title:
Revisiting the Neyman-Scott model: an Inconsistent MLE or an Ill-defined
  Model?

abstract:
  The Neyman and Scott (1948) model is widely used to demonstrate a serious
weakness of the Maximum Likelihood (ML) method: it can give rise to
inconsistent estimators. The primary objective of this paper is to revisit this
example with a view to demonstrate that the culprit for the inconsistent
estimation is not the ML method but an ill-defined statistical model. It is
also shown that a simple recasting of this model renders it well-defined and
the ML method gives rise to consistent and asymptotically efficient estimators.


title: Electric field induced magnetic domain wall tilting

abstract:
  The inclination of the magnetic domain wall plane in electric field is
observed. The simple theoretical model of this phenomenon that takes into
account the spin flexoelectricity is proposed. The value of electric
polarization of the magnetic domain wall is estimated as 0.3{\mu}C/m^2 that
agrees well with the results of electric field driven magnetic domain wall
motion measurements.


title:
Coherent states for Landau levels: algebraic and thermodynamical
  properties

abstract:
  This work describes coherent states for a physical system governed by a
Hamiltonian operator, in two dimensional space, of spinless charged particles
subject to a perpendicular magnetic field B, coupled with a harmonic potential.
The underlying su(1, 1) Lie algebra and Barut-Girardello coherent states are
constructed and discussed. Then, the Berezin - Klauder - Toeplitz quantization,
also known as coherent state (or anti-Wick) quantization, is discussed. The
thermodynamics of such a quantum gas system is elaborated and analyzed.


title: Heavy gravitino in hybrid inflation

abstract:
  It is known that supersymmetric hybrid inflation model may require severe
tunings on the initial condition for large gravitino mass of order 100 - 1000
TeV due to the constant term in the superpotential. We propose a modified
hybrid inflation model, where the constant term is suppressed during inflation
and generated after inflation by replacing a constant term with dynamical
field. In this modified model, successful inflation consistent with large
gravitino mass takes place without severe tunings on the initial condition.
Constraint from cosmic strings is also relaxed.


title:
AABC: approximate approximate Bayesian computation when simulating a
  large number of data sets is computationally infeasible

abstract:
  Approximate Bayesian computation (ABC) methods perform inference on
model-specific parameters of mechanistically motivated parametric statistical
models when evaluating likelihoods is difficult. Central to the success of ABC
methods is computationally inexpensive simulation of data sets from the
parametric model of interest. However, when simulating data sets from a model
is so computationally expensive that the posterior distribution of parameters
cannot be adequately sampled by ABC, inference is not straightforward. We
present approximate approximate Bayesian computation" (AABC), a class of
methods that extends simulation-based inference by ABC to models in which
simulating data is expensive. In AABC, we first simulate a limited number of
data sets that is computationally feasible to simulate from the parametric
model. We use these data sets as fixed background information to inform a
non-mechanistic statistical model that approximates the correct parametric
model and enables efficient simulation of a large number of data sets by
Bayesian resampling methods. We show that under mild assumptions, the posterior
distribution obtained by AABC converges to the posterior distribution obtained
by ABC, as the number of data sets simulated from the parametric model and the
sample size of the observed data set increase simultaneously. We illustrate the
performance of AABC on a population-genetic model of natural selection, as well
as on a model of the admixture history of hybrid populations.


title:
Enhancement of pinning properties of superconducting thin films by
  graded pinning landscapes

abstract:
  A graded distribution of pinning centers (antidots) in superconducting MoGe
thin films has been investigated by magnetization and magneto-optical imaging.
The pinning landscape has maximum density at the border, decreasing
progressively towards the center. At high temperatures and low fields, where
this landscape mimics the vortex distribution predicted by the Bean model, an
increase of the critical current is observed. At low temperatures and fields,
the superconducting performance of the non-uniform sample is also improved due
to suppression of thermomagnetic avalanches. These findings emphasize the
relevance of non-uniform pinning landscapes, so far experimentally unexplored,
on the enhancement of pinning efficiency.


title:
Near-Infrared Spectral Monitoring of Pluto's Ices: Spatial Distribution
  and Secular Evolution

abstract:
  We report results from monitoring Pluto's 0.8 to 2.4 {\mu}m reflectance
spectrum with IRTF/SpeX on 65 nights over the dozen years from 2001 to 2012.
The spectra show vibrational absorption features of simple molecules CH4, CO,
and N2 condensed as ices on Pluto's surface. These absorptions are modulated by
the planet's 6.39 day rotation period, enabling us to constrain the
longitudinal distributions of the three ices. Absorptions of CO and N2 are
concentrated on Pluto's anti-Charon hemisphere, unlike absorptions of less
volatile CH4 ice that are offset by roughly 90{\deg} from the longitude of
maximum CO and N2 absorption. In addition to the diurnal variations, the
spectra show longer term trends. On decadal timescales, Pluto's stronger CH4
absorption bands have been getting deeper, while the amplitude of their diurnal
variation is diminishing, consistent with additional CH4 absorption at high
northern latitudes rotating into view as the sub-Earth latitude moves north (as
defined by the system's angular momentum vector). Unlike the CH4 absorptions,
Pluto's CO and N2 absorptions appear to be declining over time, suggesting more
equatorial or southerly distributions of those species. Comparisons of
geometrically-matched pairs of observations favor geometric explanations for
the observed secular changes in CO and N2 absorption, although seasonal
volatile transport could be at least partly responsible. The case for a
volatile transport contribution to the secular evolution looks strongest for
CH4 ice, despite it being the least volatile of the three ices.


title: Binomial coefficients involving infinite powers of primes

abstract:
  If p is a prime and n a positive integer, let v(n) denote the exponent of p
in n, and u(n)=n/p^{v(n)} the unit part of n. If k is a positive integer not
divisible by p, we show that the p-adic limit of (-1)^{pke} u((kp^e)!) as e
goes to infinity is a well-defined p-adic integer, which we call z_k. In terms
of these, we give a formula for the p-adic limit of binom{a p^e +c, b p^e +d)
as e goes to infinity, which we call binom(a p^\infty +c, b p^\infty +d). Here
a \ge b are positive integers, and c and d are integers.


title:
Minimal generators of the defining ideal of the Rees Algebra associated
  to a rational plane parameterization with \mu=2

abstract:
  We exhibit a set of minimal generators of the defining ideal of the Rees
Algebra associated to the ideal of three bivariate homogeneous polynomials
parametrizing a proper rational curve in projective plane, having a minimal
syzygy of degree 2.


title:
The Earliest Near-infrared Time-series Spectroscopy of a Type Ia
  Supernova

abstract:
  We present ten medium-resolution, high signal-to-noise ratio near-infrared
(NIR) spectra of SN 2011fe from SpeX on the NASA Infrared Telescope Facility
(IRTF) and Gemini Near-Infrared Spectrograph (GNIRS) on Gemini North, obtained
as part of the Carnegie Supernova Project. This data set constitutes the
earliest time-series NIR spectroscopy of a Type Ia supernova (SN Ia), with the
first spectrum obtained at 2.58 days past the explosion and covering -14.6 to
+17.3 days relative to B-band maximum. C I {\lambda}1.0693 {\mu}m is detected
in SN 2011fe with increasing strength up to maximum light. The delay in the
onset of the NIR C I line demonstrates its potential to be an effective tracer
of unprocessed material. For the first time in a SN Ia, the early rapid decline
of the Mg II {\lambda}1.0927 {\mu}m velocity was observed, and the subsequent
velocity is remarkably constant. The Mg II velocity during this constant phase
locates the inner edge of carbon burning and probes the conditions under which
the transition from deflagration to detonation occurs. We show that the Mg II
velocity does not correlate with the optical light-curve decline rate
{\Delta}m15. The prominent break at ~1.5 {\mu}m is the main source of concern
for NIR k-correction calculations. We demonstrate here that the feature has a
uniform time evolution among SNe Ia, with the flux ratio across the break
strongly correlated with {\Delta}m15. The predictability of the strength and
the onset of this feature suggests that the associated k-correction
uncertainties can be minimized with improved spectral templates.


title: Increase of Organization in Complex Systems

abstract:
  Measures of complexity and entropy have not converged to a single
quantitative description of levels of organization of complex systems. The need
for such a measure is increasingly necessary in all disciplines studying
complex systems. To address this problem, starting from the most fundamental
principle in Physics, here a new measure for quantity of organization and rate
of self-organization in complex systems based on the principle of least
(stationary) action is applied to a model system - the central processing unit
(CPU) of computers. The quantity of organization for several generations of
CPUs shows a double exponential rate of change of organization with time. The
exact functional dependence has a fine, S-shaped structure, revealing some of
the mechanisms of self-organization. The principle of least action helps to
explain the mechanism of increase of organization through quantity accumulation
and constraint and curvature minimization with an attractor, the least average
sum of actions of all elements and for all motions. This approach can help
describe, quantify, measure, manage, design and predict future behavior of
complex systems to achieve the highest rates of self organization to improve
their quality. It can be applied to other complex systems from Physics,
Chemistry, Biology, Ecology, Economics, Cities, network theory and others where
complex systems are present.


title:
The Stellar Obliquity and the Long-period planet in the HAT-P-17
  Exoplanetary System

abstract:
  We present the measured projected obliquity -- the sky-projected angle
between the stellar spin axis and orbital angular momentum -- of the inner
planet of the HAT-P-17 multi-planet system. We measure the sky-projected
obliquity of the star to be \lambda=19+/-15 degrees by modeling the
Rossiter-McLaughlin (RM) effect in Keck/HIRES radial velocities (RVs). The
anomalous RV time series shows an asymmetry relative to the midtransit time,
ordinarily suggesting a nonzero obliquity -- but in this case at least part of
the asymmetry may be due to the convective blueshift, increasing the
uncertainty in the determination of \lambda. We employ the semi-analytical
approach of Hirano et al. (2011) that includes the effects of macroturbulence,
instrumental broadening, and convective blueshift to accurately model the
anomaly in the net RV caused by the planet eclipsing part of the rotating star.
Obliquity measurements are an important tool for testing theories of planet
formation and migration. To date, the measured obliquities of ~50 Jovian
planets span the full range, from prograde to retrograde, with planets orbiting
cool stars preferentially showing alignment of stellar spins and planetary
orbits. Our results are consistent with this pattern emerging from tidal
interactions in the convective envelopes of cool stars and close-in planets. In
addition, our 1.8 years of new RVs for this system show that the orbit of the
outer planet is more poorly constrained than previously thought, with an
orbital period now in the range of 10-36 years.


