracking restrict each
other. Simulation results are presented to verify and illustrate the
performance of the proposed framework.


title: The lent particle method for marked point processes

abstract:
  Although introduced in the case of Poisson random measures, the lent particle
method applies as well in other situations. We study here the case of marked
point processes. In this case the Malliavin calculus (here in the sense of
Dirichlet forms) operates on the marks and the point process doesn't need to be
Poisson. The proof of the method is even much simpler than in the case of
Poisson random measures. We give applications to isotropic processes and to
processes whose jumps are modified by independent diffusions.


title:
Polarization of the Renyi Information Dimension with Applications to
  Compressed Sensing

abstract:
  In this paper, we show that the Hadamard matrix acts as an extractor over the
reals of the Renyi information dimension (RID), in an analogous way to how it
acts as an extractor of the discrete entropy over finite fields. More
precisely, we prove that the RID of an i.i.d. sequence of mixture random
variables polarizes to the extremal values of 0 and 1 (corresponding to
discrete and continuous distributions) when transformed by a Hadamard matrix.
Further, we prove that the polarization pattern of the RID admits a closed form
expression and follows exactly the Binary Erasure Channel (BEC) polarization
pattern in the discrete setting. We also extend the results from the single- to
the multi-terminal setting, obtaining a Slepian-Wolf counterpart of the RID
polarization. We discuss applications of the RID polarization to Compressed
Sensing of i.i.d. sources. In particular, we use the RID polarization to
construct a family of deterministic $\pm 1$-valued sensing matrices for
Compressed Sensing. We run numerical simulations to compare the performance of
the resulting matrices with that of random Gaussian and random Hadamard
matrices. The results indicate that the proposed matrices afford competitive
performances while being explicitly constructed.


title:
Iteration of the lent particle method for existence of smooth densities
  of Poisson functionals

abstract:
  In previous works we have introduced a new method called the lent particle
method which is an efficient tool to establish existence of densities for
Poisson functionals. We now go further and iterate this method in order to
prove smoothness of densities. More precisely, we construct Sobolev spaces of
any order and prove a Malliavin-type criterion of existence of smooth density.
We apply this approach to SDE's driven by Poisson random measures and also
present some non-trivial examples to which our method applies.


title:
Drichlet forms for Poisson measures and L\'evy processes : the lent
  particle method

abstract:
  We present a new approach to absolute continuity of laws of Poisson
functionals. The theoretical framework is that of local Dirichlet forms as a
tool to study probability spaces. The method gives rise to a new explicit
calculus that we show first on some simple examples : it consists in adding a
particle and taking it back after computing the gradient. Then we apply it to
SDE's driven by Poisson measure.


title:
La Notion D'irrationalit\'E Selon Un Math\'Ematicien Du Xe Si\`Ecle:
  Ab\=u Ja'far Al-Kh\={a}zin

abstract:
  The treatise of Ab\=u Ja'far al-Kh\=azin (Xth century), entitled "Commentary
on the introduction of the tenth book of the treatise of Euclid" ("tafs\={i}r
sadr al-maq\={a}la al-'\={a}shira min kit\={a}b Uql\={i}dis") exists in eight
manuscripts. In this paper we present a study of this treatise, based on a
first edition we have made, according to the copies of the manuscripts of
Paris, Leiden and Tunis, Ahmadiya. A reading of this treatise of al-Kh\={a}zin
proves that this mathematician did a profound study of the Xth book of Euclid
Elements, in order to gain a global comprehension. In effect, he presented a
condensed commentary, the originality of which can be felt both on the formal
and the contents levels. The aim of our study is to try, as much as possible,
to show this originality, referring specially to Pappus commentary of the "Xth
book", the works of R. Rashed on the history of algebra and a recent work of M.
Ben Miled on the Arabic commentaries of the Xth book. It appears to us that the
work of al-Kh\={a}zin concerning the Xth book, is situated in the current of an
Arabic tradition identified, mainly due to the works of R. Rashed, by: - an
algebraic representation of the geometrical work of Euclid, - a numerical
interpretation of the Euclidian notions, rendered possible by the introduction
of a unity for every kind of magnitude.


title:
Large and moderate deviation principles for recursive kernel density
  estimators defined by stochastic approximation method

abstract:
  In this paper we prove large and moderate deviations principles for the
recursive kernel estimators of a probability density function defined by the
stochastic approximation algorithm introduced by Mokkadem et al. [2009. The
stochastic approximation method for the estimation of a probability density. J.
Statist. Plann. Inference 139, 2459-2478]. We show that the estimator
constructed using the stepsize which minimize the variance of the class of the
recursive estimators defined in Mokkadem et al. (2009) gives the same pointwise
LDP and MDP as the Rosenblatt kernel estimator. We provide results both for the
pointwise and the uniform deviations.


title:
Precoded Integer-Forcing Universally Achieves the MIMO Capacity to
  Within a Constant Gap

abstract:
  An open-loop single-user multiple-input multiple-output communication scheme
is considered where a transmitter, equipped with multiple antennas, encodes the
data into independent streams all taken from the same linear code. The coded
streams are then linearly precoded using the encoding matrix of a perfect
linear dispersion space-time code. At the receiver side, integer-forcing
equalization is applied, followed by standard single-stream decoding. It is
shown that this communication architecture achieves the capacity of any
Gaussian multiple-input multiple-output channel up to a gap that depends only
on the number of transmit antennas.


title: Simple random walk on distance-regular graphs

abstract:
  A survey is presented of known results concerning simple random walk on the
class of distance-regular graphs. One of the highlights is that electric
resistance and hitting times between points can be explicitly calculated and
given strong bounds for, which leads in turn to bounds on cover times, mixing
times, etc. Also discussed are harmonic functions, moments of hitting and cover
times, the Green's function, and the cutoff phenomenon. The main goal of the
paper is to present these graphs as a natural setting in which to study simple
random walk, and to stimulate further research in the field.


title: Iteration of Involutes of Constant Width Curves in the Minkowski Plane

abstract:
  In this paper we study properties of the area evolute (AE) and the center
symmetry set (CSS) of a convex planar curve $\gamma$. The main tool is to
define a Minkowski plane where $\gamma$ becomes a constant width curve. In this
Minkowski plane, the CSS is the evolute of $\gamma$ and the AE is an involute
of the CSS. We prove that the AE is contained in the region bounded by the CSS
and has smaller signed area.
  The iteration of involutes generate a pair of sequences of constant width
curves with respect to the Minkowski metric and its dual, respectively. We
prove that these sequences are converging to symmetric curves with the same
center, which can be regarded as a central point of the curve $\gamma$.


title:
Angular-dependent upper critical field of overdoped
  Ba(Fe$_{1-x}$Ni$_x$)$_2$As$_2$

abstract:
  In-plane resistivity measurements as a function of temperature, magnetic
field and its orientation with respect to the crystallographic $ab-$plane were
used to study the upper critical field, $H_{c2}$, of two overdoped compositions
of the iron-based superconductor Ba(Fe$_{1-x}$Ni$_x$)$_2$As$_2$, $x=$0.054 and
$x$=0.072. Measurements were performed using precise alignment (with accuracy
less than 0.1$^o$) of magnetic field with respect to the Fe-As-plane. The
dependence of the $H_{c2}$ on angle $\theta$ between the field and the
$ab$-plane was measured in isothermal conditions in a broad temperature range.
We found that the shape of $H_{c2}(\theta)$, clearly deviates from
Ginzburg-Landau functional form.


title:
Scalar Quantize-and-Forward for Symmetric Half-duplex Two-Way Relay
  Channels

abstract:
  Scalar Quantize & Forward (QF) schemes are studied for the Two-Way Relay
Channel. Different QF approaches are compared in terms of rates as well as
relay and decoder complexity. A coding scheme not requiring Slepian-Wolf coding
at the relay is proposed and properties of the corresponding sum-rate
optimization problem are presented. A numerical scheme similar to the
Blahut-Arimoto algorithm is derived that guides optimized quantizer design. The
results are supported by simulations.


title: Variable-Length Channel Quantizers for Maximum Diversity and Array Gains

abstract:
  We consider a $t \times 1$ multiple-antenna fading channel with quantized
channel state information at the transmitter (CSIT). Our goal is to maximize
the diversity and array gains that are associated with the symbol error rate
(SER) performance of the system. It is well-known that for both beamforming and
precoding strategies, finite-rate fixed-length quantizers (FLQs) cannot achieve
the full-CSIT diversity and array gains. In this work, for any function
$f(P)\in\omega(1)$, we construct variable-length quantizers (VLQs) that can
achieve these full-CSIT gains with rates $1+(f(P) \log P)/P$ and $1+f(P)/P^t$
for the beamforming and precoding strategies, respectively, where $P$ is the
power constraint of the transmitter. We also show that these rates are the best
possible up to $o(1)$ multipliers in their $P$-dependent terms. In particular,
although the full-CSIT SER is not achievable at any (even infinite) feedback
rate, the full-CSIT diversity and array gains can be achieved with a feedback
rate of 1 bit per channel state asymptotically.


title:
Nucleon-Meson Couplings in One Boson Exchange Potential using
  Non-Critical String Theory

abstract:
  A non-critical holographic QCD model constructed in the six dimensional
Anti-de-Sitter ($AdS_6$) supergravity background is employed to study a the
baryon. It is shown that the size of the baryon is of order one with respect to
the $\lambda$, however, it is smaller than the scale of the dual QCD. An
effective four dimensional action for the nucleon is obtained in terms of the
meson exchange potentials. All meson-nucleon couplings in the non-critical
$AdS_6$ background are calculated. Results obtained using our model are
compared with predictions of four modern phenomenological interaction models.
Also, our numerical results are compared with the results of the Sakai-Sugimoto
(SS) model which indicate that the non-critical holographic QCD model can be a
good toy to calculate the meson-nucleon couplings.


title: Achieving Fully Proportional Representation is Easy in Practice

abstract:
  We provide experimental evaluation of a number of known and new algorithms
for approximate computation of Monroe's and Chamberlin-Courant's rules. Our
experiments, conducted both on real-life preference-aggregation data and on
synthetic data, show that even very simple and fast algorithms can in many
cases find near-perfect solutions. Our results confirm and complement very
recent theoretical analysis of Skowron et al., who have shown good lower bounds
on the quality of (some of) the algorithms that we study.


