title: Enhanced asymptotic symmetry algebra of AdS3

abstract:
  A generalization of the Brown-Henneaux boundary conditions is introduced for
pure gravity with negative cosmological constant in 3 dimensions. This leads to
new degrees of freedom and to an enhancement of the symmetry algebra. Up to the
zero modes, it consists of two copies of the semi-direct product of a Virasoro
algebra with a U(1) current algebra. The associated surface charge algebra now
contains three non-zero central charges: the two usual Brown-Henneaux central
charges and one new quantity.


title:
What Does the CMS Measurement of W-polarization Tell Us about the
  Underlying Theory of the Coupling of W-Bosons to Matter?

abstract:
  We discuss results of the CMS collaboration on the sensitivity of the LHC to
$W$ boson polarisation in the process $pp\to W^\pm + jet \to e^\pm
jet+\not\!\!P_T$ using the $L_P$ variable directly connected to $\theta^*$
angle of the outgoing lepton in the rest frame of the decaying $W$. We have
shown that for a given $L_P$, interference between different polarizations of
the $W$-boson is not negligible, and needs to be taken into account when
considering the differential cross-section with respect to $L_P$. The $L_P$
variable suggested by CMS collaboration is highly suitable variable to study
LHC sensitivity to $g_V,g_A$ couplings of $W$-boson to fermions. We note that
the experimental sensitivity to W-boson polarization which is much higher than
that to ($g_V,g_A$) parameter space can be turned around and used to identify
deviations from the Standard Model as a signal for new physics at the LHC.


title: Nonlinear stationary states in PT-symmetric lattices

abstract:
  In the present work we examine both the linear and nonlinear properties of
two related PT-symmetric systems of the discrete nonlinear Schrodinger (dNLS)
type.
  First, we examine the parameter range for which the finite PT-dNLS chains
have real eigenvalues and PT-symmetric linear eigenstates. We develop a
systematic way of analyzing the nonlinear stationary states with the implicit
function theorem at an analogue of the anti-continuum limit for the dNLS
equation.
  Secondly, we consider the case when a finite PT-dNLS chain is embedded as a
defect in the infinite dNLS lattice. We show that the stability intervals of
the infinite PT-dNLS lattice are wider than in the case of a finite PT-dNLS
chain. We also prove existence of localized stationary states (discrete
solitons) in the analogue of the anti-continuum limit for the dNLS equation.
  Numerical computations illustrate the existence of nonlinear stationary
states, as well as the stability and saddle-center bifurcations of discrete
solitons.


title:
The Role of Magnetic Fields in Transient Seismic Emission Driven by
  Atmospheric Heating in Flares

abstract:
  The physics of transient seismic emission in flares remains largely
mysterious. Its discoverers proposed that these "sunquakes" are the signature
of a shock driven by "thick-target heating" of the flaring chromosphere.
H-{\alpha} observations show evidence for such a shock. However, simulations of
shocks driven by impulsive chromospheric heating show withering radiative
losses as the shock proceeds downward. The compression of the shocked gas heats
and increases its density, making it more radiative. So, radiative losses
increase radically with the strength of the shock. This has introduced doubt
that sufficient energy from such a shock can penetrate into the solar interior
to match that indicated by the helioseismic signatures. We point out that
simulations of acoustic transients driven by impulsive heating have no account
for magnetic fields characteristic of transient-seismic-source environments.
These must have a major impact on the seismic flux conducted into the solar
interior. A strong horizontal magnetic field, for example, greatly increases
the compressional modulus of the chromospheric medium. This greatly reduces
compression of the gas, hence the radiative losses as the transient passes
through it. This could explain the strong affinity of seismic sources to
regions of strong, highly inclined penumbral magnetic fields. The role of
inclined magnetic fields, then, is fundamental to our understanding of the role
of impulsive heating in transient seismic emission.