title:
Real Time Event Detection in Astronomical Data Streams: Lessons from the
  VLBA

abstract:
  A new generation of observational science instruments is dramatically
increasing collected data volumes in a range of fields. These instruments
include the Square Kilometre Array (SKA), Large Synoptic Survey Telescope
(LSST), terrestrial sensor networks, and NASA satellites participating in
"decadal survey" missions. Their unprecedented coverage and sensitivity will
likely reveal wholly new categories of unexpected and transient events.
Commensal methods passively analyze these data streams, recognizing anomalous
events of scientific interest and reacting in real time. We report on a case
example: V-FASTR, an ongoing commensal experiment at the Very Long Baseline
Array (VLBA) that uses online adaptive pattern recognition to search for
anomalous fast radio transients. V-FASTR triages a millisecond-resolution
stream of data and promotes candidate anomalies for further offline analysis.
It tunes detection parameters in real time, injecting synthetic events to
continually retrain itself for optimum performance. This self-tuning approach
retains sensitivity to weak signals while adapting to changing instrument
configurations and noise conditions. The system has operated since July 2011,
making it the longest-running real time commensal radio transient experiment to
date.


title: Nested Lattice Codes for Gaussian Two-Way Relay Channels

abstract:
  In this paper, we consider a Gaussian two-way relay channel (GTRC), where two
sources exchange messages with each other through a relay. We assume that there
is no direct link between sources, and all nodes operate in full-duplex mode.
By utilizing nested lattice codes for the uplink (i.e., MAC phase), and
structured binning for the downlink (i.e., broadcast phase), we propose two
achievable schemes. Scheme 1 is based on compute and forward scheme of [1]
while scheme 2 utilizes two different lattices for source nodes based on a
three-stage lattice partition chain. We show that scheme 2 can achieve capacity
region at the high signal-to-noise ratio (SNR). Regardless all channel
parameters, the achievable rate of scheme 2 is within 0.2654 bit from the
cut-set outer bound for user 1. For user 2, the proposed scheme achieves within
0.167 bit from the outer bound if channel coefficient is larger than one, and
achieves within 0.2658 bit from the outer bound if channel coefficient is
smaller than one. Moreover, sum rate of the proposed scheme is within 0.334
bits from the sum capacity. These gaps for GTRC are the best gap-to-capacity
results to date.


title: A Search for Magnesium in Europa's Atmosphere

abstract:
  Europa's tenuous atmosphere results from sputtering of the surface. The trace
element composition of its atmosphere is therefore related to the composition
of Europa's surface. Magnesium salts are often invoked to explain Galileo Near
Infrared Mapping Spectrometer spectra of Europa's surface, thus magnesium may
be present in Europa's atmosphere. We have searched for magnesium emission in
Hubble Space Telescope Faint Object Spectrograph archival spectra of Europa's
atmosphere. Magnesium was not detected and we calculate an upper limit on the
magnesium column abundance. This upper limit indicates that either Europa's
surface is depleted in magnesium relative to sodium and potassium, or magnesium
is not sputtered as efficiently resulting in a relative depletion in its
atmosphere.


title: Tightly Circumscribed Regular Polygons

abstract:
  A regular polygon circumscribing another regular polygon (with a different
side number) may be tightened to minimize the difference of both areas. The
manuscripts computes the optimum result under the restriction that both
polygons are concentric, and obtains limits if the process is repeated in a
two-dimensional Babuschka-doll fashion with side numbers increasing or
decreasing by one or stepping through the prime numbers. The new aspect
compared to the circumscription discussed in the literature so far is that
further squeezing of the outer polygon is possible as we drop the requirement
of drawing intermediate spacing circles between the polygon pairs.


title:
Statistical properties of swarms of self-propelled particles with
  repulsions across the order-disorder transition

abstract:
  We study dynamic self-organisation and order-disorder transitions in a
two-dimensional system of self-propelled particles. Our model is a variation of
the Vicsek model, where particles align the motion to their neighbours but
repel each other at short distances. We use computer simulations to measure the
orientational order parameter for particle velocities as a function of
intensity of internal noise or particle density. We show that in addition to
the transition to an ordered state on increasing the particle density, as
reported previously, there exists a transition into a disordered phase at the
higher densities, which can be attributed to the destructive action of the
repulsions. We demonstrate that the transition into the ordered phase is
accompanied by the onset of algebraic behaviour of the two-point velocity
correlation function and by a non-monotonous variation of the velocity
relaxation time. The critical exponent for the decay of the velocity
correlation function in the ordered phase depends on particle concentration at
low densities but assumes a universal value in more dense systems.


title:
Fixed Points of Generalized Approximate Message Passing with Arbitrary
  Matrices

abstract:
  The estimation of a random vector with independent components passed through
a linear transform followed by a componentwise (possibly nonlinear) output map
arises in a range of applications. Approximate message passing (AMP) methods,
based on Gaussian approximations of loopy belief propagation, have recently
attracted considerable attention for such problems. For large random
transforms, these methods exhibit fast convergence and admit precise analytic
characterizations with testable conditions for optimality, even for certain
non-convex problem instances. However, the behavior of AMP under general
transforms is not fully understood. In this paper, we consider the generalized
AMP (GAMP) algorithm and relate the method to more common optimization
techniques. This analysis enables a precise characterization of the GAMP
algorithm fixed-points that applies to arbitrary transforms. In particular, we
show that the fixed points of the so-called max-sum GAMP algorithm for MAP
estimation are critical points of a constrained maximization of the posterior
density. The fixed-points of the sum-product GAMP algorithm for estimation of
the posterior marginals can be interpreted as critical points of a certain free
energy.


title: On expanders from the action of GL(2,Z)

abstract:
  Consider the undirected graph $G_n=(V_n, E_n)$ where $V_n = (Z/nZ)^2$ and
$E_n$ contains an edge from $(x,y)$ to $(x+1,y)$, $(x,y+1)$, $(x+y,y)$, and
$(x,y+x)$ for every $(x,y) \in V_n$. Gabber and Galil, following Margulis, gave
an elementary proof that ${G_n}$ forms an expander family. In this note, we
present a somewhat simpler proof of this fact, and demonstrate its utility by
isolating a key property of the linear transformations $(x,y) -> (x+y,x),
(x,y+x)$ that yields expansion.
  As an example, consider any invertible, integral matrix $S \in GL_2(Z)$ and
let $G^S_n = (V_n, E^S_n)$ where $E^S_n$ contains, for every $(x,y) \in V_n$,
an edge from $(x,y)$ to $(x+1,y)$, $(x,y+1)$, $S(x,y)$, and $S^T(x,y)$, where
$S^T$ denotes the transpose of $S$. Then {G_n^S} forms an expander family if
and only if a related infinite graph has positive Cheeger constant. This latter
property turns out to be elementary to analyze and can be used to show that
{G_n^S} are expanders precisely when the trace of S is non-zero and S is not
equal to its transpose. We also present some other generalizations.


title: Safety of Deferred Update in Transactional Memory

abstract:
  Transactional memory allows the user to declare sequences of instructions as
speculative \emph{transactions} that can either \emph{commit} or \emph{abort}.
If a transaction commits, it appears to be executed sequentially, so that the
committed transactions constitute a correct sequential execution. If a
transaction aborts, none of its instructions can affect other transactions.
  The popular criterion of \emph{opacity} requires that the views of aborted
transactions must also be consistent with the global sequential order
constituted by committed ones. This is believed to be important, since
inconsistencies observed by an aborted transaction may cause a fatal
irrecoverable error or waste of the system in an infinite loop. Intuitively, an
opaque implementation must ensure that no intermediate view a transaction
obtains before it commits or aborts can be affected by a transaction that has
not started committing yet, so called \emph{deferred-update} semantics.
  In this paper, we intend to grasp this intuition formally. We propose a
variant of opacity that explicitly requires the sequential order to respect the
deferred-update semantics. We show that our criterion is a safety property,
i.e., it is prefix- and limit-closed. Unlike opacity, our property also ensures
that a serialization of a history implies serializations of its prefixes.
Finally, we show that our property is equivalent to opacity if we assume that
no two transactions commit identical values on the same variable, and present a
counter-example for scenarios when the "unique-write" assumption does not hold.


title: Denominators and Differences of Boundary Slopes for (1,1)-Knots

abstract:
  We show that every nonzero integer occurs in the denominator of a boundary
slope for infinitely many (1,1)-knots and that infinitely many (1,1)-knots have
boundary slopes of arbitrarily small difference. Specifically, we prove that
for any integers m, n > 1 with n odd the exterior of the Montesinos knot
K(-1/2, m/(2m \pm 1), 1/n) in S^3 contains an essential surface with boundary
slope r = 2(n-1)^2/n if m is even and 2(n+1)^2/n if m is odd. If n > 4m, we
prove that K(-1/2, m/(2m+1), 1/n) also has a boundary slope whose difference
with r is (8m-2)/(n^2-4mn+n), which decreases to 0 as n increases. All of these
knots are (1,1)-knots.


title: Fault-Tolerant Shortest Paths - Beyond the Uniform Failure Model

abstract:
  The overwhelming majority of survivable (fault-tolerant) network design
models assume a uniform scenario set. Such a scenario set assumes that every
subset of the network resources (edges or vertices) of a given cardinality $k$
comprises a scenario. While this approach yields problems with clean
combinatorial structure and good algorithms, it often fails to capture the true
nature of the scenario set coming from applications.
  One natural refinement of the uniform model is obtained by partitioning the
set of resources into faulty and secure resources. The scenario set contains
every subset of at most $k$ faulty resources. This work studies the
Fault-Tolerant Path (FTP) problem, the counterpart of the Shortest Path problem
in this failure model. We present complexity results alongside exact and
approximation algorithms for FTP. We emphasize the vast increase in the
complexity of the problem with respect to its uniform analogue, the
Edge-Disjoint Paths problem.


title: Lifting automorphisms of quotients of adjoint representations

abstract:
  Let $\mathfrak g_i$ be a simple complex Lie algebra, $1\leq i \leq d$, and
let $G=G_1\times...\times G_d$ be the corresponding adjoint group. Consider the
$G$-module $V=\oplus r_i\mathfrak g_i$ where $r_i\geq 1$ for all $i$. We say
that $V$ is \emph{large} if all $r_i\geq 2$ and $r_i\geq 3$ if $G_i$ has rank
1. In [Schwarz12] we showed that when $V$ is large any algebraic automorphism
$\psi$ of the quotient $Z:= V//G$ lifts to an algebraic mapping $\Psi\colon
V\to V$ which sends the fiber over $z$ to the fiber over $\psi(z)$, $z\in Z$.
(Most cases were already handled in [Kuttler11]). We also showed that one can
choose a biholomorphic lift $\Psi$ such that $\Psi(gv)=\sigma(g)\Psi(v)$, $g\in
G$, $v\in V$, where $\sigma$ is an automorphism of $G$. This leaves open the
following questions: Can one lift holomorphic automorphisms of $Z$? Which
automorphisms lift if $V$ is not large? We answer the first question in the
affirmative and also answer the second question. Part of the proof involves
establishing the following result for $V$ large. Any algebraic differential
operator of order $k$ on $Z$ lifts to a $G$-invariant algebraic differential
operator of order $k$ on $V$. We also consider the analogues of the questions
above for actions of compact Lie groups.