title:
The Drude weight of the spin-1/2 XXZ chain: density matrix
  renormalization group versus exact diagonalization

abstract:
  We revisit the problem of the spin Drude weight D of the integrable spin-1/2
XXZ chain using two complementrary approaches, exact diagonalization (ED) and
the time-dependent density-matrix renormalization group (tDMRG). We pursue two
main goals. First, we present extensive results for the temperature dependence
of D. By exploiting time translation invariance within tDMRG, one can extract D
for significantly lower temperatures than in previous tDMRG studies. Second, we
discuss the numerical quality of the tDMRG data and elaborate on details of the
finite-size scaling of the ED results, comparing calculations carried out in
the canonical and grand-canonical ensembles. Furthermore, we analyze the
behavior of the Drude weight as the point with SU(2)-symmetric exchange is
approached and discuss the relative contribution of the Drude weight to the sum
rule as a function of temperature.


title: Hyperfine structure of the $2^3S-$state in the ${}^9$Be atom

abstract:
  A number of bound states properties and the hyperfine structure of the
23S(L=0)-state in the Be atom are determined from the results of highly
accurate computations. The energies of the hyperfine structure levels for this
state are {\epsilon}(F=12) = -13725.635(7) MHz, {\epsilon}(F=32) = -5490.254(7)
MHz and {\epsilon}(F=52) = 8235.381(7) MHz, respectively. The hyperfine
structure splittings are {\Delta}12 = 8235.381(7) MHz and {\Delta}23 =
13725.635(7) MHz, respectively. The spectrum of low-lying (bound) triplet
states in the Be atom is briefly investigated.


title:
Measurement of the proton light response of various LAB based
  scintillators and its implication for supernova neutrino detection via
  neutrino-proton scattering

abstract:
  The proton light output function in electron-equivalent energy of various
scintillators based on linear alkylbenzene (LAB) has been measured in the
energy range from 1 MeV to 17.15 MeV for the first time. The measurement was
performed at the Physikalisch-Technische Bundesanstalt (PTB) using a neutron
beam with continuous energy distribution. The proton light output data is
extracted from proton recoil spectra originating from neutron-proton scattering
in the scintillator. The functional behavior of the proton light output is
described succesfully by Birks' law with a Birks constant kB between (0.0094
+/- 0.0002) cm/MeV and (0.0098 +/- 0.0003) cm/MeV for the different LAB
solutions. The constant C, parameterizing the quadratic term in the generalized
Birks law, is consistent with zero for all investigated scintillators with an
upper limit (95% CL) of about 10^{-7} cm^2/MeV^2. The resulting quenching
factors are especially important for future planned supernova neutrino
detection based on the elastic scattering of neutrinos on protons. The impact
of proton quenching on the supernova event yield from neutrino-proton
scattering is discussed.

categories: astro-ph.IM hep-ex hep-ph nucl-ex physics.ins-det


title: Nonlinear graphene plasmonics: amplitude equation

abstract:
  Using perturbation expansion of Maxwell equations, the amplitude equation is
derived for nonlinear TM and TE surface plasmon waves supported by graphene.
The equation describes interplay between in-plane beam diffraction and
nonlinerity due to light intensity induced corrections to graphene conductivity
and susceptibility of dielectrics. For strongly localized TM plasmons, graphene
is found to bring the superior contribution to the overall nonlinearity. In
contrast, nonlinear response of the substrate and cladding dielectrics can
become dominant for weakly localized TE plasmons.


title: Propagation of ultra-short solitons in stochastic Maxwell's equations

abstract:
  We study the propagation of ultra-short short solitons in a cubic nonlinear
medium modeled by nonlinear Maxwell's equations with stochastic variations of
media. We consider three cases: variations of (a) the dispersion, (b) the phase
velocity, (c) the nonlinear coefficient. Using a modified multi-scale expansion
for stochastic systems, we derive new stochastic generalizations of the short
pulse equation that approximate the solutions of stochastic nonlinear Maxwell's
equations. Numerical simulations show that soliton solutions of the short pulse
equation propagate stably in stochastic nonlinear Maxwell's equations and that
the generalized stochastic short pulse equations approximate the solutions to
the stochastic Maxwell's equations over the distances under consideration. This
holds for both a pathwise comparison of the stochastic equations as well as for
a comparison of the resulting probability densities.


title:
Joint Power Adjustment and Interference Mitigation Techniques for
  Cooperative Spread Spectrum Systems

abstract:
  This paper presents joint power allocation and interference mitigation
techniques for the downlink of spread spectrum systems which employ multiple
relays and the amplify and forward cooperation strategy. We propose a joint
constrained optimization framework that considers the allocation of power
levels across the relays subject to an individual power constraint and the
design of linear receivers for interference suppression. We derive constrained
minimum mean-squared error (MMSE) expressions for the parameter vectors that
determine the optimal power levels across the relays and the linear receivers.
In order to solve the proposed optimization problem efficiently, we develop
joint adaptive power allocation and interference suppression algorithms that
can be implemented in a distributed fashion. The proposed stochastic gradient
(SG) and recursive least squares (RLS) algorithms mitigate the interference by
adjusting the power levels across the relays and estimating the parameters of
the linear receiver. SG and RLS channel estimation algorithms are also derived
to determine the coefficients of the channels across the base station, the
relays and the destination terminal. The results of simulations show that the
proposed techniques obtain significant gains in performance and capacity over
non-cooperative systems and cooperative schemes with equal power allocation.


title: Three-manifold invariant from functional integration

abstract:
  We give a precise definition and produce a path-integral computation of the
normalized partition function of the abelian U(1) Chern-Simons field theory
defined in a general closed oriented 3-manifold. We use the Deligne-Beilinson
formalism, we sum over the inequivalent U(1) principal bundles over the
manifold and, for each bundle, we integrate over the gauge orbits of the
associated connection 1- forms. The result of the functional integration is
compared with the abelian U(1) Reshetikhin-Turaev surgery invariant.


title:
A Universal Probability Assignment for Prediction of Individual
  Sequences

abstract:
  Is it a good idea to use the frequency of events in the past, as a guide to
their frequency in the future (as we all do anyway)? In this paper the question
is attacked from the perspective of universal prediction of individual
sequences. It is shown that there is a universal sequential probability
assignment, such that for a large class loss functions (optimization goals),
the predictor minimizing the expected loss under this probability, is a good
universal predictor. The proposed probability assignment is based on randomly
dithering the empirical frequencies of states in the past, and it is easy to
show that randomization is essential. This yields a very simple universal
prediction scheme which is similar to Follow-the-Perturbed-Leader (FPL) and
works for a large class of loss functions, as well as a partial justification
for using probabilistic assumptions.


title:
A strategy-based proof of the existence of the value in zero-sum
  differential games

abstract:
  The value of a zero-sum differential games is known to exist, under Isaacs'
condition, as the unique viscosity solution of a Hamilton-Jacobi-Bellman
equation. In this note we provide a self-contained proof based on the
construction of $\ep$-optimal strategies, which is inspired by the "extremal
aiming" method from Krasovskii and Subbotin.


title: Linear Programming Decoding of Spatially Coupled Codes

abstract:
  For a given family of spatially coupled codes, we prove that the LP threshold
on the BSC of the graph cover ensemble is the same as the LP threshold on the
BSC of the derived spatially coupled ensemble. This result is in contrast with
the fact that the BP threshold of the derived spatially coupled ensemble is
believed to be larger than the BP threshold of the graph cover ensemble as
noted by the work of Kudekar et al. (2011, 2012). To prove this, we establish
some properties related to the dual witness for LP decoding which was
introduced by Feldman et al. (2007) and simplified by Daskalakis et al. (2008).
More precisely, we prove that the existence of a dual witness which was
previously known to be sufficient for LP decoding success is also necessary and
is equivalent to the existence of certain acyclic hyperflows. We also derive a
sublinear (in the block length) upper bound on the weight of any edge in such
hyperflows, both for regular LPDC codes and for spatially coupled codes and we
prove that the bound is asymptotically tight for regular LDPC codes. Moreover,
we show how to trade crossover probability for "LP excess" on all the variable
nodes, for any binary linear code.


title: A joint analysis of the Drake equation and the Fermi paradox

abstract:
  I propose a unified framework for a joint analysis of the Drake equation and
the Fermi paradox, which enables a simultaneous, quantitative study of both of
them. The analysis is based on a simplified form of the Drake equation and on a
fairly simple scheme for the colonization of the Milky Way. It appears that for
sufficiently long-lived civilizations, colonization of the Galaxy is the only
reasonable option to gain knowledge about other life forms. This argument
allows one to define a region in the parameter space of the Drake equation
where the Fermi paradox definitely holds (Strong Fermi paradox).


title:
Random Access and Source-Channel Coding Error Exponents for Multiple
  Access Channels

abstract:
  A new universal coding/decoding scheme for random access with collision
detection is given in the case of two senders. The result is used to give an
achievable joint source-channel coding error exponent for multiple access
channels in the case of independent sources. This exponent is improved in a
modified model that admits error free 0 rate communication between the senders.


title: Maximum likelihood estimation for small noise multiscale diffusions

abstract:
  We study the problem of parameter estimation for stochastic differential
equations with small noise and fast oscillating parameters. Depending on how
fast the intensity of the noise goes to zero relative to the homogenization
parameter, we consider three different regimes. For each regime, we construct
the maximum likelihood estimator and we study its consistency and asymptotic
normality properties. A simulation study for the first order Langevin equation
with a two scale potential is also provided.