title: Optical thickness determination of hexagonal Boron Nitride flakes

abstract:
  Optical reflectivity contrast provides a simple, fast and noninvasive method
for characterization of few monolayer samples of two-dimensional materials.
Here we apply this technique to measure the thickness of thin flakes of
hexagonal Boron Nitride (hBN), which is a material of increasing interest in
nanodevice fabrication. The optical contrast shows a strong negative peak at
short wavelengths and zero contrast at a thickness dependent wavelength. The
optical contrast varies linearly for 1-80 layers of hBN, which permits easy
calibration of thickness. We demonstrate the applicability of this quick
characterization method by comparing atomic force microscopy and optical
contrast results.


title:
Effective vanishing theorems for ample and globally generated vector
  bundles

abstract:
  By proving an integral formula of the curvature tensor of $E\ts \det E$, we
observe that the curvature tensor of $E\ts \det E$ is very similar to that of a
line bundle and obtain certain new Kodaira-Akizuki-Nakano type vanishing
theorems for vector bundles. As special cases, we deduce vanishing theorems for
ample, nef and globally generated vector bundles by analytic method instead of
the Leray-Borel-Le Potier spectral sequence.


title: Cosmology with the 6-degree Field Galaxy Survey

abstract:
  This thesis presents the analysis of the clustering of galaxies in the 6dF
Galaxy Survey (6dFGS). At large separation scales the baryon acoustic
oscillation (BAO) signal is detected which allows to make an absolute distance
measurement at $z_{\rm eff} = 0.106$. Such a measurement can be used to
constrain the Hubble constant, $H_0 = 67.0\pm3.2\;$km s$^{-1}\;$Mpc$^{-1}$
(4.8% precision).
  Modelling the 2D galaxy correlation function of 6dFGS, $\xi(r_p,\pi)$, allows
a measure of the parameter combination $f(z_{\rm eff})\sigma_8(z_{\rm eff}) =
0.423 \pm 0.055$, where $f \simeq \Omega_m^{\gamma}(z)$ is the growth rate of
cosmic structure and $\sigma_8$ is the r.m.s. of matter fluctuations in
$8h^{-1}\,$Mpc spheres. Such a measurement allows to test the relationship
between matter and gravity on cosmic scales by constraining the growth index of
density fluctuations, $\gamma$. The 6dFGS measurement of $f\sigma_8$ combined
with WMAP-7, results in $\gamma = 0.547 \pm 0.088$, consistent with the
prediction of General Relativity ($\gamma_{\rm GR} \approx 0.55$).
  The last chapter of this thesis studies the stellar-mass dependence of galaxy
clustering in the 6dF Galaxy Survey. Using the Halo Occupation Distribution
(HOD) model, this analysis investigates the trend of dark matter halo mass and
satellite fraction with stellar mass by measuring the projected correlation
function, $w_p(r_p)$. The findings of this analysis are, that the typical halo
mass ($M_1$) as well as the satellite power law index ($\alpha$) increase with
stellar mass. The 6dFGS results are compared to two different semi-analytic
models derived from the Millennium Simulation, as well as weak lensing
measurements.


title: The Khovanov homology of 3-strand pretzels, revisited

abstract:
  We compute the reduced Khovanov homology of 3-stranded pretzel links. The
coefficients are the integers with the "even" sign assignment. In particular,
we show that the only homologically thin, non-quasi-alternating 3-stranded
pretzels are P(-p,p,r) with p an odd integer and r greater than or equal to p
(these were shown to be homologically thin by Starkston and Qazaqzeh).


title:
Majorana Fermions in superconducting wires: effects of long-range
  hopping, broken time-reversal symmetry and potential landscapes