title: Deterministic Constructions for Large Girth Protograph LDPC Codes

abstract:
  The bit-error threshold of the standard ensemble of Low Density Parity Check
(LDPC) codes is known to be close to capacity, if there is a non-zero fraction
of degree-two bit nodes. However, the degree-two bit nodes preclude the
possibility of a block-error threshold. Interestingly, LDPC codes constructed
using protographs allow the possibility of having both degree-two bit nodes and
a block-error threshold. In this paper, we analyze density evolution for
protograph LDPC codes over the binary erasure channel and show that their
bit-error probability decreases double exponentially with the number of
iterations when the erasure probability is below the bit-error threshold and
long chain of degree-two variable nodes are avoided in the protograph. We
present deterministic constructions of such protograph LDPC codes with girth
logarithmic in blocklength, resulting in an exponential fall in bit-error
probability below the threshold. We provide optimized protographs, whose
block-error thresholds are better than that of the standard ensemble with
minimum bit-node degree three. These protograph LDPC codes are theoretically of
great interest, and have applications, for instance, in coding with strong
secrecy over wiretap channels.


title:
Simultaneous Information and Energy Transfer: A Two-User MISO
  Interference Channel Case

abstract:
  This paper considers the sum rate maximization problem of a two-user
multiple-input single-output interference channel with receivers that can
scavenge energy from the radio signals transmitted by the transmitters. We
first study the optimal transmission strategy for an ideal scenario where the
two receivers can simultaneously decode the information signal and harvest
energy. Then, considering the limitations of the current circuit technology, we
propose two practical schemes based on TDMA, where, at each time slot, the
receiver either operates in the energy harvesting mode or in the information
detection mode. Optimal transmission strategies for the two practical schemes
are respectively investigated. Simulation results show that the three schemes
exhibit interesting tradeoff between achievable sum rate and energy harvesting
requirement, and do not dominate each other in terms of maximum achievable sum
rate.


title: Generalized Einstein-Maxwell field equations in the Palatini formalism

abstract:
  We derive a new set of field equations within the framework of the Palatini
formalism.These equations are a natural generalization of the Einstein-Maxwell
equations which arise by adding a function $\mathcal{F}(\mathcal{Q})$, with
$\mathcal{Q}\equiv F^{\alpha\beta}F_{\alpha\beta}$ to the Palatini Lagrangian
$f(R,Q)$.The result we obtain can be viewed as the coupling of gravity with a
nonlinear extension of the electromagnetic field.In addition,a new method is
introduced to solve the algebraic equation associated to the Ricci tensor.


title:
Full automorphism groups of association schemes based on isotropic
  subspaces

abstract:
  The set of all subspaces of a given dimension in a finite classical polar
space has a structure of a symmetric association scheme. If the dimension is
zero, this is the scheme of the collinearity graph of the space; If the
dimension is maximum, it is the dual polar scheme. In this note, we determine
the full automorphism group of this scheme.


title: Probabilistic simulation of mesoscopic "Schr\"odinger cat" states

abstract:
  We carry out probabilistic phase-space sampling of mesoscopic Schr\"odinger
cat quantum states, demonstrating multipartite Bell violations for up to 60
qubits. We use states similar to those generated in photonic and ion-trap
experiments. These results show that mesoscopic quantum superpositions are
directly accessible to probabilistic sampling, and we analyze the properties of
sampling errors. We also demonstrate dynamical simulation of super-decoherence
in ion traps. Our computer simulations can be either exponentially faster or
slower than experiment, depending on the correlations measured.


title: Probability Distribution of a Passive Scalar in Isotropic Turbulence

abstract:
  In this letter, we present developments of the Hamiltonian approach to
problems of the probability distribution for a passive scalar in isotropic
turbulence, and also considers specific applications of the modified
Prelle-Singer procedure to turbulence models. The following key questions are
discussed and solved: what is the general dynamical structure of the resulting
scale equation permitted by passive scalar turbulence models? What are the
general requirements of the relations between canonical variables and the
canonical variabes representation for turbulence by using canonical variables?
It is shown that the existence of the Haniltonian representation in turbulence
is a privilege of only turbulence systems for which the variational principle
of least action is impossible The master equation of the probability
distribution of a passive scalar in isotropic turbulence can also be deduced
explicitly.

categories: physics.flu-dyn cond-mat.stat-mech math-ph math.MP nlin.SI


title:
Sequential Distributed Detection in Energy-Constrained Wireless Sensor
  Networks

abstract:
  The recently proposed sequential distributed detector based on
level-triggered sampling operates as simple as the decision fusion techniques
and at the same time performs as well as the data fusion techniques. Hence, it
is well suited for resource-constrained wireless sensor networks. However, in
practical cases where sensors observe discrete-time signals, the random
overshoot above or below the sampling thresholds considerably degrades the
performance of the considered detector. We propose, for systems with stringent
energy constraints, a novel approach to tackle this problem by encoding the
overshoot into the time delay between the sampling time and the transmission
time. Specifically, each sensor computes the local log-likelihood ratio (LLR)
and samples it using level-triggered sampling. Then, it transmits a single
pulse to the fusion center (FC) after a transmission delay that is proportional
to the overshoot, as in pulse position modulation (PPM). The FC, upon receiving
a bit decodes the corresponding overshoot and recovers the transmitted LLR
value. It then updates the approximate global LLR and compares it with two
threshold to either make a decision or to continue the sequential process. We
analyze the asymptotic average detection delay performance of the proposed
scheme. We then apply the proposed sequential scheme to target detection in
wireless sensor networks under the four Swerling fluctuating target models. It
is seen that the proposed sequential distributed detector offers significant
performance advantage over conventional decision fusion techniques.


title:
An Extragradient-Based Alternating Direction Method for Convex
  Minimization

abstract:
  In this paper, we consider the problem of minimizing the sum of two convex
functions subject to linear linking constraints. The classical alternating
direction type methods usually assume that the two convex functions have
relatively easy proximal mappings. However, many problems arising from
statistics, image processing and other fields have the structure that while one
of the two functions has easy proximal mapping, the other function is smoothly
convex but does not have an easy proximal mapping. Therefore, the classical
alternating direction methods cannot be applied. To deal with the difficulty,
we propose in this paper an alternating direction method based on
extragradients. Under the assumption that the smooth function has a Lipschitz
continuous gradient, we prove that the proposed method returns an
$\epsilon$-optimal solution within $O(1/\epsilon)$ iterations. We apply the
proposed method to solve a new statistical model called fused logistic
regression. Our numerical experiments show that the proposed method performs
very well when solving the test problems. We also test the performance of the
proposed method through solving the lasso problem arising from statistics and
compare the result with several existing efficient solvers for this problem;
the results are very encouraging indeed.


title: Local and global structure of connections on nonarchimedean curves

abstract:
  Consider a vector bundle with connection on a p-adic analytic curve in the
sense of Berkovich. We collect some improvements and refinements of recent
results on the structure of such connections, and on the convergence of local
horizontal sections. This builds on work from the author's 2010 book and on
subsequent improvements by Baldassarri and Poineau-Pulita.


title: One-Particle Measurement of the Antiproton Magnetic Moment

abstract:
  \DeclareRobustCommand{\pbar}{\HepAntiParticle{p}{}{}\xspace}
\DeclareRobustCommand{\p}{\HepParticle{p}{}{}\xspace}
\DeclareRobustCommand{\mup}{$\mu_{p}${}{}\xspace}
\DeclareRobustCommand{\mupbar}{$\mu_{\pbar}${}{}\xspace}
\DeclareRobustCommand{\muN}{$\mu_N${}{}\xspace
  For the first time a single trapped \pbar is used to measure the \pbar
magnetic moment ${\bm\mu}_{\pbar}$. The moment ${\bm\mu}_{\pbar} = \mu_{\pbar}
{\bm S}/(\hbar/2)$ is given in terms of its spin ${\bm S}$ and the nuclear
magneton (\muN) by $\mu_{\pbar}/\mu_N = -2.792\,845 \pm 0.000\,012$. The 4.4
parts per million (ppm) uncertainty is 680 times smaller than previously
realized. Comparing to the proton moment measured using the same method and
trap electrodes gives $\mu_{\pbar}/\mu_p = -1.000\,000 \pm 0.000\,005$ to 5
ppm, for a proton moment ${\bm{\mu}}_{p} = \mu_{p} {\bm S}/(\hbar/2)$,
consistent with the prediction of the CPT theorem.


title:
Absence of finite size correction at the combinatorial point of the
  integrable higher spin XXZ chain

abstract:
  We investigate the integrable higher spin XXZ chain at the Razumov-Stroganov
point. We present a method to evaluate the exact value of the eigenvalue which
is conjectured to correspond to the groundstate of the Hamiltonian for finite
size chain from the Baxter Q operator. This allows us to examine the exact
total energy difference between different number of total sites, from which we
find strong evidence for the absence of finite size correction to the
groundstate energy.


title: Rooting out the Rumor Culprit from Suspects

abstract:
  Suppose that a rumor originating from a single source among a set of suspects
spreads in a network, how to root out this rumor source? With the a priori
knowledge of suspect nodes and an observation of infected nodes, we construct a
maximum a posteriori (MAP) estimator to identify the rumor source using the
susceptible-infected (SI) model. The a priori suspect set and its associated
connectivity bring about new ingredients to the problem, and thus we propose to
use local rumor center, a generalized concept based on rumor centrality, to
identify the source from suspects. For regular tree-type networks of node
degree {\delta}, we characterize Pc(n), the correct detection probability of
the estimator upon observing n infected nodes, in both the finite and
asymptotic regimes. First, when every infected node is a suspect, Pc(n)
asymptotically grows from 0.25 to 0.307 with {\delta} from 3 to infinity, a
result first established in Shah and Zaman (2011, 2012) via a different
approach; and it monotonically decreases with n and increases with {\delta}.
Second, when the suspects form a connected subgraph of the network, Pc(n)
asymptotically significantly exceeds the a priori probability if {\delta}>2,
and reliable detection is achieved as {\delta} becomes large; furthermore, it
monotonically decreases with n and increases with {\delta}. Third, when there
are only two suspects, Pc(n) is asymptotically at least 0.75 if {\delta}>2; and
it increases with the distance between the two suspects. Fourth, when there are
multiple suspects, among all possible connection patterns, that they form a
connected subgraph of the network achieves the smallest detection probability.
Our analysis leverages ideas from the Polya's urn model in probability theory
and sheds insight into the behavior of the rumor spreading process not only in
the asymptotic regime but also for the general finite-n regime.