title:
The Murchison Widefield Array: solar science with the low frequency SKA
  Precursor

abstract:
  The Murchison Widefield Array is a low frequency (80 - 300 MHz) SKA
Precursor, comprising 128 aperture array elements (known as tiles) distributed
over an area of 3 km diameter. The MWA is located at the extraordinarily radio
quiet Murchison Radioastronomy Observatory in the mid-west of Western
Australia, the selected home for the Phase 1 and Phase 2 SKA low frequency
arrays. The MWA science goals include: 1) detection of fluctuations in the
brightness temperature of the diffuse redshifted 21 cm line of neutral hydrogen
from the epoch of reionisation; 2) studies of Galactic and extragalactic
processes based on deep, confusion-limited surveys of the full sky visible to
the array; 3) time domain astrophysics through exploration of the variable
radio sky; and 4) solar imaging and characterisation of the heliosphere and
ionosphere via propagation effects on background radio source emission. This
paper concentrates on the capabilities of the MWA for solar science and
summarises some of the solar science results to date, in advance of the initial
operation of the final instrument in 2013.


title: A primer on reflexivity and price dynamics under systemic risk

abstract:
  A simple quantitative example of a reflexive feedback process and the
resulting price dynamics after an exogenous price shock to a financial network
is presented. Furthermore, an outline of a theory that connects financial
reflexivity, which stems from cross-ownership and delayed or incomplete
information, and no-arbitrage pricing theory under systemic risk is provided.


title: New Galactic supernova remnants discovered with IPHAS

abstract:
  As part of a systematic search programme of a 10-degree wide strip of the
Northern Galactic plane we present preliminary evidence for the discovery of
four (and possibly five) new supernova remnants (SNRs). The pilot search area
covered the 19-20 hour right ascension zone sampling from +20 to +55 degrees in
declination using binned mosaic images from the INT Photometric H-alpha Survey
(IPHAS). The optical identification of the candidate SNRs was based mainly on
their filamentary and arc-like emission morphologies, their apparently
coherent, even if fractured structure and clear disconnection from any diffuse
neighbouring HII region type nebulosity. Follow-up optical spectroscopy was
undertaken, sampling carefully across prominent features of these faint
sources. The resulting spectra revealed typical emission line ratios for shock
excited nebulae which are characteristic of SNRs, which, along with the latest
diagnostic diagrams, strongly support the likely SNR nature of these sources:
G038.7-1.3 (IPHASX J190640.5+042819); G067.6+0.9 (IPHASX J195744.9+305306);
G066.0-0.0 (IPHASX J195749.2+290259) and G065.8-0.5 (IPHASX J195920.4+283740).
A fifth possible younger, higher density nebula SNR candidate, G067.8+0.5
(IPHASX J200002.4+305035) was discovered about 5 arcmins to the west of IPHASX
J195744.9+305306, and warrants further study. A multi-wavelength cross-check
from available archived data in the regions of these candidates was also
performed with a focus on possible radio counterparts.


title:
Vlasov versus reduced kinetic theories for helically symmetric
  equilibria

abstract:
  A new constant of motion for helically symmetric equilibria in the vicinity
of the magnetic axis is obtained in the framework of Vlasov theory. In view of
this constant of motion the Vlasov theory is compared with drift kinetic and
gyrokinetic theories near axis. It turns out that as in the case of
axisymmetric equilibria [H. Tasso and G. N. Throumoulopoulos, Phys. Plasmas 18,
064507 (2011)] the Vlasov current density thereon can differ appreciably from
the drift kinetic and gyrokinetic current densities. This indicates some
limitation on the implications of reduced kinetic theories, in particular as
concerns the physics of energetic particles in the central region of
magnetically confined plasmas.


title:
Examining the meaning of the peptide transfer free energy obtained from
  blocked (Gly)_n and cyclic-diglycine model compounds

abstract:
  In experiments, the free energy of transferring the peptide group from water
to an osmolyte solution is obtained using the transfer free energy of (Gly)_n
with the added assumption that a constant incremental change in free energy
with n implies that each additional unit makes an independent contribution to
the free energy. Here we test this assumption and uncover its limitations.
Together with results for cyclic-diglycine, we show that, in principle, it is
not possible to obtain a peptide group transfer free energy that is independent
of the model system. We calculate the hydration free energy of
acetyl-(Gly)_n-methyl amide (n=1..7) peptides modeled in the extended
conformation in water and osmolyte solutions and find that the hydration free
energy is linear in n, suggestive of independent, additive group-contributions.
To probe the observed linearity further, we study the hydration of the solute
bereft of water molecules in the first hydration shell. This conditioned solute
arises naturally in the theoretical formulation and helps us focus on hydration
effects uncluttered by the complexities of short-range solute-water
interactions. We subdivide the conditioned solute into n+1 peptide groups and a
methyl end group. The binding energy of each of these groups with the solvent
is Gaussian distributed, but the near neighbor binding energies are themselves
correlated: the (i,i+1) correlation is the strongest and tends to lower the
free energy over the independent group case. We show that the observed
linearity can be explained by the similarity of near neighbor correlations.
Implications for group additive transfer free energy models are indicated.


title: On subgroups of finite index in branch groups

abstract:
  We give a structural description of the normal subgroups of subgroups of
finite index in branch groups in terms of rigid stabilizers. This gives further
insight into the structure lattices of branch groups introduced by the second
author. We derive a condition concerning abstract commensurability of branch
groups acting on the p-ary tree for any prime p.


title: Multiple Vortices for the Shallow Water Equation

abstract:
  In this paper, we construct stationary classical solutions of the shallow
water equation with vanishing Froude number $Fr$ in the so-called lake model.
  To this end we need to study solutions to the following semilinear elliptic
problem \[{cases} -\varepsilon^2\text{div}(\frac{\nabla
u}{b})=b(u-q\log\frac{1}{\varepsilon})_+^{p},& \text{in}\; \Omega, u=0,
&\text{on}\;\partial \Omega, {cases} \] for small $\varepsilon>0$, where $p>1$,
$\text{div}(\frac{\nabla q}{b})=0$ and $\Omega\subset\mathbb{R}^2$ is a smooth
bounded domain,.
  We showed that if $\frac{q^2}{b}$ has $m$ strictly local minimum(maximum)
points $\bar z_i,\,i=1,...,m$, then there is a stationary classical solution
approximating stationary $m$ points vortex solution of shallow water equations
with vorticity $\sum_{i=1}^m\frac{2\pi q(\bar z_i)}{b(\bar z_i)}$. Moreover,
strictly local minimum points of $\frac{q^2}{b}$ on the boundary can also give
vortex solutions for the shallow water equation. As a further study we
construct vortex pair solutions as well.
  Existence and asymptotic behavior of single point non-vanishing vortex
solutions were studied by S. De Valeriola and J. Van Schaftingen.


title: Dilepton + jet signature of Split-UED at the LHC

abstract:
  We study the signature of dilepton and a hard jet ($\ell^+\ell^-j$) via heavy
new gauge boson production in split universal extra dimension scenario where
the Kaluza-Klein parity is conserved but the Kaluza-Klein number is not. A hard
cut to the jet energy effectively removes virtually all possible backgrounds
and provides a handle to search of new physics involving new neutral heavy
states as the Kaluza-Klein $Z$ boson. The signature can be more generically
used in search of other new states such as graviton and radion in warped extra
dimension models.


title:
On Connectivity Thresholds in the Intersection of Random Key Graphs on
  Random Geometric Graphs

abstract:
  In a random key graph (RKG) of $n$ nodes each node is randomly assigned a key
ring of $K_n$ cryptographic keys from a pool of $P_n$ keys. Two nodes can
communicate directly if they have at least one common key in their key rings.
We assume that the $n$ nodes are distributed uniformly in $[0,1]^2.$ In
addition to the common key requirement, we require two nodes to also be within
$r_n$ of each other to be able to have a direct edge. Thus we have a random
graph in which the RKG is superposed on the familiar random geometric graph
(RGG). For such a random graph, we obtain tight bounds on the relation between
$K_n,$ $P_n$ and $r_n$ for the graph to be asymptotically almost surely
connected.


title:
Validity of the time-dependent variational approximation to the Gaussian
  wavepacket method applied to double-well systems

abstract:
  We have examined the validity of the time-dependent variational approximation
(TDVA) to the Gaussian wavepacket method (GWM) for quantum double-well (DW)
systems, by using the quasi-exact spectral method (SM). Comparisons between
results of wavefunctions, averages of position and momentum, the
auto-correlation function, and an uncertainty product calculated by SM and TDVA
have been made. It has been shown that a given initial Gaussian wavepacket in
SM is quickly deformed at $t > 0$ where a wavepacket cannot be expressed by a
{\it single} Gaussian, and that assumptions on averages of higher-order
fluctuations in TDVA are not justified. These results cast some doubt on an
application of TDVA to DW systems. Gaussian wavepacket dynamics in anharmonic
potential systems is studied also.


title: Constructing Skolem sequences via generating trees

abstract:
  A Skolem sequence is a linear arrangement of the multiset, {1, 1, 2, 2, ...,
n, n} such that if r in [n] appears in positions i and j, then |i-j| = r. We
first translate the problem to a particular set of perfect matchings, then
apply the method of generating trees for open arc diagrams to generate
exhaustively all Skolem sequences of a given size. Tracking the arc length
between pairs of vertices in an arc annotated diagram is the central task.
Although we do not surpass previously known enumerative results, this method
drastically reduces the search space compared to previously known methods.


title:
An integral representation, some inequalities, and complete monotonicity
  of Bernoulli numbers of the second kind

abstract:
  In the paper, the authors discover an integral representation, some
inequalities, and complete monotonicity of Bernoulli numbers of the second
kind.


title: Joint Design of Channel and Network Coding for Star Networks

abstract:
  Channel coding alone is not sufficient to reliably transmit a message of
finite length $K$ from a source to one or more destinations as in, e.g., file
transfer. To ensure that no data is lost, it must be combined with rateless
erasure correcting schemes on a higher layer, such as a time-division multiple
access (TDMA) system paired with automatic repeat request (ARQ) or random
linear network coding (RLNC). We consider binary channel coding on a binary
symmetric channel (BSC) and q-ary RLNC for erasure correction in a star
network, where Y sources send messages to each other with the help of a central
relay. In this scenario RLNC has been shown to have a throughput advantage over
TDMA schemes as K and q tend to infinity. In this paper we focus on finite
block lengths and compare the expected throughputs of RLNC and TDMA. For a
total message length of K bits, which can be subdivided into blocks of smaller
size prior to channel coding, we obtain the channel coding rate and the number
of blocks that maximize the expected throughput of both RLNC and TDMA, and we
find that TDMA is more throughput-efficient for small message lengths K and
small q.