abstract:
  We present a comprehensive study of two of the most experimentally relevant
extensions of Kitaev's spinless model of a 1D p-wave superconductor: those
involving (i) longer range hopping and superconductivity and (ii) inhomogeneous
potentials. We commence with a pedagogical review of the spinless model and, as
a means of characterizing topological phases exhibited by the systems studied
here, we introduce bulk topological invariants as well as those derived from an
explicit consideration of boundary modes. In time-reversal invariant systems,
we find that the longer range hopping leads to topological phases characterized
by multiple Majorana modes. In particular, we investigate a spin model, which
respects a duality and maps to a fermionic model with multiple Majorana modes;
we highlight the connection between these topological phases and the broken
symmetry phases in the original spin model. In the presence of time-reversal
symmetry breaking terms, we show that the topological phase diagram is
characterized by an extended gapless regime. For the case of inhomogeneous
potentials, we explore phase diagrams of periodic, quasiperiodic, and
disordered systems. We present a detailed mapping between normal state
localization properties of such systems and the topological phases of the
corresponding superconducting systems. This powerful tool allows us to leverage
the analyses of Hofstadter's butterfly and the vast literature on Anderson
localization to the question of Majorana modes in superconducting quasiperiodic
and disordered systems, respectively. We briefly touch upon the synergistic
effects that can be expected in cases where long-range hopping and disorder are
both present.


title:
On boundary H\"older gradient estimates for solutions to the linearized
  Monge-Amp\`ere equations

abstract:
  In this paper, we establish boundary H\"older gradient estimates for
solutions to the linearized Monge-Amp\`ere equations with $L^{p}$
($n<p\leq\infty$) right hand side and $C^{1,\gamma}$ boundary values under
natural assumptions on the domain, boundary data and the Monge-Amp\`ere
measure. These estimates extend our previous boundary regularity results for
solutions to the linearized Monge-Amp\`ere equations with bounded right hand
side and $C^{1, 1}$ boundary data.


title:
An embedded measurement system for electrical characterization of EGFET
  as pH sensor

abstract:
  This work presents the development of an electronic system for the electrical
characterization of pH sensors based on the extended gate field effect
transistor (EGFET). We designed an electronic circuit with a microcontroller
(PIC15F14K50) as the main component in order to provide two programmable
outputs voltage as well as circuits to measure electric current and voltages.
The instrument performance analyze was carried out using a glass electrode as a
sensitive membrane for investigating the EGFET operation as pH sensor. The
results show that the system is an alternative to commercial equipment for the
electrical characterization of sensors based on field effect devices. In
addition, some of the key features expected of this electronic module are: low
cost, flexibility, portability and communication with a personal computer using
a USB port.


title: Cosmography with the Sunyaev-Zeldovich effect and X-ray data

abstract:
  Cosmography provides a direct method to map the expansion history of the
Universe in a model-independent way. Recently, different kinds of observations
have been used in cosmographic analyses, such as SNe Ia and gamma ray bursts
measurements, weak and strong lensing, cosmic microwave background
anisotropies, etc. In this work we examine the prospects for constraining
cosmographic parameters from current and future measurements of galaxy clusters
distances based on their Sunyaev-Zeldovich effect (SZE) and X-ray observations.
By assuming the current observational error distribution, we perform Monte
Carlo simulations based on a well-behaved parameterization for the deceleration
parameter to generate samples with different characteristics and study the
improvement on the determination of the cosmographic parameters from upcoming
data. The influence of galaxy clusters (GC) morphologies on the $H_0- q_0$
plane is also investigated.


title:
A Ni-Fe Layered Double Hydroxide-Carbon Nanotube Complex for Water
  Oxidation

abstract:
  Highly active, durable and cost-effective electrocatalysts for water
oxidation to evolve oxygen gas hold a key to a range of renewable energy
solutions including water splitting and rechargeable metal-air batteries. Here,
we report the synthesis of ultrathin nickel iron layered double hydroxide
nanoplates on mildly oxidized multi-walled carbon nanotubes. Incorporation of
Fe into the nickel hydroxide induced the formation of NiFe-layered double
hydroxide. The nanoplates were covalently attached to a network of nanotubes,
affording excellent electrical wiring to the nanoplates. The ultra-thin Ni-Fe
layered double hydroxide nanoplates/carbon nanotube complex was found to
exhibit unusually high electro-catalytic activity and stability for oxygen
evolution and outperformed commercial precious metal Ir catalysts.