title:
Global large solutions to 3-D inhomogeneous Navier-Stokes system with
  one slow variable

abstract:
  In this paper, we are concerned with the global wellposedness of 3-D
inhomogeneous incompressible Navier-Stokes equations \eqref{1.3} in the
critical Besov spaces with the norm of which are invariant by the scaling of
the equations and under a nonlinear smallness condition on the isentropic
critical Besov norm to the fluctuation of the initial density and the critical
anisotropic Besov norm of the horizontal components of the initial velocity
which have to be exponentially small compared with the critical anisotropic
Besov norm to the third component of the initial velocity. The novelty of this
results is that the isentropic space structure to the homogeneity of the
initial density function is consistent with the propagation of anisotropic
regularity for the velocity field. In the second part, we apply the same idea
to prove the global wellposedness of \eqref{1.3} with some large data which are
slowly varying in one direction.


title:
Equitability Analysis of the Maximal Information Coefficient, with
  Comparisons

abstract:
  A measure of dependence is said to be equitable if it gives similar scores to
equally noisy relationships of different types. Equitability is important in
data exploration when the goal is to identify a relatively small set of
strongest associations within a dataset as opposed to finding as many non-zero
associations as possible, which often are too many to sift through. Thus an
equitable statistic, such as the maximal information coefficient (MIC), can be
useful for analyzing high-dimensional data sets. Here, we explore both
equitability and the properties of MIC, and discuss several aspects of the
theory and practice of MIC. We begin by presenting an intuition behind the
equitability of MIC through the exploration of the maximization and
normalization steps in its definition. We then examine the speed and optimality
of the approximation algorithm used to compute MIC, and suggest some directions
for improving both. Finally, we demonstrate in a range of noise models and
sample sizes that MIC is more equitable than natural alternatives, such as
mutual information estimation and distance correlation.


title:
Multiple-Antenna Interference Channel with Receive Antenna Joint
  Processing and Real Interference Alignment

abstract:
  We consider a constant $K$-user Gaussian interference channel with $M$
antennas at each transmitter and $N$ antennas at each receiver, denoted as a
$(K,M,N)$ channel. Relying on a result on simultaneous Diophantine
approximation, a real interference alignment scheme with joint receive antenna
processing is developed. The scheme is used to provide new proofs for two
previously known results, namely 1) the total degrees of freedom (DoF) of a
$(K, N, N)$ channel is $NK/2$; and 2) the total DoF of a $(K, M, N)$ channel is
at least $KMN/(M+N)$. We also derive the DoF region of the $(K,N,N)$ channel,
and an inner bound on the DoF region of the $(K,M,N)$ channel.


title: Hierarchical Data Representation Model - Multi-layer NMF

abstract:
  In this paper, we propose a data representation model that demonstrates
hierarchical feature learning using nsNMF. We extend unit algorithm into
several layers. Experiments with document and image data successfully
discovered feature hierarchies. We also prove that proposed method results in
much better classification and reconstruction performance, especially for small
number of features. feature hierarchies.


title: On the Cauchy problem for axi-symmetric vortex rings

abstract:
  We consider the classical Cauchy problem for the 3d Navier-Stokes equation
with the initial vorticity $\omega_0$ concentrated on a circle, or more
generally, a linear combination of such data for circles with common axis of
symmetry. We show that natural approximations of the problem obtained by
smoothing the initial data satisfy good a-priori estimates which enable us to
conclude that the original problem with the singular initial distribution of
vorticity has a solution. We impose no restriction on the size of the initial
data.


title: Quasi-Equiangular Frame (QEF) : A New Flexible Configuration of Frame

abstract:
  Frame theory is a powerful tool in the domain of signal processing and
communication. Among its numerous configurations, the ones which have drawn
much attention recently are Equiangular Tight Frame (ETF) and Grassmannian
Frame. These frames both have some kind of optimality in coherence, thus bring
robustness or optimal performance in applications such as digital fingerprint,
erasure channels, and Compressive Sensing. However, too strict constraint on
existence and construction of ETF and Grassmannian Frame became the main
obstacle for widespread use. In this paper, we propose a new configuration of
frame: Quasi-Equiangular Frame, as a compromise but more convenient and
flexible approximation of ETF and Grassmannian Frame. We will give formal
definition of Quasi-Equiangular Frame and analyze its relationship with ETF and
Grassmannian frame. Furthermore, for popularity of ETF and Grassmannian frame
in Compressive Sensing, we utilize the technique of random matrices to obtain
asymptotical concentration estimation of the Restricted Isometry Constant (RIC)
of Quasi-Equiangular Frame with respect to its key parameter.


title: Aplikasi belajar membaca iqro' berbasis mobile

abstract:
  IPTEK and IMTAQ should be followed by knowledge of the ability in reading the
hijaiyah letters as Al Qur-an base. Current people are so busy with their
activities thats way authors develop this mobile application using pocket pc.
The development of this research using waterfall model. Authors use the
programming language of Microsoft Visual BASIC.Net. Authors also use Photoshop
to prepare the image of every letter. In Indonesia, there six level in reading
Al Qur-an, but for the purpose of thi research authors only use Iqro-1 until
Iqro-4. This mobile application also enriched with the voice for every letter
image.


title: On the pattern of black hole information release

abstract:
  We propose a step towards a resolution to black hole information paradox by
analyzing scattering amplitudes of a complex scalar field around a
Schwarzschild black hole. The scattering cross section reveals much information
on the incoming state but exhibits flux loss at the same time. The flux loss
should be temporary, and indicate mass growth of the black hole. The black hole
should Hawking-radiate subsequently, thereby, compensating for the flux loss.
{By examining the purity issue}, we comment on the possibility that information
bleaching may be the key to the paradox.


title:
Two equivalence theorems of different kinds of optimal control problems
  for Schr\"{o}dinger equations

abstract:
  This paper builds up two equivalence theorems for different kinds of optimal
control problems of internally controlled Schr\"{o}dinger equations. The first
one concerns with the equivalence of the minimal norm and the minimal time
control problems. (The minimal time control problems are also called the first
type of optimal time control problems.) The targets of the aforementioned two
kinds of problems are the origin of the state space. The second one deals with
the equivalence of three optimal control problems which are optimal target
control problems, optimal norm control problems and the second type of optimal
time control problems. These two theorems were estabilished for heat equations
in [18] and [17] respectively.


title: Existence and Regularity for a Curvature Dependent Variational Problem

abstract:
  It is proved that smooth closed curves of given length minimizing the
principal eigenvalue of the Schr\"odinger operator $-\frac{d^2}{ds^2}+\kappa^2$
exist. Here $s$ denotes the arclength and $\kappa$ the curvature. These
minimizers are automatically planar, analytic, convex curves. The straight
segment, traversed back and forth, is the only possible exception that becomes
admissible in a more generalized setting. In proving this, we overcome the
difficulty from a lack of coercivity and compactness by a combination of
methods.


title: Real Space Renormalization in Statistical Mechanics

abstract:
  This paper discusses methods for the construction of approximate real space
renormalization transformations in statistical mechanics. In particular, it
compares two methods of transformation: the "potential-moving" approach most
used in the period 1975-1980 and the "rewiring method" as it has been developed
in the last five years. These methods both employ a parameter, called \chi,
that measures the complexity of the localized stochastic variable forming the
basis of the analysis. Both methods are here exemplified by calculations in
terms of fixed points for the smallest possible values of \chi. These
calculations describe three models for two-dimensional systems: The Ising model
solved by Onsager, the tricritical point of that model, and the three-state
Potts model. The older method, often described as lower bound renormalization
theory, provides a heuristic method giving reasonably accurate results for
critical indices at the lowest degree of complexity, i.e. \chi=2. In contrast,
the rewiring method, employing "singular value decomposition", does not perform
as well for low \chi values but offers an error that apparently decreases
slowly toward zero as \chi is increased. It appears likely that no such
improvement occurs in the older approach.
  A detailed comparison of the two methods is performed, with a particular eye
to describing the reasons why they are so different. For example, the old
method quite naturally employed fixed points for its analysis; these are hard
to use in the newer approach. A discussion is given of why the fixed point
approach proves to be hard in this context.
  In the new approach the calculated the thermal critical indices are
satisfactory for the smallest values of \chi but hardly improve as \chi is
increased, while the magnetic critical indices do not agree well with the known
theoretical values.


title: An improvement to k-nearest neighbor classifier

abstract:
  K-Nearest neighbor classifier (k-NNC) is simple to use and has little design
time like finding k values in k-nearest neighbor classifier, hence these are
suitable to work with dynamically varying data-sets. There exists some
fundamental improvements over the basic k-NNC, like weighted k-nearest
neighbors classifier (where weights to nearest neighbors are given based on
linear interpolation), using artificially generated training set called
bootstrapped training set, etc. These improvements are orthogonal to space
reduction and classification time reduction techniques, hence can be coupled
with any of them. The paper proposes another improvement to the basic k-NNC
where the weights to nearest neighbors are given based on Gaussian distribution
(instead of linear interpolation as done in weighted k-NNC) which is also
independent of any space reduction and classification time reduction technique.
We formally show that our proposed method is closely related to non-parametric
density estimation using a Gaussian kernel. We experimentally demonstrate using
various standard data-sets that the proposed method is better than the existing
ones in most cases.


title:
A loop group method for Demoulin surfaces in the 3-dimensional real
  projective space

abstract:
  For a surface in the 3-dimensional real projective space, we define a Gauss
map, which is a quadric in $\mathbb R^{4}$ and called the first-order Gauss
map. It will be shown that the surface is a Demoulin surface if and only if the
first-order Gauss map is conformal, and the surface is a projective minimal
coincidence surface or a Demoulin surface if and only if the first-order Gauss
map is harmonic. Moreover for a Demoulin surface, it will be shown that the
first-order Gauss map can be obtained by the natural projection of the Lorentz
primitive map into a 6-symmetric space. We also characterize Demoulin surfaces
via a family of flat connections on the trivial bundle $\D \times \SL$ over a
simply connected domain $\mathbb{D}$ in the Euclidean 2-plane.