title:
Fundamental Inequalities and Identities Involving Mutual and Directed
  Informations in Closed-Loop Systems

abstract:
  We present several novel identities and inequalities relating the mutual
information and the directed information in systems with feedback. The internal
blocks within such systems are restricted only to be causal mappings, but are
allowed to be non-linear, stochastic and time varying. Moreover, the involved
signals can be arbitrarily distributed. We bound the directed information
between signals inside the feedback loop by the mutual information between
signals inside and outside the feedback loop. This fundamental result has an
interesting interpretation as a law of conservation of information flow.
Building upon it, we derive several novel identities and inequalities, which
allow us to prove some existing information inequalities under less restrictive
assumptions. Finally, we establish new relationships between nested directed
informations inside a feedback loop. This yields a new and general
data-processing inequality for systems with feedback.


title: Engineering Small Space Dictionary Matching

abstract:
  The dictionary matching problem is to locate occurrences of any pattern among
a set of patterns in a given text. Massive data sets abound and at the same
time, there are many settings in which working space is extremely limited. We
introduce dictionary matching software for the space-constrained environment
whose running time is close to linear. We use the compressed suffix tree as the
underlying data structure of our algorithm, thus, the working space of our
algorithm is proportional to the optimal compression of the dictionary. We also
contribute a succinct tool for performing constant-time lowest marked ancestor
queries on a tree that is succinctly encoded as a sequence of balanced
parentheses, with linear time preprocessing of the tree. This tool should be
useful in many other applications. Our source code is available at
http://www.sci.brooklyn.cuny.edu/~sokol/dictmatch.html


title:
An Asteroid Belt Interpretation for the Timing Variations of the
  Millisecond Pulsar B1937+21

abstract:
  Pulsar timing observations have revealed companions to neutron stars that
include other neutron stars, white dwarfs, main-sequence stars, and planets. We
demonstrate that the correlated and apparently stochastic residual times of
arrival from the millisecond pulsar B1937+21 are consistent with the signature
of an asteroid belt having a total mass less than approximately 0.05 Earth
masses. Unlike the solar system's asteroid belt, the best fit pulsar asteroid
belt extends over a wide range of radii, consistent with the absence of any
shepherding companions. We suggest that any pulsar that has undergone
accretion-driven spin-up and subsequently evaporated its companion may harbor
orbiting asteroid mass objects. The resulting timing variations may
fundamentally limit the timing precision of some of the other millisecond
pulsars. Observational tests of the asteroid belt model include identifying
periodicities from individual asteroids, which are difficult; testing for
statistical stationarity that become possible when observations are conducted
over a longer observing span; and searching for reflected radio emission.


title:
Some Bernstein functions and integral representations concerning
  harmonic and geometric means

abstract:
  It is general knowledge that the harmonic mean
$H(x,y)=\frac2{\frac1x+\frac1y}$ and that the geometric mean
$G(x,y)=\sqrt{xy}\,$, where $x$ and $y$ are two positive numbers. In the paper,
the authors show by several approaches that the harmonic mean
$H_{x,y}(t)=H(x+t,y+t)$ and the geometric mean $G_{x,y}(t)=G(x+t,y+t)$ are all
Bernstein functions of $t\in(-\min\{x,y\},\infty)$ and establish integral
representations of the means $H_{x,y}(t)$ and $G_{x,y}(t)$.


title: Automatic Verification of Parameterised Interleaved Multi-Agent Systems

abstract:
  A key problem in verification of multi-agent systems by model checking
concerns the fact that the state-space of the system grows exponentially with
the number of agents present. This makes practical model checking unfeasible
whenever the system contains more than a few agents. In this paper we put
forward a technique to establish a cutoff result, thereby showing that all
systems of arbitrary number of agents can be verified by model checking a
single system containing a number of agents equal to the cutoff of the system.
While this problem is undecidable in general, we here define a class of
parameterised interpreted systems and a parameterised temporal-epistemic logic
for which the result can be shown. We exemplify the theoretical results on a
robotic example and present an implementation of the technique on top of mcmas,
an open-source model checker for multi-agent systems.


title:
A new proof of the geometric-arithmetic mean inequality by Cauchy's
  integral formula

abstract:
  Let $a=(a_1,a_2,...c,a_n)$ for $n\in\mathbb{N}$ be a given sequence of
positive numbers. In the paper, the authors establish, by using Cauchy's
integral formula in the theory of complex functions, an integral representation
of the principal branch of the geometric mean {equation*}
G_n(a+z)=\Biggl[\prod_{k=1}^n(a_k+z)\Biggr]^{1/n} {equation*} for
$z\in\mathbb{C}\setminus(-\infty,-\min\{a_k,1\le k\le n\}]$, and then provide a
new proof of the well known GA mean inequality.


title:
Delay Minimization in Varying-Bandwidth Direct Multicast with Side
  Information

abstract:
  We study the delay minimization in a direct multicast communication scheme
where a base station wishes to transmit a set of original packets to a group of
clients. Each of the clients already has in its cache a subset of the original
packets, and requests for all the remaining packets. The base station
communicates directly with the clients by broadcasting information to them.
Assume that bandwidths vary between the station and different clients. We
propose a method to minimize the total delay required for the base station to
satisfy requests from all clients.


title:
Segmented Vortex Telescope and its Tolerance to Diffraction Effects and
  Primary Aberrations

abstract:
  We propose the segmented Large Millimeter Telescope (LMT/GTM),as the largest
spatial light modulator capable of producing vortex beams of integer
topological charge. This observing mode could be applied for direct exoplanet
searches in the millimeter or submillimeter regimes. We studied the stability
of the vortex structure against aberrations and diffraction effects inherent to
the size and segmented nature of the collector mirror. In the presence of low
order aberrations the focal distribution of the system remains stable. Our
results show that these effects depend on the topological charge of the vortex
and the relative orientation of the aberration with respect to the antenna
axis. Coma and defocus show no large effects in the image at the focal plane,
nevertheless the system is very sensitive to astigmatism. Heat turbulence,
simulated by random aberrations, shows that the system behaves in a similar way
as astigmatism dissociating the vortices. We propose the Segmented Vortex
Telescope as a novel approach for the detection of giant planets outside
circumstellar disks around nearby stars. Since our results are applicable to
other facilities with segmented surfaces, we suggest that this idea should be
considered as a regular observation mode complementary to interferometric
methods.


title:
Shaping the relation between the mass of supermassive black holes and
  the velocity dispersion of galactic bulges

abstract:
  I use the fact that the radiation emitted by the accretion disk of
supermassive black hole can heat up the surrounding gas in the protogalaxy to
achieve hydrostatic equilibrium during the galaxy formation. The correlation
between the black hole mass M_BH and velocity dispersion \sigma thus naturally
arises. The result generally agrees with empirical fittings from observational
data, even with M_BH \leq 10^6M_sun. This model provides a clear picture on how
the properties of the galactic supermassive black holes are connected with the
kinetic properties of the galactic bulges.


title:
Coexistence of the Pseudogap and the Superconducting Gap Revealed by the
  \textit{c}-axis Optical Study of
  YBa$_{2}$(Cu$_{1-x}$Zn$_{x}$)$_{3}$O$_{7-\delta}$

abstract:
  To address the issue of the pseudogap in the superconducting state of the
high temperature superconducting cuprates, we studied the temperature dependent
redistribution of the spectral weight in the \textit{c}-axis polarized optical
spectra for underdoped YBa$_{2}$(Cu$_{1-x}$Zn$_{x}$)$_{3}$O$_{7-\delta}$ single
crystals with $x=0,0.007,$ 0.012, and 0.04. It was found that for Zn
substituted samples, the spectral weight transfer to the high energy region,
which characterizes the pseudogap state, continues even below the
superconducting transition temperature (\textit{T}$_{c}$), indicating the
coexistence of the pseudogap and the superconducting gap. Moreover, the
observation of the pseudogap in the Zn-doped non-superconducting sample gives
evidence that the pseudogap is not a precursor of superconductivity.


title: Pair Production of a 125 GeV Higgs Boson in MSSM and NMSSM at the LHC

abstract:
  In light of the recent LHC Higgs search data, we investigate the pair
production of a SM-like Higgs boson around 125 GeV in the MSSM and NMSSM. We
first scan the parameter space of each model by considering various
experimental constraints, and then calculate the Higgs pair production rate in
the allowed parameter space. We find that in most cases the dominant
contribution to the Higgs pair production comes from the gluon fusion process
and the production rate can be greatly enhanced, maximally 10 times larger than
the SM prediction (even for a TeV-scale stop the production rate can still be
enhanced by a factor of 1.3). We also calculate the chi-square value with the
current Higgs data and find that in the most favored parameter region the
production rate is enhanced by a factor of 1.45 in the MSSM, while in the NMSSM
the production rate can be enhanced or suppressed (\sigma_{SUSY}/\sigma_{SM}
varies from 0.7 to 2.4).


title: Affine Near-Semirings over Brandt Semigroups

abstract:
  In order to study the structure of $A^+(B_n)$ -- the affine near-semiring
over a Brandt semigroup -- this work completely characterizes the Green's
classes of its semigroup reducts. In this connection, this work characterizes
the elements of $A^+(B_n)$ and reports the size of $A^+(B_n)$. Further,
idempotents and regular elements of the semigroup reducts of $A^+(B_n)$ have
also been characterized and studied some relevant semigroups in $A^+(B_n)$.