title: Sharp local smoothing for manifolds with smooth inflection transmission

abstract:
  We consider a family of spherically symmetric, asymptotically Euclidean
manifolds with two trapped sets, one which is unstable and one which is
semi-stable. The phase space structure is that of an inflection transmission
set. We prove a sharp local smoothing estimate for the linear Schr\"odinger
equation with a loss which depends on how flat the manifold is near each of the
trapped sets. The result interpolates between the family of similar estimates
in \cite{ChWu-lsm}. As a consequence of the techniques of proof, we also show a
sharp high energy resolvent estimate with a polynomial loss depending on how
flat the manifold is near each of the trapped sets.


title: The John-Nirenberg inequality with sharp constants

abstract:
  We consider the one-dimensional John-Nirenberg inequality: $$ |\{x\in
I_0:|f(x)-f_{I_0}|>\a\}|\le C_1|I_0|\exp\Big(-\frac{C_2}{\|f\|_{*}}\a\Big). $$
A. Korenovskii found that the sharp $C_2$ here is $C_2=2/e$. It is shown in
this paper that if $C_2=2/e$, then the best possible $C_1$ is $C_1=
\frac{1}{2}e^{4/e}$.


title:
The Hopf automorphism group and the quantum Brauer group in braided
  monoidal categories

abstract:
  With the motivation of giving a more precise estimation of the quantum Brauer
group of a Hopf algebra $H$ over a field $k$ we construct an exact sequence
containing the quantum Brauer group of a Hopf algebra in a certain braided
monoidal category. Let $B$ be a Hopf algebra in $\C=_H ^H\YD$, the category of
Yetter-Drinfel'd modules over $H$. We consider the quantum Brauer group
$\BQ(\C; B)$ of $B$ in $\C$, which is isomorphic to the usual quantum Brauer
group $\BQ(k; B\rtimes H)$ of the Radford biproduct Hopf algebra $B\rtimes H$.
We show that under certain symmetricity condition on the braiding in $\C$ there
is an inner action of the Hopf automorphism group of $B$ on the former. We
prove that the subgroup $\BM(\C; B)$ - the Brauer group of module algebras over
$B$ in $\C$ - is invariant under this action for a family of Radford biproduct
Hopf algebras. The analogous invariance we study for $\BM(k; B\rtimes H)$. We
apply our recent results on the latter group and generate a new subgroup of the
quantum Brauer group of $B\rtimes H$. In particular, we get new information on
the quantum Brauer groups of some known Hopf algebras.


title: UV/Optical/IR Color Sequences Along the Tidal Ring/Arm of Arp 107

abstract:
  We construct UV/optical/IR spectral energy distributions for 29 star forming
regions in the interacting galaxy Arp 107, using GALEX UV, Sloan Digitized Sky
Survey optical, and Spitzer infrared images. In an earlier study utilizing only
the Spitzer data, we found a sequence in the mid-infrared colors of
star-forming knots along the strong tidal arm in this system. In the current
study, we find sequences in the UV/optical colors along the tidal arm that
mirror those in the mid-infrared, with blue UV/optical colors found for regions
that are red in the mid-infrared, and vice versa. With single-burst stellar
population synthesis models, we find a sequence in the average stellar age
along this arm, with younger stars preferentially located further out in the
arm. Models that allow two populations of different ages and dust attenuations
suggest that there may be both a young component and an older population
present in these regions. Thus the observed color sequences may be better
interpreted as a sequence in the relative proportion of young and old stars
along the arm, with a larger fraction of young stars near the end. Comparison
with star forming regions in other interacting galaxies shows that the Arp 107
regions are relatively quiescent, with less intense star formation than in many
other systems.