title: The Tate conjecture for K3 surfaces in odd characteristic

abstract:
  We show that the classical Kuga-Satake construction gives rise, away from
characteristic 2, to an open immersion from the moduli of primitively polarized
K3 surfaces (of any fixed degree) to a certain regular integral model for a
Shimura variety of orthogonal type. This allows us to attach to every polarized
K3 surface in odd characteristic an abelian variety such that divisors on the
surface can be identified with certain endomorphisms of the attached abelian
variety. In turn, this reduces the Tate conjecture for K3 surfaces over
finitely generated fields of odd characteristic to a version of the Tate
conjecture for certain endomorphisms on the attached Kuga-Satake abelian
variety, which we prove. As a by-product of our methods, we also show that the
moduli stack of primitively polarized K3 surfaces of degree 2d is
quasi-projective and, when d is not divisible by p^2, is geometrically
irreducible in characteristic p. We indicate how the same method applies to
prove the Tate conjecture for co-dimension 2 cycles on cubic fourfolds.


title: Ordered Partitions and Drawings of Rooted Plane Trees

abstract:
  We study the bounded regions in a generic slice of the hyperplane arrangement
in $\mathbb{R}^n$ consisting of the hyperplanes defined by $x_i$ and $x_i+x_j$.
The bounded regions are in bijection with several classes of combinatorial
objects, including the ordered partitions of $[n]$ all of whose left-to-right
minima occur at odd locations and the drawings of rooted plane trees with $n+1$
vertices. These are sequences of rooted plane trees such that each tree in a
sequence can be obtained from the next one by removing a leaf.


title: Explicit Constructions of Quasi-Uniform Codes from Groups

abstract:
  We address the question of constructing explicitly quasi-uniform codes from
groups. We determine the size of the codebook, the alphabet and the minimum
distance as a function of the corresponding group, both for abelian and some
nonabelian groups. Potentials applications comprise the design of almost affine
codes and non-linear network codes.


title: Improving Monte Carlo simulations by Dirichlet forms

abstract:
  Equipping the probability space with a local Dirichlet form with square field
operator \Gamma and generator A allows to improve Monte Carlo simulations of
expectations and densities as soon as we are able to simulate a random variable
X together with \Gamma[X] and A[X]. We give examples on the Wiener space, on
the Poisson space and on the Monte Carlo space. When X is real-valued we give
an explicit formula yielding the density at the speed of the law of large
numbers.


title:
Certification of projection-based reduced order modelling in
  computational homogenisation by the Constitutive Relation Error

abstract:
  In this paper, we propose upper and lower error bounding techniques for
reduced order modelling applied to the computational homogenisation of random
composites. The upper bound relies on the construction of a reduced model for
the stress field. Upon ensuring that the reduced stress satisfies the
equilibrium in the finite element sense, the desired bounding property is
obtained. The lower bound is obtained by defining a hierarchical enriched
reduced model for the displacement. We show that the sharpness of both error
estimates can be seamlessly controlled by adapting the parameters of the
corresponding reduced order model.


title: Optimal Locally Repairable Codes via Rank-Metric Codes

abstract:
  This paper presents a new explicit construction for locally repairable codes
(LRCs) for distributed storage systems which possess all-symbols locality and
maximal possible minimum distance, or equivalently, can tolerate the maximal
number of node failures. This construction, based on maximum rank distance
(MRD) Gabidulin codes, provides new optimal vector and scalar LRCs. In
addition, the paper also discusses mechanisms by which codes obtained using
this construction can be used to construct LRCs with efficient repair of failed
nodes by combination of LRC with regenerating codes.


title: Integer-valued polynomials over matrices and divided differences

abstract:
  Let $D$ be an integrally closed domain with quotient field $K$ and $n$ a
positive integer. We give a characterization of the polynomials in $K[X]$ which
are integer-valued over the set of matrices $M_n(D)$ in terms of their divided
differences. A necessary and sufficient condition on $f\in K[X]$ to be
integer-valued over $M_n(D)$ is that, for each $k$ less than $n$, the $k$-th
divided difference of $f$ is integral-valued on every subset of the roots of
any monic polynomial over $D$ of degree $n$. If in addition the intersection of
the maximal ideals of finite index is $(0)$ then it is sufficient to check the
above conditions on subsets of the roots of monic irreducible polynomials of
degree $n$, that is, conjugate integral elements of degree $n$ over $D$.


title:
Cavity piezooptomechanics: piezoelectrically excited, optically
  transduced optomechanical resonators

abstract:
  We present a monolithic integrated aluminum nitride (AlN) optomechanical
resonator in which the mechanical motion is actuated by piezoelectric force and
the displacement is transduced by a high-Q optical cavity. The AlN
optomechanical resonator is excited from a radio-frequency electrode via a
small air gap to eliminate resonator-to-electrode loss. We observe the
electrically excited mechanical motion at 47.3 MHz, 1.04 GHz, and 3.12 GHz,
corresponding to the 1st, 2nd, and 4th radial-contour mode of the wheel
resonator respectively. An equivalent circuit model is developed to describe
the observed Fano-like resonance spectrum.


title:
On Possible Influence of Space Weather on Agricultural Markets:
  Necessary Conditions and Probable Scenarios

abstract:
  We present the results of study of a possible relationship between the space
weather and terrestrial markets of agricultural products. It is shown that to
implement the possible effect of space weather on the terrestrial harvests and
prices, a simultaneous fulfillment of three conditions is required: 1)
sensitivity of local weather (cloud cover, atmospheric circulation) to the
state of space weather; 2) sensitivity of the area of specific agricultural
crops to the weather anomalies (belonging to the area of risk farming); 3)
relative isolation of the market, making it difficult to damp the price hikes
by the external food supplies. Four possible scenarios of the market response
to the modulations of local terrestrial weather via the solar activity are
described. The data sources and analysis methods applied to detect this
relationship are characterized. We describe the behavior of 22 European markets
during the medieval period, in particular, during the Maunder minimum
(1650-1715). We demonstrate a reliable manifestation of the influence of space
weather on prices, discovered in the statistics of intervals between the price
hikes and phase price asymmetry. We show that the effects of phase price
asymmetry persist even during the early modern period in the U.S. in the
production of the durum wheat. Within the proposed approach, we analyze the
statistics of depopulation in the eighteenth and nineteenth century Iceland,
induced by the famine due to a sharp livestock reduction owing to, in its turn,
the lack of foodstuff due to the local weather anomalies. A high statistical
significance of temporal matching of these events with the periods of extreme
solar activity is demonstrated. We discuss the possible consequences of the
observed global climate change in the formation of new areas of risk farming,
sensitive to space weather.


title: Composite Leptons at the LHC

abstract:
  In some models of electro-weak interactions the W and Z bosons are considered
composites, made up of spin-one-half subconstituents. In these models a spin
zero counterpart of the W and Z boson naturally appears, whose higher mass can
be attributed to a particular type of hyperfine spin interaction among the
various subconstituents. Recently it has been argued that the scalar state
could be identified with the newly discovered Higgs (H) candidate. Here we use
the known spin splitting between the W/Z and H states to infer, within the
framework of a purely phenomenological model, the relative strength of the
spin-spin interactions. The results are then applied to the lepton sector, and
used to crudely estimate the relevant spin splitting between the two lowest
states. Our calculations in many ways parallels what is done in the SU(6) quark
model, where most of the spin splittings between the lowest lying baryon and
meson states are reasonably well accounted for by a simple color hyperfine
interaction, with constituent (color-dressed) quark masses.


title: Approximation of Polyhedral Surface Uniformization

abstract:
  We present a constructive approach for approximating the conformal map
(uniformization) of a polyhedral surface to a canonical domain in the plane.
The main tool is a characterization of convex spaces of quasiconformal
simplicial maps and their approximation properties. As far as we are aware,
this is the first algorithm proved to approximate the uniformization of general
polyhedral surfaces.


title:
Interference of Topologically Protected Edge States in Silicene
  Nanoribbons

abstract:
  Silicene is a two-dimensional quantum spin-Hall insulator. We study the edge
channels of silicene nanoribbons from the viewpoint of the topological
protection and the interference between the two edges. It is found that the
behaviors of the helical edge channels (HECs) are completely different between
the armchair and zigzag edges. The penetration depths $\xi$ of the HEC is
antiproportional to the spin-orbit gap for the armchair edge $\xi_{\rm arm}
\sim \hbar v_\text{F}/ \Delta$ ($v_\text{F}$: the Fermi velocity, $\Delta$: the
gap due to the spin-orbit interaction), while it remains as short as the
lattice constant for the zigzag edge. Zero-energy states disappear in armchair
nanoribbons due to an interference of two edge states, while they remains in
zigzag nanoribbons even if the width $W$ is quite narrow. The gap $\delta$ of
HECs behaves as $\delta \sim \hbar v_\text{F}/W$ for $\Delta=0$, and as $\delta
\sim \Delta \exp[- W/\xi_{\rm arm}]$ for $\Delta\not=0$ for armchair
nanoribbons, while it remains essentially zero irrespectively of $\Delta$ for
zigzag nanoribbons.


title: DG quivers of smooth rational surfaces

abstract:
  Let X be a smooth rational surface. We calculate a DG quiver of a full
exceptional collection of line bundles on X obtained by an augmentation from a
strong exceptional collection on the minimal model of X. In particular, we
calculate canonical DG algebras of smooth toric surfaces.


title:
Lov\'asz's Theta Function, R\'enyi's Divergence and the Sphere-Packing
  Bound

abstract:
  Lov\'asz's bound to the capacity of a graph and the the sphere-packing bound
to the probability of error in channel coding are given a unified presentation
as information radii of the Csisz\'ar type using the R{\'e}nyi divergence in
the classical-quantum setting. This brings together two results in coding
theory that are usually considered as being of a very different nature, one
being a "combinatorial" result and the other being "probabilistic". In the
context of quantum information theory, this difference disappears.


title: An "Umbrella" Bound of the Lov\'asz-Gallager Type

abstract:
  We propose a novel approach for bounding the probability of error of discrete
memoryless channels with a zero-error capacity based on a combination of
Lov\'asz' and Gallager's ideas. The obtained bounds are expressed in terms of a
function $\vartheta(\rho)$, introduced here, that varies from the cut-off rate
of the channel to the Lov\'azs theta function as $\rho$ varies from 1 to
$\infty$ and which is intimately related to Gallager's expurgated coefficient.
The obtained bound to the reliability function, though loose in its present
form, is finite for all rates larger than the Lov\'asz theta function.


title:
Continuous and first-order jamming transition in crossing pedestrian
  traffic flows

abstract:
  After reviewing the main results obtained within a model for the intersection
of two perpendicular flows of pedestrians, we present a new finding: the
changeover of the jamming transition from continuous to first order when the
size of the intersection area increases.