title:
Theory of Network Contractor Dynamics for Exploring Thermodynamic
  Properties of Two-dimensional Quantum Lattice Models

abstract:
  Based on the tensor network state representation, we develop a nonlinear
dynamic theory coined as network contractor dynamics (NCD) to explore the
thermodynamic properties of two-dimensional quantum lattice models. By invoking
the rank-$1$ decomposition in the multi-linear algebra, the NCD scheme makes
the contraction of the tensor network of the partition function be realized
through a contraction of a local tensor cluster with vectors on its boundary.
An imaginary-time-sweep algorithm for implementation of the NCD method is
proposed for practical numerical simulations. We benchmark the NCD scheme on
the square Ising model, which shows a great accuracy. Besides, the results on
the spin-1/2 Heisenberg antiferromagnet on honeycomb lattice are disclosed in
good agreement with the quantum Monte Carlo calculations. The
quasi-entanglement entropy $S$, Lyapunov exponent $I^{lya}$ and loop character
$I^{loop}$ are introduced within the dynamic scheme, which are found to display
the ``nonlocality" near the critical point, and can be applied to determine the
thermodynamic phase transitions of both classical and quantum systems.


title: The Preon Sector of the SLq(2) (Knot) Model

abstract:
  We describe a Lagrangian defining the preon sector of the knot model. The
preons are the elements of the fundamental representation of SLq(2), and
unexpectedly agree with the preons conjectured by Harari and by Shupe. The
leptons, neutrinos, up and down quarks, described as $j=3/2$ representations,
and the electroweak vectors, described as $j=3$ representations, of SLq(2) also
have the preon composition required by the schemes of Harari and of Shupe. The
coupling constants and masses required by the preon Lagrangian introduce form
factors that are simple functions of the knot model parameters. As previously
shown the knot model has similarly provided a possible parametrization of the
masses and electroweak coupling constants (Kobayashi-Maskawa matrix) of the
standard model. There is an alternative formulation of the kinematics
permitting possible additional isotopic partners of the quarks and the
neutrinos.


title:
Construction of interlaced scrambled polynomial lattice rules of
  arbitrary high order

abstract:
  Higher order scrambled digital nets are randomized quasi-Monte Carlo rules
which have recently been introduced in [J. Dick, Ann. Statist., 39 (2011),
1372--1398] and shown to achieve the optimal rate of convergence of the root
mean square error for numerical integration of smooth functions defined on the
$s$-dimensional unit cube. The key ingredient there is a digit interlacing
function applied to the components of a randomly scrambled digital net whose
number of components is $ds$, where the integer $d$ is the so-called
interlacing factor. In this paper, we replace the randomly scrambled digital
nets by randomly scrambled polynomial lattice point sets, which allows us to
obtain a better dependence on the dimension while still achieving the optimal
rate of convergence. Our results apply to Owen's full scrambling scheme as well
as the simplifications studied by Hickernell, Matou\v{s}ek and Owen. We
consider weighted function spaces with general weights, whose elements have
square integrable partial mixed derivatives of order up to $\alpha\ge 1$, and
derive an upper bound on the variance of the estimator for higher order
scrambled polynomial lattice rules. Employing our obtained bound as a quality
criterion, we prove that the component-by-component construction can be used to
obtain explicit constructions of good polynomial lattice point sets. By first
constructing classical polynomial lattice point sets in base $b$ and dimension
$ds$, to which we then apply the interlacing scheme of order $d$, we obtain a
construction cost of the algorithm of order $\mathcal{O}(dsmb^m)$ operations
using $\mathcal{O}(b^m)$ memory in case of product weights, where $b^m$ is the
number of points in the polynomial lattice point set.


title:
Universality for Moving Stripes: A Hydrodynamic Theory of Polar Active
  Smectics

abstract:
  We present a hydrodynamic theory of polar active smectics, for systems both
with and without number conservation. For the latter, we find quasi long-ranged
smectic order in d=2 and long-ranged smectic order in d=3. In d=2 there is a
Kosterlitz-Thouless type phase transition from the smectic phase to the ordered
fluid phase driven by increasing the noise strength. For the number conserving
case, we find that giant number fluctuations are greatly suppressed by the
smectic order; that smectic order is long-ranged in d=3; and that nonlinear
effects become important in d=2.


title:
Most Maximally Monotone Operators Have a Unique Zero and a Super-regular
  Resolvent

abstract:
  Maximally monotone operators play important roles in optimization,
variational analysis and differential equations. Finding zeros of maximally
monotone operators has been a central topic. In a Hilbert space, we show that
most resolvents are super-regular, that most maximally monotone operators have
a unique zero and that the set of strongly monotone mapping is of first
category although each strongly monotone operator has a unique zero. The
results are established by applying the Baire Category Theorem to the space of
nonexpansive mappings.


title:
Study of field fluctuations and their localization in a thick braneworld
  generated by gravity non-minimally coupled to a scalar field with the
  Gauss-Bonnet term

abstract:
  In this work we study a scenario with a warped 5D smooth braneworld with 4D
Minkowski geometry builded from bulk scalar matter non-minimally coupled to
gravity with an additional Gauss-Bonnet term. We present exact solutions for
the full braneworld configuration in contrast to previous results where only
approximate solutions were constructed due to the highly non-linear character
of the relevant differential equations. These solutions allow us to study the
necessary conditions for the finiteness of the 4D Planck mass and additionally,
enables us to perform a more rigorous analysis of 4D gravity localization
compared to approximate approaches. It is remarkable that all the constructed
braneworld configurations lead to standard 4D gravity localization since they
contain a localized massless tensor mode (the graviton). We also analyze the
localization properties of scalar, vector and tensor fluctuation modes for the
constructed field configurations. We show that for the considered backgrounds,
only the massless tensor mode, i.e. the 4D graviton, is localized on the brane,
while the vector and scalar modes are not confined to the brane.


title:
Impurity scattering effect on the zero-energy peak of the local density
  of states in a multi-quantum vortex core

abstract:
  We theoretically study a non-magnetic impurity effect on the vortex bound
states of a multi-quantum vortex. The zero-energy peak of the local density of
states is investigated for vortex cores with the winding numbers 2 and 4 within
the framework of the quasiclassical theory of superconductivity. We find that
the zero-energy peaks, which appear away from the vortex center in the clean
limit, move towards the vortex center with increasing the impurity scattering
rate, resolving a contradiction between an experimental result and previous
theoretical predictions.


title: Fermi gases in one dimension: From Bethe Ansatz to experiments

abstract:
  This article reviews theoretical and experimental developments for
one-dimensional Fermi gases. Specifically, the experimentally realized
two-component delta-function interacting Fermi gas -- the Gaudin-Yang model --
and its generalisations to multi-component Fermi systems with larger spin
symmetries. The exact results obtained for Bethe ansatz integrable models of
this kind enable the study of the nature and microscopic origin of a wide range
of quantum many-body phenomena driven by spin population imbalance, dynamical
interactions and magnetic fields. This physics includes
Bardeen-Cooper-Schrieffer-like pairing, Tomonaga-Luttinger liquids, spin-charge
separation, Fulde-Ferrel-Larkin-Ovchinnikov-like pair correlations, quantum
criticality and scaling, polarons and the few-body physics of the trimer state
(trions). The fascinating interplay between exactly solved models and
experimental developments in one dimension promises to yield further insight
into the exciting and fundamental physics of interacting Fermi systems.


title: Nearly Optimal Private Convolution

abstract:
  We study computing the convolution of a private input $x$ with a public input
$h$, while satisfying the guarantees of $(\epsilon, \delta)$-differential
privacy. Convolution is a fundamental operation, intimately related to Fourier
Transforms. In our setting, the private input may represent a time series of
sensitive events or a histogram of a database of confidential personal
information. Convolution then captures important primitives including linear
filtering, which is an essential tool in time series analysis, and aggregation
queries on projections of the data.
  We give a nearly optimal algorithm for computing convolutions while
satisfying $(\epsilon, \delta)$-differential privacy. Surprisingly, we follow
the simple strategy of adding independent Laplacian noise to each Fourier
coefficient and bounding the privacy loss using the composition theorem of
Dwork, Rothblum, and Vadhan. We derive a closed form expression for the optimal
noise to add to each Fourier coefficient using convex programming duality. Our
algorithm is very efficient -- it is essentially no more computationally
expensive than a Fast Fourier Transform.
  To prove near optimality, we use the recent discrepancy lowerbounds of
Muthukrishnan and Nikolov and derive a spectral lower bound using a
characterization of discrepancy in terms of determinants.


title:
Boundedness of solutions for a class of impact oscillators with
  time-denpendent polynomial potentials

abstract:
  In this paper, we consider the boundedness of solutions for a class of impact
oscillators $$ \{{array}{ll} \displaystyle
\ddot{x}+x^{2n+1}+\sum_{i=0}^{2n}p_{i}(t)x^{i}=0,& \quad {\rm for}\quad x(t)>
0, x(t)\geq 0,& \dot{x}(t_{0}^{+})=-\dot{x}(t_{0}^{-}),& \quad {\rm if}\quad
x(t_{0})=0, {array}. $$ where $n\in\NN^{+}$, $p_{i}(t+1)=p_{i}(t)$ and
$p_{i}(t)\in C^5(\RR/\ZZ).$


title: To Obtain or not to Obtain CSI in the Presence of Hybrid Adversary

abstract:
  We consider the wiretap channel model under the presence of a hybrid, half
duplex adversary that is capable of either jamming or eavesdropping at a given
time. We analyzed the achievable rates under a variety of scenarios involving
different methods for obtaining transmitter CSI. Each method provides a
different grade of information, not only to the transmitter on the main
channel, but also to the adversary on all channels. Our analysis shows that
main CSI is more valuable for the adversary than the jamming CSI in both
delay-limited and ergodic scenarios. Similarly, in certain cases under the
ergodic scenario, interestingly, no CSI may lead to higher achievable secrecy
rates than with CSI.


title:
Recursive Pathways to Marginal Likelihood Estimation with
  Prior-Sensitivity Analysis

abstract:
  We investigate the utility to computational Bayesian analyses of a particular
family of recursive marginal likelihood estimators characterized by the
(equivalent) algorithms known as "biased sampling" or "reverse logistic
regression" in the statistics literature and "the density of states" in
physics. Through a pair of numerical examples (including mixture modeling of
the well-known galaxy data set) we highlight the remarkable diversity of
sampling schemes amenable to such recursive normalization, as well as the
notable efficiency of the resulting pseudo-mixture distributions for gauging
prior sensitivity in the Bayesian model selection context. Our key theoretical
contributions are to introduce a novel heuristic ("thermodynamic integration
via importance sampling") for qualifying the role of the bridging sequence in
this procedure and to reveal various connections between these recursive
estimators and the nested sampling technique.