title: Radio emission from Air Showers. Comparison of theoretical approaches

abstract:
  While the fluorescence and the ground counter techniques for the detection of
ultra-high energy cosmic rays (UHECR) were being developed for decades, the
interest in the radio detection diminished after the initial experiments in the
1960s. As a result, the fluorescence and the surface array techniques are more
mature today, providing more reliable measurements of the primary cosmic
particle energy, chemical composition and the inelastic cross-section. The
advantages of the radio technique are 100 percent duty cycle and lower
deployment and operational costs. Thus, the radio technique can greatly
complement the fluorescence and the ground array detection and can also work
independently. With the ANITA balloon detector observing UHECRs and the success
of LOPES, CODALEMA and other surface radio detectors, the radio technique
received a significant boost in recent years. Reliable Monte Carlo (MC)
simulations are needed in order to obtain the energy and other parameters of
the primary cosmic ray particle from the radio observations. Several MC
techniques, like ZHairesS and the Endpoint Formalism, were proposed in recent
years. While they seem to reproduce some of the observed data quite well, there
is a divergence between the different approaches under certain conditions. In
this work we derive these approaches from Maxwells equations and prove their
identity under certain conditions as well as discuss their applicability to the
UHECR air showers and to a proposed experiment at SLAC.


title: Eigenvalues of Toeplitz Operators on the Annulus and Neil Algebra

abstract:
  By working with all collection of all the Sarason Hilbert Hardy spaces for
the annulus algebra an improvement to the results of Aryana and Clancey on
eigenvalues of self adjoint Toeplitz operators on an annulus is obtained. The
ideas are applied to Toeplitz operators on the Neil algebra. These examples may
provide a template for a general theory of Toeplitz operators with respect to
an algebra.


title: Skorokhod Embeddings via Stochastic Flows on the Space of Measures

abstract:
  We present a new construction of a Skorohod embedding, namely, given a
probability measure mu with zero expectation and finite variance, we construct
an integrable stopping time T adapted to a filtration F_t, such that W_t has
the law mu, where W_t is a standard Wiener process adapted to the same
filtration. We find several sufficient conditions for the stopping time T to be
bounded or to have a sub-exponential tail. In particular, our embedding seems
rather natural for the case that mu is a log-concave measure and the tail
behaviour of $T$ admits some tight bounds in that case. Our embedding admits
the property that the stochastic measure-valued process {mu_t} (0<t<T), where
mu_t is as the law of W_T conditioned on F_t, is a Markov process.


title:
Valley-Spin Polarization in the Magneto-Optical Response of Silicene and
  Other Similar 2D Crystals

abstract:
  We calculate the magneto-optical conductivity and electronic density of
states for silicene, the silicon equivalent of graphene, and similar crystals
such as germanene. In the presence of a perpendicular magnetic field and
electric field gating, we note that four spin- and valley-polarized levels can
be seen in the density of states and transitions between these levels lead to
similarly polarized absorption lines in the longitudinal, transverse Hall, and
circularly polarized dynamic conductivity. While previous spin and
valley-polarization predicted for the conductivity is only present in the
response to circularly polarized light, we show that distinct spin- and
valley-polarization can also be seen in the longitudinal magneto-optical
conductivity at experimentally attainable energies. The frequency of the
absorption lines may be tuned by the electric and magnetic field to onset in a
range varying from THz to the infrared. This potential to isolate charge
carriers of definite spin and valley label may make silicene a promising
candidate for spin- and valleytronic devices.


title: On \alpha' corrections in N=1 F-theory compactifications

abstract:
  We consider N=1 F-theory and Type IIB orientifold compactifications and
derive new \alpha' corrections to the four-dimensional effective action. They
originate from higher derivative corrections to eleven-dimensional supergravity
and survive the M-theory to F-theory limit. We find a correction to the Kahler
moduli depending on a non-trivial intersection curve of seven-branes. We also
analyze a four-dimensional higher curvature correction.


title:
Off-shell D-Brane/F-Theory Effective Superpotentials and Ooguri-Vafa
  Invariants of Several Compact Calabi-Yau Manifolds

abstract:
  According to the generalized GKZ system for CY manifold with brane and the
open-closed Mirror map, We calculate the off-shell D-Brane/F-Theory effective
superpotentials and Ooguri-Vafa invariants of several compact Calabi-Yau
manifolds .