title: Iron-Based Superconductors as Parity Odd Superconductors

abstract:
  Parity is a fundamental quantum number to classify a state of matter.
Materials rarely possess ground states with odd parity. We show that the
superconducting state in iron-based superconductors is classified as an odd
parity s-wave spin-singlet pairing state in a single trilayer FeAs/Se, the
building block of the materials. In a low energy effective model constructed on
the Fe square bipartite lattice, the superconducting order parameter in this
state is a combination of a s-wave normal pairing between two sublattices and a
s-wave $\eta$-pairing within the sublattices. Parity conservation was violated
in proposed superconducting states in the past. The state has a fingerprint
with a real space sign inversion between the top and bottom As/Se layers. The
results demonstrate iron-based superconductors being a new quantum state of
matter and suggest that the measurement of the odd parity can establish
fundamental principles related to high temperature superconducting mechanism.


title:
The Schrodinger-Foldy relativistic canonical quantum mechanics and the
  derivation of the Dirac equation

abstract:
  The detailed consideration of the relativistic canonical quantum-mechanical
model of an arbitrary spin-multiplet is given. The group-theoretical analysis
of the algebra of experimentally observables physical quantities for the spin
1/2 doublet is presented. It is shown that both the Foldy-Wouthuysen equation
for the fermionic spin 1/2 doublet and the Dirac equation in its local
representation are the consequences of the relativistic canonical quantum
mechanics of the corresponding doublet. The mathematically well-defined
consideration on the level of modern axiomatic approaches to the field theory
is provided. The hypothesis of the antiparticle negative mass is discussed
briefly in the section conclusions.


title:
Brane cosmology from observational surveys and its comparison with
  standard FRW cosmology

abstract:
  Several dark energy models on the brane are investigated. They are compared
with corresponding theories in the frame of 4d Friedmann-Robertson-Walker
cosmology. To constrain the parameters of the models considered, recent
observational data, including SNIa apparent magnitude measurements, baryon
acoustic oscillation results, Hubble parameter evolution data and matter
density perturbations are used. Explicit formulas of the so-called {\it
state-finder} parameters in teleparallel theories are obtained that could be
useful to test these models and to establish a link between Loop Quantum
Cosmology and Brane Cosmology. It is concluded that a joint analysis as the one
developed here allows to estimate, in a very convenient way, possible deviation
of the real universe cosmology from the standard Friedmann-Robertson-Walker
one.

categories: gr-qc astro-ph.CO hep-th math-ph math.MP


title: On AVCs with Quadratic Constraints

abstract:
  In this work we study an Arbitrarily Varying Channel (AVC) with quadratic
power constraints on the transmitter and a so-called "oblivious" jammer (along
with additional AWGN) under a maximum probability of error criterion, and no
private randomness between the transmitter and the receiver. This is in
contrast to similar AVC models under the average probability of error criterion
considered in [1], and models wherein common randomness is allowed [2] -- these
distinctions are important in some communication scenarios outlined below.
  We consider the regime where the jammer's power constraint is smaller than
the transmitter's power constraint (in the other regime it is known no positive
rate is possible). For this regime we show the existence of stochastic codes
(with no common randomness between the transmitter and receiver) that enables
reliable communication at the same rate as when the jammer is replaced with
AWGN with the same power constraint. This matches known information-theoretic
outer bounds. In addition to being a stronger result than that in [1] (enabling
recovery of the results therein), our proof techniques are also somewhat more
direct, and hence may be of independent interest.


title:
A coherent acceleration search of the Parkes multi-beam pulsar survey -
  techniques and the discovery and timing of 16 pulsars

abstract:
  A fully coherent acceleration search algorithm has been applied to the Parkes
multi- beam pulsar survey of the Galactic plane to search for previously
undiscovered relativistic binary pulsars. The search has resulted in the
discovery of 16 pulsars including a binary millisecond pulsar and an
intermittent pulsar. Despite a number of promising candidates there have been
no new discoveries of relativistic binary pulsars. Here we detail the
acceleration search performed in our analysis and present coherent timing
solutions for each of pulsars discovered. In light of the lack of discoveries
of relativistic binary pulsars, we also discuss the technique of acceleration
searching and its effectiveness in finding these systems.


title:
Gravitational interaction of celestial bodies and black holes with
  particle dark matter

abstract:
  The particles of a dark matter due to gravitational interaction deviate from
straight trajectories in the vicinity of a massive body. This causes their
density to become inhomogeneous. The developed density contrast causes a
gravitation attraction force acting upon the body proportional to its mass
squared. Since this effect depends on the body's velocity, it causes a specific
reference frame to stand out. The force is similar to an anisotropic drag,
which can be negative in some directions. The mean drag force, averaged over
all direction, is nonpositive. We can expect some observational manifestation
of the considered effect for supermassive black holes in galaxies.


title:
Capacity Optimization through Sensing Threshold Adaptation for Cognitive
  Radio Networks

abstract:
  In this paper we propose the capacity optimization over sensing threshold for
sensing-based cognitive radio networks. The objective function of the proposed
optimization is to maximize the capacity at the secondary user subject to the
constraints on the transmit power and the sensing threshold in order to protect
the primary user. The defined optimization problem is a convex optimization
over the transmit power and the sensing threshold where the concavity on
sensing threshold is proved. The problem is solved by using Lagrange duality
decomposition method in conjunction with a subgradient iterative algorithm and
the numerical results show that the proposed optimization can lead to
significant capacity maximization for the secondary user as long as the primary
user can afford.


title: Construction of Nilpotent Jordan Algebras Over any Arbitrary Fields

abstract:
  We give a computional method to construct and classify nilpotent Jordan
algebras over any arbitrary fields by the second cohomolgy of nilpotent Jordan
algebras of low dimension "analogue of Skjelbred-Sund method", we see that
every nilpotent Jordan algebras can be constructed by the second cohomolgy of
nilpotent Jordan algebras of low dimension. We use this method to classify
nilpotent Jordan algebras up to dimension three over any field and nilpotent
Jordan algebras of dimension four over an algebraic closed field of
characteristic not 2 and over the real field R. Also commutative nilpotent
associative algebras are classified, we show that there are up to isomorphism
13 nilpotent Jordan algebras of dimension 4 over an algebraic closed field of
characteristic not 2, four of those are not associative, yielding 9 commutative
nilpotent associative algebras. Also up to isomorphism there are 17 nilpotent
Jordan algebras of dimension 4 over the real field R, five of those are not
associative, yielding 12 commutative nilpotent associative algebras.


title:
Lattice Approximation for Stochastic Reaction Diffusion Equations with
  One-Sided Lipschitz Condition

abstract:
  We consider strong convergence of the finite differences approximation in
space for stochastic reaction diffusion equations with multiplicative noise
under a one-sided Lipschitz condition only. We derive convergence with an
implicit rate depending on the regularity of the exact solution. This can be
made explicit if the variational solution has more than its canonical spatial
regularity. As an application, spatially extended FitzHugh-Nagumo systems with
noise are considered.


title:
Relic gravitational waves in the frame of slow-roll inflation with a
  power-law potential and the detection

abstract:
  We obtained the analytic solutions of relic gravitational waves (RGWs) for
the slow-roll inflation with a power-law form potential of the scalar field,
$V=\lambda\phi^n$. Based on a reasonable range of $n$ constrained by cosmic
microwave background (CMB) observations, we give tight constraints of the
tensor-to-scalar ratio $r$ and the inflation expansion index $\beta$ for the
fixed scalar spectral index $n_s$. Even though, the spectrum of RGWs in low
frequencies is hardly depends on any parameters, the high frequency parts will
be affected by several parameters, such as $n_s$, the reheating temperature
$T_{RH}$ and the index $\beta_s$ describing the expansion from the end of
inflation to the reheating process. We analyzed in detail all the factors which
would affect the spectrum of RGWs in high frequencies including the quantum
normalization. We found that the future GW detectors SKA, eLISA, BBO and DECIGO
are promising to catch the signals of RGWs.
  Furthermore, BBO and DECIGO have the potential not only to distinguish the
spectra with different parameters but also to examine the validity of the
quantum normalization.


title: On $k$-jet field approximations to geodesic deviation equations

abstract:
  Let $M$ be a smooth manifold and $\mathcal{S}$ a semi-spray defined on a
sub-bundle $\mathcal{C}$ of the tangent bundle $TM$. In this work it is proved
that the only non-trivial $k$-jet approximation to the exact geodesic deviation
equation of $\mathcal{S}$, linear on the deviation functions and invariant
under an specific class of local coordinate transformations is the Jacobi
equation. However, if the linearity property on the dependence in the deviation
functions is not imposed, then there are differential equations whose solutions
admit $k$-jet approximations and are invariant under arbitrary coordinate
transformations. As an example of higher order geodesic deviation equations we
study the first and second order geodesic deviation equations for a Finsler
spray.


title:
Geometrical and hydrodynamic aspects of five-dimensional Schwarzschild
  black hole

abstract:
  Exploiting the five-dimensional Schwarzschild black hole, we study the
geometrical natures of the higher dimensional black hole to yield the (6+1)
dimensional global embedding Minkowski space structure. We next obtain the
Hawking temperature on this five-dimensional manifold, whose result is
different from the four-dimensional one. On the contrary, the radial component
of the Einstein equation for the massive particles or photons on the
five-dimensional spacetime is shown to have the same form as the
four-dimensional black hole one. Moreover, we construct the effective potential
on equatorial plane of the restricted three-brane to investigate the behavior
of the particles or photons on this restricted brane.


title:
Absolute Continuity under Time Shift of Trajectories and Related
  Stochastic Calculus

abstract:
  The paper is concerned with a class of two-sided stochastic processes of the
form $X=W+A$. Here $W$ is a two-sided Brownian motion with random initial data
at time zero and $A\equiv A(W)$ is a function of $W$. Elements of the related
stochastic calculus are introduced. In particular, the calculus is adjusted to
the case when $A$ is a jump process. Absolute continuity of $(X,P_{\sbnu})$
under time shift of trajectories is investigated. For example under various
conditions on the initial density with respect to the Lebesgue measure,
$m=d\bnu/dx$, and on $A$ with $A_0=0$ we verify % {eqnarray*}
\frac{P_{\sbnu}(dX_{\cdot -t})}{P_{\sbnu}(dX_\cdot)}=\frac{m(X_{-t})}
{m(X_0)}\cdot\prod_i|\nabla_{W_0}X_{-t}|_i {eqnarray*} % a.e. where the product
is taken over all coordinates. Here $\sum_i(\nabla_{W_0}X_{-t})_i$ is the
divergence of $X_{-t}$ with respect to the initial position. Crucial for this
is the {\it temporal homogeneity} in the sense that $X(W_{\cdot
+v}+A_v\1)=X_{\cdot+v}(W)$, $v\in {\Bbb R}$, where $A_v\1$ is the trajectory
taking the constant value $A_v (W)$.
  By means of such a density, partial integration relative to the generator of
the process $X$ is established. Relative compactness of sequences of such
processes is established.