title: On symmetry groups of oriented matroids

abstract:
  Symmetries of geometric structures such as hyperplane arrangements, point
configurations and polytopes have been studied extensively for a long time.
However, symmetries of oriented matroids, a common combinatorial abstraction of
them, are not understood well. In this paper, we aim to obtain a better
understanding of symmetries of oriented matroids. First, we put focus on
symmetries of matroids, and give a general construction that generates a
$3$-dimensional point configuration with a matroidal symmetry that cannot be
realized as a geometric symmetry. The construction is based on the observation
that every non-trivial rotation in the $2$-dimensional Euclidean space has a
unique fixed point but that there is no corresponding property for matroids.
The construction suggests that the lack of the fixed point theorem generates a
big gap between matroidal symmetries and geometric symmetries of point
configurations. Motivated by this insight, we study fixed-point properties for
symmetry groups of oriented matroids. For rotational symmetries of oriented
matroids, we prove a useful property, which corresponds to the uniqueness of
fixed points (in the rank $3$ case). Using it, we classify rotational and full
symmetry groups of simple oriented matroids of rank $3$. In addition, we define
fixed-point-admitting (FPA) property for subgroups of symmetry groups of
oriented matroids, and make classification of rotational symmetry groups with
FPA property of simple acyclic oriented matroids of rank $4$. We conjecture
that the symmetry group of every acyclic simple oriented matroid has FPA
property.


title: Pinning of a Bloch point by an atomic lattice

abstract:
  Bloch points are magnetic topological defects. The discrete nature of a
magnetic lattice creates a periodic potential that can pin a Bloch point. The
pinning force is of the order of the exchange constant, a few piconewtons in a
typical ferromagnet (permalloy). A domain wall containing a Bloch point can
have a sizable depinning field in the tens of oersted.


title:
Structured Lattice Codes for 2 \times 2 \times 2 MIMO Interference
  Channel

abstract:
  We consider the 2\times 2\times 2 multiple-input multipleoutput interference
channel where two source-destination pairs wish to communicate with the aid of
two intermediate relays. In this paper, we propose a novel lattice strategy
called Aligned Precoded Compute-and-Forward (PCoF). This scheme consists of two
phases: 1) Using the CoF framework based on signal alignment we transform the
Gaussian network into a deterministic finite field network. 2) Using linear
precoding (over finite field) we eliminate the end-to-end interference in the
finite field domain. Further, we exploit the algebraic structure of lattices to
enhance the performance at finite SNR, such that beyond a degree of freedom
result (also achievable by other means). We can also show that Aligned PCoF
outperforms time sharing in a range of reasonably moderate SNR, with increasing
gain as SNR increases.


title:
On the limit distribution of the normality measure of random binary
  sequences

abstract:
  We prove the existence of a limit distribution for the normalized normality
measure $\mathcal{N}(E_N)/\sqrt{N}$ (as $N \to \infty$) for random binary
sequences $E_N$, by this means confirming a conjecture of Alon, Kohayakawa,
Mauduit, Moreira and R{\"o}dl. The key point of the proof is to approximate the
distribution of the normality measure by the exiting probabilities of a
multidimensional Wiener process from a certain polytope.


title: The Higgs boson mixes with an SU(2) septet representation

abstract:
  We study a possibility of the Higgs boson, which consists of an SU(2) doublet
and a septet. The vacuum expectation value of a septet with hypercharge Y=2 is
known to preserve the electroweak rho parameter unity at the tree level.
Therefore, the septet can give significant contribution to the electroweak
symmetry breaking. Due to the mixing with the septet, the gauge coupling of the
standard-model-like Higgs boson is larger than that in the standard model. We
show the sizable VEV of the Higgs septet can be allowed under the constraint
from the electroweak precision data. The signal strengths of the Higgs boson
for the diphoton and a pair of weak gauge boson decay channels at the LHC are
enhanced, while those for the fermonic decay modes are suppressed. The mass of
additional neutral Higgs boson is also bounded by the current LHC data for the
standard model Higgs boson. We discussed the phenomenology of the multiply
charged Higgs bosons, which come from the septet.


title: A Singleton Bound for Lattice Schemes

abstract:
  In this paper, we derive a Singleton bound for lattice schemes and obtain
Singleton bounds known for binary codes and subspace codes as special cases. It
is shown that the modular structure affects the strength of the Singleton
bound. We also obtain a new upper bound on the code size for non-constant
dimension codes. The plots of this bound along with plots of the code sizes of
known non-constant dimension codes in the literature reveal that our bound is
tight for certain parameters of the code.


title: Ordinal length and the canonical topology

abstract:
  We extend the classical length function to an ordinal-valued invariant on the
class of all finite-dimensional Noetherian modules. We show how to calculate
this combinatorial invariant by means of the fundamental cycle of the module,
thus linking the lattice of submodules to homological properties of the module.
Using this, we define on a module its canonical topology, in which every
morphism is continuous.


title:
Theoretical study of spin-torque oscillator coupled with a nano-magnet
  by dipole-dipole interaction

abstract:
  The dynamics of a spin-torque-oscillator (STO) coupled with a nano-magnet
through dipole-dipole interaction was studied numerically by using the
macrospin model for the application of the STO as a read head sensor of hard
disk drives. We found that the current, which is required to induce the
oscillation of the free-layer (FL) of the STO, depends strongly on the distance
between the FL and the nano-magnet as well as on the relative orientation of
the magnetizations between them. To determine the dynamics of the STO it is
indispensable to consider the dynamics of the dipole-coupled nano-magnet. We
showed that we could detect the orientation of the magnetization of a
nano-magnet, or a recording-bit, by the modulation of the oscillation frequency
of the STO.


title:
Multiphoton Ionization as a clock to Reveal Molecular Dynamics with
  Intense Short X-ray Free Electron Laser Pulses

abstract:
  We investigate molecular dynamics of multiple ionization in N2 through
multiple core-level photoabsorption and subsequent Auger decay processes
induced by intense, short X-ray free electron laser pulses. The timing dynamics
of the photoabsorption and dissociation processes is mapped onto the kinetic
energy of the fragments. Measurements of the latter allow us to map out the
average internuclear separation for every molecular photoionization sequence
step and obtain the average time interval between the photoabsorption events.
Using multiphoton ionization as a tool of multiple-pulse pump-probe scheme, we
demonstrate the modification of the ionization dynamics as we vary the x-ray
laser pulse duration.


title:
Stabilization of Quantum Spin Hall Effect by Designed Removal of
  Time-Reversal Symmetry of Edge States

abstract:
  The quantum spin Hall (QSH) effect is known to be unstable to perturbations
violating time-reversal symmetry. We show that creating a narrow ferromagnetic
(FM) region near the edge of a QSH sample can push one of the
counterpropagating edge states to the inner boundary of the FM region, and
leave the other at the outer boundary, without changing their spin
polarizations and propagation directions. Since the two edge states are
spatially separated into different "lanes", the QSH effect becomes robust
against symmetry-breaking perturbations.


title: Confirming the molecular nature of the $Z_b(10610)$ and the $Z_b(10650)$

abstract:
  The decays of the $Z_b(10610)$ and the $Z_b(10650)$ to $\Upsilon(nS)\pi$,
$h_b(mP)\pi$ and $\chi_{bJ}(mP)\gamma$ ($n=1,2,3$, $m=1,2$ and $J=0,1,2$) are
investigated within a nonrelativistic effective field theory. It is argued
that, while the decays to $\Upsilon(nS) \pi$ suffer from potentially large
higher order corrections, the $P$-wave transitions of the $Z_b$ states offer
the best possibility to confirm the nature of the $Z_b$ states as molecular
states and to further study their properties. We give nontrivial and
parameter-free predictions for the ratios of various partial widths for final
states with $h_b(mP)\pi$ and $\chi_{bJ}(mP)\gamma$. In addition, the branching
fractions for the neutral $Z_b$-states to $\chi_{bJ}\gamma$ are predicted to be
of order $10^{-4}$--$10^{-3}$. This provides a fine test of the molecular
nature in future high-luminosity experiments.


title:
Activation cross-sections of longer lived products of proton induced
  nuclear reactions on cobalt up to 70 MeV

abstract:
  As a part of our series of studies on deuteron induced reaction on various
target materials excitation functions on natural cobalt have been measured by
using stacked-foil technique. In these measurements 51Cr, 55;56;57;58Co, 51Cr,
52;54;56Mn and 56;57Ni radioisotopes have been identified. For the above
isotopes the excitation functions were determined and compared with the
literature data and with the results of EMPIRE and TALYS calculations taken
from the TENDL 2011 library. The agreement with previous measurements was
acceptable and we could also determine new cross-section data.


title: The fundamental theorems for curves and surfaces in 3d Heisenberg group

abstract:
  We study the local equivalence problems of curves and surfaces in three
dimensional Heisenberg group via Cartans method of moving frames and Lie
groups, and find a complete set of invariants for curves and surfaces. For
surfaces, in terms of these invariants and their suitable derivatives, we also
give a Gaussian curvature fromula of the metric induced from the adapted metric
on Heisenberg group, and hence form a new formula for the Euler number of a
closed surface.


title: A Way to Understand the Mass Generation

abstract:
  We believe that the quantum 4-dimensional Minkowski space-time with the
force-fields gauge-group structure $SU_c(3) \times SU_L(2) \times U(1) \times
SU_f(3)$ built-in from the very beginning is the background for everything.
Thus, the self-repulsive, but ``related'', complex scalar fields $\Phi(1,2)$
(the Standard-Model Higgs), $\Phi(3,1)$ (the purely family Higgs), and
$\Phi(3,2)$ (the mixed family Higgs), with the first family label and the
second $SU_L(2)$ label, co-exist such that they generate all the masses if, and
only if, necessary. Note that the ``ignition'' channel is on the elusive
$\Phi(3,1)$ channel, yielding the prediction that the Standard-Model (SM) Higgs
mass $m_{SM}$ is half of the SM vacuum expectation value $v$. Before the
``ignition'', there is no mass terms, including the Higgs, the quarks, and the
leptons. Apart from the ``ignition'' term, all the couplings are dimensionless
and thus the theory is determined by the quantum 4-dimensional Minkowski
space-time. The multi-GeV or sub-sub-fermi $SU_f(3)$ family gauge fields
protect the lepton world from the QED Landau ghost and make them asymptotically
free. We try to discuss different ways to deal with infinities (ultraviolet
divergences) for the resultant Standard Model (as the consistent and complete
theory).


title: Extendable MDL

abstract:
  In this paper we show that combination of the minimum description length
principle and a exchange-ability condition leads directly to the use of
Jeffreys prior. This approach works in most cases even when Jeffreys prior
cannot be normalized. Kraft's inequality links codes and distributions but a
closer look at this inequality demonstrates that this link only makes sense
when sequences are considered as prefixes of potential longer sequences. For
technical reasons only results for exponential families are stated. Results on
when Jeffreys prior can be normalized after conditioning on a initializing
string are given. An exotic case where no initial string allow Jeffreys prior
to be normalized is given and some way of handling such exotic cases are
discussed.


title: Cell Migration Model with Multiple Chemical Compasses

abstract:
  A simple model is proposed that describes the various morphodynamic
principles of migrating cells from polar to amoeboidal motions. The model
equation is derived using competing internal cellular compass variables and
symmetries of the system. Fixed points for the $N = 2$ system are closely
investigated to clarify how the competition among polaritors explains the
observed morphodynamics. Response behaviors of cell--to--signal stimuli are
also investigated. This model will be useful for classifying high-dimensional
cell motions and investigating collective cellular behaviors.


title:
Non-Asymptotic and Second-Order Achievability Bounds for Coding With
  Side-Information

abstract:
  We present novel non-asymptotic or finite blocklength achievability bounds
for three side-information problems in network information theory. These
include (i) the Wyner-Ahlswede-Korner (WAK) problem of almost-lossless source
coding with rate-limited side-information, (ii) the Wyner-Ziv (WZ) problem of
lossy source coding with side-information at the decoder and (iii) the
Gel'fand-Pinsker (GP) problem of channel coding with noncausal state
information available at the encoder. The bounds are proved using ideas from
channel simulation and channel resolvability. Our bounds for all three problems
improve on all previous non-asymptotic bounds on the error probability of the
WAK, WZ and GP problems--in particular those derived by Verdu. Using our novel
non-asymptotic bounds, we recover the general formulas for the optimal rates of
these side-information problems. Finally, we also present achievable
second-order coding rates by applying the multidimensional Berry-Esseen theorem
to our new non-asymptotic bounds. Numerical results show that the second-order
coding rates obtained using our non-asymptotic achievability bounds are
superior to those obtained using existing finite blocklength bounds.


title: Stock Price Fluctuations in an Agent-Based Model with Market Liquidity

abstract:
  We study an agent-based stock market model with heterogeneous agents and
friction. Our model is based on that of Foellmer-Schweizer(1993): The process
of a stock price in a discrete-time framework is determined by temporary
equilibria via agents' excess demand functions, and the diffusion approximation
approach is applied to characterize the continuous-time limit (as transaction
intervals shorten) as a solution of the corresponding stochastic differential
equation (SDE). In this paper we further make the assumption that some of the
agents are bound by either short sale constraints or budget constraints. Then
we show that the continuous-time process of the stock price can be derived from
a certain SDE with oblique reflection. Moreover we find that the short sale
(respectively, budget) constraint causes overpricing (respectively,
underpricing).


title: Weighted Fej\'er Constants and Fekete Sets

abstract:
  We give the connections among the Fekete sets, the zeros of orthogonal
polynomials, $1(w)$-normal point systems, and the nodes of a stable and most
economical interpolatory process via the Fej\'er contants. Finally the
convergence of a weighted Gr\"unwald interpolation is proved.


title: Time and Knowability in Evolutionary Processes

abstract:
  Historical sciences like evolutionary biology reconstruct past events by
using the traces that the past has bequeathed to the present. The Markov Chain
Convergence Theorem and the Data Processing Inequality describe how the mutual
information between present and past is affected by how much time there is in
between. These two results are very general; they pertain to any process, not
just to the biological processes that occur in evolution. To study the
specifically biological question of how the present state of a lineage provides
information about its evolutionary past, we use a Moran process framework and
consider how the kind of evolutionary process (drift, and selection of various
kinds) at work in a lineage affects the epistemological relation of present to
past.


title:
Generalizing the Sampling Property of the Q-function for Error Rate
  Analysis of Cooperative Communication in Fading Channels

abstract:
  This paper extends some approximation methods that are used to identify
closed form Bit Error Rate (BER) expressions which are frequently utilized in
investigation and comparison of performance for wireless communication systems
in the literature. By using this group of approximation methods, some
expectation integrals, which are complicated to analyze and have high
computational complexity to evaluate through Monte Carlo simulations, are
computed. For these integrals, by using the sampling property of the integrand
functions of one or more arguments, reliable BER expressions revealing the
diversity and coding gains are derived. Although the methods we present are
valid for a larger class of integration problems, in this work we show the step
by step derivation of the BER expressions for a canonical cooperative
communication scenario in addition to a network coded system starting from
basic building blocks. The derived expressions agree with the simulation
results for a very wide range of signal-to-noise ratio (SNR) values.


title: Semi-flexible bimetal-based thermal energy harvesters

abstract:
  This paper introduces a new semi-flexible device able to turn thermal
gradients into electricity by using a curved bimetal coupled to an
electret-based converter. In fact, a two-steps conversion is carried out: (i) a
curved bimetal turns the thermal gradient into a mechanical oscillation that is
then (ii) converted into electricity thanks to an electrostatic converter using
electrets in Teflon (r). The semi-flexible and low cost design of these new
energy converters pave the way to mass production over large areas of thermal
energy harvesters. Raw output powers up to 13.46uW per device were reached on a
hot source at 60{\deg}C and forced convection. Then, a DC-to-DC flyback
converter has been sized to turn the energy harvesters' raw output powers into
a viable supply source for an electronic circuit (DC-3V). At the end, 10uW of
directly usable output power were reached with 3 devices, which is compatible
with Wireless Sensor Networks powering applications.
  Please cite as : S Boisseau et al 2013 Smart Mater. Struct. 22 025021
Available online at: http://iopscience.iop.org/0964-1726/22/2/025021/


title:
On the precoder design of a wireless energy harvesting node in linear
  vector Gaussian channels with arbitrary input distribution

abstract:
  A Wireless Energy Harvesting Node (WEHN) operating in linear vector Gaussian
channels with arbitrarily distributed input symbols is considered in this
paper. The precoding strategy that maximizes the mutual information along N
independent channel accesses is studied under non-causal knowledge of the
channel state and harvested energy (commonly known as offline approach). It is
shown that, at each channel use, the left singular vectors of the precoder are
equal to the eigenvectors of the Gram channel matrix. Additionally, an
expression that relates the optimal singular values of the precoder with the
energy harvesting profile through the Minimum Mean-Square Error (MMSE) matrix
is obtained. Then, the specific situation in which the right singular vectors
of the precoder are set to the identity matrix is considered. In this scenario,
the optimal offline power allocation, named Mercury Water-Flowing, is derived
and an intuitive graphical representation is presented. Two optimal offline
algorithms to compute the Mercury Water- Flowing solution are proposed and an
exhaustive study of their computational complexity is performed. Moreover, an
online algorithm is designed, which only uses causal knowledge of the harvested
energy and channel state. Finally, the achieved mutual information is evaluated
through simulation.


title: Bundles computing Clifford indices on trigonal curves

abstract:
  In this paper, we determine bundles which compute the higher Clifford indices
for trigonal curves.


title: Generalized Connectivity of Star Graphs

abstract:
  This paper shows that, for any integers $n$ and $k$ with $0\leqslant k
\leqslant n-2$, at least $(k+1)!(n-k-1)$ vertices or edges have to be removed
from an $n$-dimensional star graph to make it disconnected and no vertices of
degree less than $k$. The result gives an affirmative answer to the conjecture
proposed by Wan and Zhang [Applied Mathematics Letters, 22 (2009), 264-267].


title:
Emitting electrons spectra and acceleration processes in the jet of Mrk
  421: from low state to giant flare state

abstract:
  We investigate the electron energy distributions (EEDs) and the acceleration
processes in the jet of Mrk 421 through fitting the spectral energy
distributions (SEDs) in different active states in the frame of a one-zone
synchrotron self-Compton (SSC) model. After assuming two possible EEDs formed
in different acceleration models: the shock accelerated power-law with
exponential cut-off (PLC) EED and the stochastic turbulence accelerated
log-parabolic (LP) EED, we fit the observed SEDs of Mrk 421 in both low and
giant flare states by using the Markov Chain Monte Carlo (MCMC) method which
constrains the model parameters in a more efficient way. Our calculating
results indicate that (1) the PLC and LP models give comparably good fits for
the SED in low state, but the variations of model parameters from low state to
flaring can be reasonably explained only in the case of the PLC in low state;
and (2) the LP model gives better fits compared to the PLC model for the SED in
flare state, and the intra-day/night variability observed at GeV-TeV bands can
be accommodated only in the LP model. The giant flare may be attributed to the
stochastic turbulence re-acceleration of the shock accelerated electrons in low
state. Therefore, we may conclude that shock acceleration is dominant in low
state, while stochastic turbulence acceleration is dominant in flare state.
Moreover, our result shows that the extrapolated TeV spectra from the best-fit
SEDs from optical through GeV with the two EEDs are different. It should be
considered in caution when such extrapolated TeV spectra are used to constrain
extragalactic background light (EBL) models.