title: Kondo Effect in the Presence of Spin-Orbit Coupling

abstract:
  Recently, a series of noncentrosymmetric superconductors has been a subject
of considerable interest since the discovery of superconductivity in CePt_3Si.
In noncentrosymmetric materials, the degeneracy of bands is lifted in the
presence of spin-orbit coupling. This will bring about new effects in the Kondo
effect since the band degeneracy plays an important role in the scattering of
electrons by localized spins. We investigate the single-impurity Kondo problem
in the presence of spin-orbit coupling. We examine the effect of spin-orbit
coupling on the scattering of conduction electrons, by using the Green's
function method, for the s-d Hamiltonian, with employing a decoupling
procedure. As a result, we obtain a closed system of equations of Green's
functions, from which we can calculate physical quantities. The Kondo
temperature T_K is estimated from a singularity of Green's functions. We show
that T_K is reduced as the spin-orbit coupling constant \alpha is increased.
When 2\alpha k_F is comparable to or greater than k_BT_K(\alpha=0), T_K shows
an abrupt decrease as a result of the band splitting. This suggests a Kondo
collapse accompanied with a sharp decrease of T_K. The log T-dependence of the
resistivity will be concealed by the spin-orbit interaction.


title: Brute force searching, the typical set and Guesswork

abstract:
  Consider the situation where a word is chosen probabilistically from a finite
list. If an attacker knows the list and can inquire about each word in turn,
then selecting the word via the uniform distribution maximizes the attacker's
difficulty, its Guesswork, in identifying the chosen word. It is tempting to
use this property in cryptanalysis of computationally secure ciphers by
assuming coded words are drawn from a source's typical set and so, for all
intents and purposes, uniformly distributed within it. By applying recent
results on Guesswork, for i.i.d. sources it is this equipartition ansatz that
we investigate here. In particular, we demonstrate that the expected Guesswork
for a source conditioned to create words in the typical set grows, with word
length, at a lower exponential rate than that of the uniform approximation,
suggesting use of the approximation is ill-advised.


title:
Multi-command Tactile and Auditory Brain Computer Interface based on
  Head Position Stimulation

abstract:
  We study the extent to which vibrotactile stimuli delivered to the head of a
subject can serve as a platform for a brain computer interface (BCI) paradigm.
Six head positions are used to evoke combined somatosensory and auditory (via
the bone conduction effect) brain responses, in order to define a multimodal
tactile and auditory brain computer interface (taBCI). Experimental results of
subjects performing online taBCI, using stimuli with a moderately fast
inter-stimulus interval (ISI), validate the taBCI paradigm, while the
feasibility of the concept is illuminated through information transfer rate
case studies.


title: Impact of turbulence on the stratified flow around small particles

abstract:
  We study the turbulent flow of the density-stratified fluid around a small
translating (either passively or self-propelled) particle. It was found
recently [A. M. Ardekani and R. Stocker, Phys. Rev. Lett. vol. 105, 084502
(2010)] that without turbulence, the familiar Stokes flow is dramatically
altered by the stratification. Stratification-induced inhomogeneity "turns on"
the buoyancy introducing a new "cutoff" or "screening" length scale for the
flow, yielding closed streamlines and a faster (exponential-like) decay of
velocity. This result, however, did not account for the potential role of the
background turbulence, intrinsically present in many aquatic environments.
Turbulence mixes the density opposing the effect. Here we derive and solve the
advection-diffusion equation that describes the interplay of turbulent mixing,
diffusion of the stratifying agent and buoyancy. We derive an exact expression
for fluctuations due to weak background turbulence and show that stronger
turbulence can completely change the flow around the particle, canceling the
effect of stratification and restoring the unstratified Stokes flow.


title: Subjective Reality and Strong Artificial Intelligence

abstract:
  The main prospective aim of modern research related to Artificial
Intelligence is the creation of technical systems that implement the idea of
Strong Intelligence. According our point of view the path to the development of
such systems comes through the research in the field related to perceptions.
Here we formulate the model of the perception of external world which may be
used for the description of perceptual activity of intelligent beings. We
consider a number of issues related to the development of the set of patterns
which will be used by the intelligent system when interacting with environment.
The key idea of the presented perception model is the idea of subjective
reality. The principle of the relativity of perceived world is formulated. It
is shown that this principle is the immediate consequence of the idea of
subjective reality. In this paper we show how the methodology of subjective
reality may be used for the creation of different types of Strong AI systems.


title:
Comparison of P300 Responses in Auditory, Visual and Audiovisual Spatial
  Speller BCI Paradigms

abstract:
  The aim of this study is to provide a comprehensive test of three spatial
speller settings, for the auditory, visual, and audiovisual paradigms. For
rigour, the study is conducted with 16 BCI-na\"ive subjects in an experimental
set-up based on five Japanese hiragana characters. Auditory P300 responses give
encouragingly longer target vs. non-target latencies during the training phase,
however, real-world online BCI experiments in the multimodal setting do not
validate this potential advantage. Our case studies indicate that the auditory
spatial unimodal paradigm needs further development in order to be a viable
alternative to the established visual domain speller applications, as far as
BCI-na\"ive subjects are concerned.


title: On partial $\Pi$-property of subgroups of finite groups

abstract:
  Let $H$ be a subgroup of a finite group $G$. We say that $H$ satisfies
partial $\Pi$-property in $G$ if there exists a chief series
$\mathit{\Gamma}_G:1=G_0<G_1<\cdots<G_n=G$ of $G$ such that for every $G$-chief
factor $G_i/G_{i-1}$ ($1\leq i\leq n$) of $\mathit{\Gamma}_G$,
$|G/G_{i-1}:N_{G/G_{i-1}}(HG_{i-1}/G_{i-1}\cap G_i/G_{i-1})|$ is a
$\pi(HG_{i-1}/G_{i-1}\cap G_i/G_{i-1})$-number. Our main results are listed
here:
  Theorem A. Let $\mathfrak{F}$ be a solubly saturated formation containing
$\mathfrak{U}$ and $E$ a normal subgroup of $G$ with $G/E\in \mathfrak{F}$. Let
$X\unlhd G$ such that $F_p^*(E)\leq X\leq E$. Suppose that for any Sylow
$p$-subgroup $P$ of $X$, every maximal subgroup of $P$ satisfies partial
$\Pi$-property in $G$. Then one of the following holds:
  (1) $G\in \mathfrak{G}_{p'}\mathfrak{F}$.
  (2) $X/O_{p'}(X)$ is a quasisimple group with Sylow $p$-subgroups of order
$p$. In particular, if $X=F_p^*(E)$, then $X/O_{p'}(X)$ is a simple group.
  Theorem B. Let $\mathfrak{F}$ be a solubly saturated formation containing
$\mathfrak{U}$ and $E$ a normal subgroup of $G$ with $G/E\in \mathfrak{F}$.
Suppose that for any Sylow $p$-subgroup $P$ of $F_p^*(E)$, every cyclic
subgroup of $P$ of prime order or order 4 (when $P$ is not quaternion-free)
satisfies partial $\Pi$-property in $G$. Then $G\in
\mathfrak{G}_{p'}\mathfrak{F}$.


title:
Subspace Codes for Random Networks Based on Pl\"{u}cker Coordinates and
  Schubert Cells

abstract:
  The Pl\"{u}cker coordinate description of subspaces has been recently
discussed in the context of constant dimension subspace codes for random
networks, as well as the Schubert cell description of certain code parameters.
In this paper this classical tool is used to reformulate some standard
constructions of constant dimension codes so as to give a unified framework. A
general method of constructing non-constant dimension subspace codes with
respect to a given minimum subspace distance or minimum injection distance
among subspaces is presented. These codes may be described as the union of
constant dimension subspace codes restricted to selected Schubert cells. The
selection of these Schubert cells is based on the subset distance of tuples
corresponding to the Pl\"{u}cker coordinate matrices associated with the
subspaces contained in the respective Schubert cells. In this context, it is
shown that a recent construction of non-constant dimension Ferrers-diagram
rank-metric subspace codes (Khaleghi and Kschischang) is subsumed in the
present framework.


title: Towards An Exact Combinatorial Algorithm for LP Decoding of Turbo Codes

abstract:
  We present a novel algorithm that solves the turbo code LP decoding problem
in a fininte number of steps by Euclidean distance minimizations, which in turn
rely on repeated shortest path computations in the trellis graph representing
the turbo code. Previous attempts to exploit the combinatorial graph structure
only led to algorithms which are either of heuristic nature or do not guarantee
finite convergence. A numerical study shows that our algorithm clearly beats
the running time, up to a factor of 100, of generic commercial LP solvers for
medium-sized codes, especially for high SNR values.


title: A pathwise comparison result for parallel queues

abstract:
  We introduce the appropriate framework for pathwise comparison of multiple
server queues under general stationary ergodic assumptions. We show in what
sense it is better to have more servers for a system under FCFS ('First Come,
First Served') or equivalently, more queues in a system of parallel queues
under the JSW ('Join the Shortest Workload') allocation policy. This comparison
result is based on the recursive representation of Kiefer and Wolfowitz, and on
a non-mass conservative generalization of the Schur-Convex semi-ordering. We
also show that the latter result does not hold true in general, for the larger
class of systems applying the semi-cyclic allocation policy introduced by
Scheller-Wolf in \cite{SW03}.


title: Fixed effects Selection in high dimensional Linear Mixed Models

abstract:
  We consider linear mixed models in which the observations are grouped. A
L1-penalization on the fixed effects coefficients of the log-likelihood
obtained by considering the random effects as missing values is proposed. A
multicycle ECM algorithm is used to solve the optimization problem; it can be
combined with any variable selection method developed for linear models. The
algorithm allows the number of parameters p to be larger than the total number
of observations n; it is faster than the lmmLasso (Schelldorfer,2011) since no
n*n matrix has to be inverted. We show that the theoretical results of
Schelldorfer (2011) apply for our method when the variances of both the random
effects and the residuals are known. The combination of the algorithm with a
variable selection method (Rohart 2011) shows good results in estimating the
set of relevant fixed effects coefficients as well as estimating the variances;
it outperforms the lmmLasso both in the common case (p< n) and in the
high-dimensional case (p > n).


title: Piecewise linear actions and Zimmer's program

abstract:
  We consider Zimmer's program of lattice actions on surfaces by PL
homomorphisms. It is proved that when the surface is not the torus or Klein
bottle the action of any finite-index subgroup of SL(n,Z), n>4, (more generally
for any 2-big lattice), factors through a finite group action. The proof is
based on an establishment of a PL version of Reeb-Thurston's stability.


title:
Spintronic properties and stability of the half-Heusler alloys LiMnZ
  (Z=N, P, Si)

abstract:
  Li-based half-Heusler alloys have attracted much attention due to their
potential applications in optoelectronics and because they carry the
possibility of exhibiting large magnetic moments for spintronic applications.
Due to their similarities to metastable zinc blende half-metals, the
half-Heusler alloys $\beta$-LiMnZ (Z = N, P and Si) were systematically
examined for their electric, magnetic and stability properties at optimized
lattice constants and strained lattice constants that exhibit half-metallic
properties. Other phases of the half-Heusler structure ($\alpha$ and $\gamma$)
are also reported here, but they are unlikely to be grown. The magnetic moments
of these stable Li-based alloys are expected to reach as high as 4
$\mu_{\mathrm{B}}$ per unit cell when Z = Si and 5 $\mu_{\mathrm{B}}$ per unit
cell when Z = N and P, however the antiferromagnetic spin configuration is
energetically favored when Z is a pnictogen. $\beta$-LiMnSi at a lattice
constant 14\% larger than its equilibrium lattice constant is a promising
half-metal for spintronic applications due to its large magnetic moment and
vibrational stability. The modified Slater--Pauling rule for these alloys is
determined. Finally, a plausible method for developing half-metallic Li$_x$MnZ
at equilibrium, by tuning $x$, is investigated, but, unlike tetragonalization,
this type of alloying introduces local structural changes that destroy the
half-metallicity.


title: On non-equilibrium physics and string theory

abstract:
  In this article we review the relation between string theory and
non-equilibrium physics based on our previously published work. First we
explain why a theory of quantum gravity and non-equilibrium statistical physics
should be related in the first place. Then we present the necessary background
from the recent research in non-equilibrium physics. The review discusses the
relationship of string theory and aging phenomena, as well as the connection
between AdS/CFT correspondence and the Jarzynski identity. We also discuss the
emergent symmetries in fully developed turbulence and the corresponding
non-equilibrium stationary states. Finally we outline a larger picture
regarding the relationship between non-perturbative quantum gravity and
non-equilibrium statistical physics. This relationship can be understood as a
natural generalization of the well-known Wilsonian relation between local
quantum field theory and equilibrium statistical physics of critical phenomena.
According to this picture the AdS/CFT duality is just an example of a more
general connection between non-perturbative quantum gravity and non-equilibrium
physics. In the appendix of this review we discuss a new kind of
complementarity between thermodynamics and statistical physics which should be
important in the context of black hole complementarity.


title: Cosmetic crossings of twisted knots

abstract:
  We prove that the property of admitting no cosmetic crossing changes is
preserved under the operation of forming certain satellites of winding number
zero. We also define strongly cosmetic crossing changes and we discuss their
behavior under the operation of inserting full twists in the strings of closed
braids.


title: The rolling problem: overview and challenges

abstract:
  In the present paper we give a historical account -ranging from classical to
modern results- of the problem of rolling two Riemannian manifolds one on the
other, with the restrictions that they cannot instantaneously slip or spin one
with respect to the other. On the way we show how this problem has profited
from the development of intrinsic Riemannian geometry, from geometric control
theory and sub-Riemannian geometry. We also mention how other areas -such as
robotics and interpolation theory- have employed the rolling model.


title:
Shattering Thresholds for Random Systems of Sets, Words, and
  Permutations

abstract:
  This paper considers a problem that relates to the theories of covering
arrays, permutation patterns, Vapnik-Chervonenkis (VC) classes, and probability
thresholds. Specifically, we want to find the number of subsets of
[n]:={1,2,....,n} we need to randomly select, in a certain probability space,
so as to respectively "shatter" all t-subsets of [n]. Moving from subsets to
words, we ask for the number of n-letter words on a q-letter alphabet that are
needed to shatter all t-subwords of the q^n words of length n. Finally, we
explore the number of random permutations of [n] needed to shatter
(specializing to t=3), all length 3 permutation patterns in specified
positions. We uncover a very sharp zero-one probability threshold for the
emergence of such shattering; Talagrand's isoperimetric inequality in product
spaces is used as a key tool.


title: Average Bounds for Kloosterman Sums Over Primes

abstract:
  We prove two estimates for averages of sums of Kloosterman fractions over
primes. The first of these improves previous results of Fouvry-Shparlinski and
Baker.


title:
The Morphologies of Massive Galaxies at 1 < z < 3 in the CANDELS-UDS
  Field

abstract:
  We have used high-resolution, HST WFC3/IR, near-infrared imaging to conduct a
detailed bulge-disk decomposition of the morphologies of ~200 of the most
massive (M_star > 10^11 M_solar) galaxies at 1<z<3 in the CANDELS-UDS field. We
find that, while such massive galaxies at low redshift are generally
bulge-dominated, at redshifts 1<z<2 they are predominantly mixed bulge+disk
systems, and by z>2 they are mostly disk-dominated. Interestingly, we find that
while most of the quiescent galaxies are bulge-dominated, a significant
fraction (25-40%) of the most quiescent galaxies, have disk-dominated
morphologies. Thus, our results suggest that the physical mechanisms which
quench star-formation activity are not simply connected to those responsible
for the morphological transformation of massive galaxies.


title:
Symmetries and optical transitions of hexagonal quantum dots in
  GaAs/AlGaAs nanowires

abstract:
  We investigate the properties of electronic states and optical transitions in
hexagonal GaAs quantum dots within AlGaAs nanowires. Such dots are particularly
interesting due to their high degree of symmetry. A streamlined
postsymmetrization technique based on class operators (PTCO) is developed which
enables one to benefit in one run from the insight brought by the Maximal
symmetrization and reduction of fields (MSRF) approach reported by Dalessi et
al. [Phys. Rev. B 81, 125106 (2010)], after having solved the Schr\"odinger
equation. Definite advantages of the PTCO are that it does not require having
to modify any existing code for the calculation of the electronic structure,
and that it allows to numerically test for elevated symmetries. We show in the
frame of a 4-band k.p model that despite the fact that the D6h symmetry of the
nanostructure is broken at the microscopic level by the underlying Zinc Blende
crystal structure, the effect is quite small. Most of the particularities of
the electronic states and their optical emission can be understood by symmetry
elevation to D6h and the presence of approximate azimuthal and radial quantum
numbers.


title: Increased Network Interdependency Leads to Aging

abstract:
  Although species longevity is subject to a diverse range of selective forces,
the mortality curves of a wide variety of organisms are rather similar. We
argue that aging and its universal characteristics may have evolved by means of
a gradual increase in the systemic interdependence between a large collection
of biochemical or mechanical components. Modeling the organism as a dependency
network which we create using a constructive evolutionary process, we age it by
allowing nodes to be broken or repaired according to a probabilistic algorithm
that accounts for random failures/repairs and dependencies. Our simulations
show that the network slowly accumulates damage and then catastrophically
collapses. We use our simulations to fit experimental data for the time
dependent mortality rates of a variety of multicellular organisms and even
complex machines such as automobiles. Our study suggests that aging is an
emergent finite-size effect in networks with dynamical dependencies and that
the qualitative and quantitative features of aging are not sensitively
dependent on the details of system structure.


title:
On estimating extremal dependence structures by parametric spectral
  measures

abstract:
  Estimation of extreme value copulas is often required in situations where
available data are sparse. Parametric methods may then be the preferred
approach. A possible way of defining parametric families that are simple and,
at the same time, cover a large variety of multivariate extremal dependence
structures is to build models based on spectral measures. This approach is
considered here. Parametric families of spectral measures are defined as convex
hulls of suitable basis elements, and parameters are estimated by projecting an
initial nonparametric estimator on these finite-dimensional spaces. Asymptotic
distributions are derived for the estimated parameters and the resulting
estimates of the spectral measure and the extreme value copula. Finite sample
properties are illustrated by a simulation study.


title: The phase diagram of nuclear and quark matter at high baryon density

abstract:
  We review theoretical approaches to explore the phase diagram of nuclear and
quark matter at high baryon density. We first look over the basic properties of
quantum chromodynamics (QCD) and address how to describe various states of QCD
matter. In our discussions on nuclear matter we cover the relativistic
mean-field model, the chiral perturbation theory, and the approximation based
on the large-Nc limit where Nc is the number of colors. We then explain the
liquid-gas phase transition and the inhomogeneous meson condensation in nuclear
matter with emphasis put on the relevance to quark matter. We commence the next
part focused on quark matter with the bootstrap model and the Hagedorn
temperature. Then we turn to properties associated with chiral symmetry and
exposit theoretical descriptions of the chiral phase transition. There emerge
some quark-matter counterparts of phenomena seen in nuclear matter such as the
liquid-gas phase transition and the inhomogeneous structure of the chiral
condensate. The third regime that is being recognized recently is what is
called quarkyonic matter, which has both aspects of nuclear and quark matter.
We closely elucidate the basic idea of quarkyonic matter in the large-Nc limit
and its physics implications. Finally, we discuss some experimental indications
for the QCD phase diagram and close the review with outlooks.


title: Stability of travelling waves in stochastic Nagumo equations

abstract:
  Stability of travelling waves for the Nagumo equation on the whole line is
proven using a new approach via functional inequalities and an implicitely
defined phase adaption. The approach can be carried over to obtain pathwise
stability of travelling wave solutions in the case of the stochastic Nagumo
equation as well. The noise term considered is of multiplicative type with
variance proportional to the distance of the solution to the orbit of the
travelling wave solutions.


title:
Complete Riemannian $G_2$ Holonomy Metrics on Deformations of Cones over
  $S^3\times S^3$

abstract:
  Complete Riemannian metrics with holonomy group $G_2$ are constructed on the
manifolds obtained by deformations of cones over $S^3 \times S^3$.


title:
Rapidly reconfigurable optically induced photonic crystals in hot
  rubidium vapor

abstract:
  Through periodic index modulation, we create two different types of photonic
structures in a heated rubidium vapor for controlled reflection, transmission
and diffraction of light. The modulation is achieved through the use of the AC
Stark effect resulting from a standing-wave control field. The periodic
intensity structures create translationally invariant index profiles analogous
to photonic crystals in spectral regions of steep dispersion. Experimental
results are consistent with modeling.