title:
Statistical features of freely decaying two-dimensional hydrodynamic
  turbulence

abstract:
  Statistical characteristics of freely decaying two-dimensional hydrodynamic
turbulence at high Reynolds numbers are numerically studied. In particular,
numerical experiments (with resolution up to $8192\times 8192$) provide a
Kraichnan-type turbulence spectrum $E_k\sim k^{-3}$. By means of spatial
filtration, it is found that the main contribution to the spectrum comes from
the sharp vorticity gradients in the form of quasi-shocks. Such
quasi-singularities are responsible for a strong angular dependence of the
spectrum owing to well-localized (in terms of the angle) jets with minor and/or
large overlapping. In each jet, the spectrum decreases as $k^{-3}$. The
behavior of the third-order structure function accurately agrees with Kraichnan
direct cascade concept corresponding to a constant enstrophy flux. It is shown
that the power law exponents $\zeta_n$ for higher structure functions grow more
slowly than the linear dependence of $n$, which testifies to turbulence
intermittency.

categories: physics.flu-dyn nlin.PS physics.comp-ph physics.geo-ph


title: Lorentz Covariant Lagrangians of Self-dual Gauge Fields

abstract:
  We extend the method of PST formulation to find a systematic way to
covariantize several non-covariant Lagrangians of self-dual gauge fields. We
derive in detail the necessary basic formulas which are used to prove the
existence of extra local symmetry that allows us to gauge fix the auxiliary
fields therein and non-covariant formulations are restored. We see that, the
extra local symmetry in the PST and PSST formulations, which describe the
covariant Lagrangians in the 6D decomposition of $6=1+5$ and $6=3+3$
respectively, can be expressed as a simple linear form in the field strength.
However, although in this paper we have found the covariant Lagrangians in the
other decomposition of $6=2+4$, the extra local symmetry of the gauge field
cannot be expressed as a simple linear form in the field strength. We present a
no-go theorem to prove this specific property. We also find other covariant
Lagrangians with more complex decomposition of spacetime.


title:
Ontology-based Data Access: A Study through Disjunctive Datalog, CSP,
  and MMSNP

abstract:
  Ontology-based data access is concerned with querying incomplete data sources
in the presence of domain-specific knowledge provided by an ontology. A central
notion in this setting is that of an ontology-mediated query, which is a
database query coupled with an ontology. In this paper, we study several
classes of ontology-mediated queries, where the database queries are given as
some form of conjunctive query and the ontologies are formulated in description
logics or other relevant fragments of first-order logic, such as the guarded
fragment and the unary-negation fragment. The contributions of the paper are
three-fold. First, we characterize the expressive power of ontology-mediated
queries in terms of fragments of disjunctive datalog. Second, we establish
intimate connections between ontology-mediated queries and constraint
satisfaction problems (CSPs) and their logical generalization, MMSNP formulas.
Third, we exploit these connections to obtain new results regarding (i)
first-order rewritability and datalog-rewritability of ontology-mediated
queries, (ii) P/NP dichotomies for ontology-mediated queries, and (iii) the
query containment problem for ontology-mediated queries.


title:
Investigation of dust properties of the proto-planetary nebula IRAS
  18276-1431

abstract:
  We investigate the circumstellar dust properties of the oxygen-rich bipolar
proto-planetary nebula IRAS 18276-1431 by means of two-dimensional radiative
transfer simulations of the circumstellar dust shell. The model geometry is
assumed to have a torus and an envelope. The parameters of the dust and the
dust shell are constrained by comparing the SED and NIR intensity and
polarisation data with the models. The polarisation in the envelope reaches 50
-- 60 % and is nearly constant in the H and K_S bands in the observations. This
weak wavelength dependence of the polarisation can be reproduced with a grain
size distribution function for the torus: 0.05 micron <= a with
n(a)=a^{-(p=5.5)}exp(-a/{a_c=0.3 micron}). The power index p is significantly
steeper than that for interstellar dust. Similar results have also been found
in some other PPNs and suggest that mechanisms that grind down large particles
may also have acted when the dust particles formed. The spectral opacity index
beta is found to be 0.6+/-0.5 from the millimeter fluxes. This low value
indicates the presence of large dust grains in the torus. We discuss two
possible dust models for the torus. One has a size distribution function of 1.0
micron <= a <= a_max=5,000.0 micron with n(a)=a^{-(p=2.5)} and the other is 1.0
micron <= a <= a_max=10,000.0 micron with n(a)=a^{-(p=3.5)}. The former has
beta of 0.633, but we are not able to find reasonable geometry parameters to
fit the SED in the infrared. The latter has beta of 1.12, but reproduces the
SED better over a wide wavelength range. With this dust model, the geometric
parameters are estimated as follows: the inner and outer radii are 30 AU and
1000 AU and the torus mass is 3.0 M_sun. Assuming an expansion velocity of 15
kms^{-1}, the torus formation time and mass-loss rate are found to be \sim300
yrs and \sim10^{-2}M_sun yr^{-1} respectively.


title:
Four-loop corrections with two closed fermion loops to fermion self
  energies and the lepton anomalous magnetic moment

abstract:
  We compute the eighth-order fermionic corrections involving two and three
closed massless fermion loops to the anomalous magnetic moment of the muon. The
required four-loop on-shell integrals are classified and explicit analytical
results for the master integrals are presented. As further applications we
compute the corresponding four-loop QCD corrections to the mass and wave
function renormalization constants for a massive quark in the on-shell scheme.


title:
Quantum discord and quantum phase transition in spin-1/2 frustrated
  Heisenberg chain

abstract:
  By using the concept of the quantum discord (QD), we study the spin-1/2
antiferromagnetic Heisenberg chain with next-nearest-neighbor interaction. Due
to the SU(2) symmetry and $Z_{2}$ symmetry in this system, we obtain the
analytical result of the QD and its geometric measure (GMQD), which is
determined by the two-site correlators. For the 4-site and 6-site cases, the
connection between GMQD (QD) and the eigenenergies was revealed. From the
analytical and numerical results, we find GMQD (QD) is an effective tool in
detecting both the first-order and the infinite-order quantum-phase-transition
points for the finite-size systems. Moreover, by using the entanglement
excitation energy and a universal frustration measure we consider the
frustration properties of the system and find a nonlinear dependence of the
GMQD on the frustration.


title: Coupling dimers to CDT - conceptual issues

abstract:
  Causal dynamical triangulations allows for a non perturbative approach to
quantum gravity. In this article a solution for dimers coupled to CDT is
presented and some of the conceptual problems that arise are reflected upon.


title: Perspectives on Balanced Sequences

abstract:
  We examine and compare several different classes of "balanced" block codes
over q-ary alphabets, namely symbol-balanced (SB) codes, charge-balanced (CB)
codes, and polarity-balanced (PB) codes. Known results on the maximum size and
asymptotic minimal redundancy of SB and CB codes are reviewed. We then
determine the maximum size and asymptotic minimal redundancy of PB codes and of
codes which are both CB and PB. We also propose efficient Knuth-like encoders
and decoders for all these types of balanced codes.


title:
Mathematical Formulation of an Optimal Execution Problem with Uncertain
  Market Impact

abstract:
  We study an optimal execution problem with uncertain market impact to derive
a more realistic market model. We construct a discrete-time model as a value
function for optimal execution. Market impact is formulated as the product of a
deterministic part increasing with execution volume and a positive stochastic
noise part. Then, we derive a continuous-time model as a limit of a
discrete-time value function. We find that the continuous-time value function
is characterized by a stochastic control problem with a Levy process.


title: On the birefringence of healthy and malaria-infected red blood cells

abstract:
  We have probed how the birefringence of a healthy red blood cell (RBC)
changes as it becomes infected by a malarial parasite. By analyzing the
polarization properties of light transmitted through a single,
optically-trapped cell we demarcate two types of birefringence: form
birefringence which depends on the shape of the cell and intrinsic
birefringence which is brought about by the presence of the parasite. We
quantitatively measure changes in the refractive index as normal RBS become
infected by a malarial parasite. Malarial infections are found to induce
changes in the cell's refractive index whose magnitude depends on the stage of
malarial infection; such changes were quantitatively explored and found to be
large, in the range 1.2 to 3$\times10^{-2}$. Our results have implications for
the development and use of non-invasive techniques that seek to quantify
changes in cell properties induced by pathological states accompanying diseases
like malaria. From a broader prespective, information forthcoming from our
trap-based experiments may stimulate physicists to initiate theoretical and
computational efforts that have a bearing on cell biology issues related to
diagnosis of diseases and therapeutics.


title:
Polarization effects in the quasi - elastic (p,2p) reaction with the
  nuclear S - shell protons at 1 GeV

abstract:
  The polarization of the secondary protons in the (p,2p) reaction with the S -
shell protons of nuclei 4He, 6Li, 12C, 28Si, 40Ca was measured at 1 GeV
unpolarized proton beam. The spin correlation parameters Cij for the 4He and
12C targets also were for the first time obtained as well. The polarization
measurements were performed by means of a two - arm magnetic spectrometer, each
arm of which was equipped with the multiwire proportional chamber polarimeter.
This experiment was aimed to study a modification of the proton - proton
scattering matrix in the nuclear medium.


title:
On a probabilistic interpretation of shape derivatives of Dirichlet
  groundstates with application to Fermion nodes

abstract:
  This paper considers Schr\"odinger operators, and presents a probabilistic
interpretation of the variation (or shape derivative) of the Dirichlet
groundstate energy when the associated domain is perturbed. This interpretation
relies on the distribution on the boundary of a stopped random process with
Feynman-Kac weights. Practical computations require in addition the explicit
approximation of the normal derivative of the groundstate on the boundary. We
then propose to use this formulation in the case of the so-called fixed node
approximation of fermion groundstates, defined by the bottom eigenelements of
the Schr\"odinger operator of a fermionic system with Dirichlet conditions on
the nodes (the set of zeros) of an initially guessed skew-symmetric function.
We show that the shape derivative of the fixed node energy vanishes if and only
if either (i) the distribution on the nodes of the stopped random process is
symmetric; or (ii) the nodes are exactly the zeros of a skew-symmetric
eigenfunction of the operator. We propose an approximation of the shape
derivative of the fixed node energy that can be computed with a Monte-Carlo
algorithm, which can be referred to as Nodal Monte-Carlo (NMC). The latter
approximation of the shape derivative also vanishes if and only if either (i)
or (ii) holds.