title:
A new type of judgement theorems for attribute characters in information
  system

abstract:
  The research of attribute characters in information system which contains
core, necessary, unnecessary is a basic and important issue in attribute
reduct. Many methods for the judgement of attribute characters are based on the
relationship between the objects and attributes. In this paper, a new type of
judgement theorems which are absolutely based on the relationship among
attributes is proposed for the judgement of attribute characters. The method is
through comparing the two new attribute sets $E(a)$ and $N(a)$ with respect to
the designated attribute $a$ which is proposed in this paper. We conclude that
which type of the attribute $a$ belongs to is determined by the relationship
between $E(a)$ and $N(a)$ in essence. Secondly, more concise and clear results
are given about the judgment of the attribute characters through analyzing the
properties of refinement and precise-refinement between $E(a)$ and $N(a)$ in
topology. In addition, the relationship among attributes are discussed which is
useful for constructing a reduct in the last section of this paper. In the
last, we propose a reduct algorithm based on $E(a)$, and this algorithm is an
extended application of the analysis of attribute characters above.


title:
On the preservation of commutation and anticommutation relations of
  N-level quantum systems

abstract:
  The goal of this paper is to provide conditions under which a quantum
stochastic differential equation (QSDE) preserves the commutation and
anticommutation relations of the SU(n) algebra, and thus describes the
evolution of an open n-level quantum system. One of the challenges in the
approach lies in the handling of the so-called anomaly coefficients of SU(n).
Then, it is shown that the physical realizability conditions recently developed
by the authors for open n-level quantum systems also imply preservation of
commutation and anticommutation relations.


title:
Plasmoid Ejections and Loop Contractions in an Eruptive M7.7 Solar
  Flare: Evidence of Particle Acceleration and Heating in Magnetic Reconnection
  Outflows

abstract:
  Where particle acceleration and plasma heating take place in relation to
magnetic reconnection is a fundamental question for solar flares. We report
analysis of an M7.7 flare on 2012 July 19 observed by SDO/AIA and RHESSI.
Bi-directional outflows in forms of plasmoid ejections and contracting
cusp-shaped loops originate between an erupting flux rope and underlying flare
loops at speeds of typically 200-300 km/s up to 1050 km/s. These outflows are
associated with spatially separated double coronal X-ray sources with centroid
separation decreasing with energy. The highest temperature is located near the
nonthermal X-ray loop-top source well below the original heights of contracting
cusps near the inferred reconnection site. These observations suggest that the
primary loci of particle acceleration and plasma heating are in the
reconnection outflow regions, rather than the reconnection site itself. In
addition, there is an initial ascent of the X-ray and EUV loop-top source prior
to its recently recognized descent, which we ascribe to the interplay among
multiple processes including the upward development of reconnection and the
downward contractions of reconnected loops. The impulsive phase onset is
delayed by 10 minutes from the start of the descent, but coincides with the
rapid speed increases of the upward plasmoids, the individual loop shrinkages,
and the overall loop-top descent, suggestive of an intimate relation of the
energy release rate and reconnection outflow speed.

categories: astro-ph.SR astro-ph.HE physics.plasm-ph physics.space-ph


title:
Temperature dependent electronic structures and the negative thermal
  expansion of \delta -Pu

abstract:
  We introduce a temperature-dependent parameterization in the modified
embedded-atom method and combine it with molecular dynamics to simulate the
diverse physical properties of the \delta - and \epsilon - phases of elemental
plutonium. The aim of this temperature-dependent parameterization is to mimic
the different magnitudes of correlation strength of the Pu 5f electrons at
different temperatures. Compared to previous temperature independent
parameterization, our approach captures the negative thermal expansion and
temperature dependence of the bulk moduli in the \delta -phase. We trace this
improvement to a strong softening of phonons near the zone boundary and an
increase of the f-like partial density and anharmonic effects induced by the
temperature-dependent parameterization upon increasing temperature. Our study
suggests it is important to include temperature-dependent parameterization in
classical force field methods to simulate complex materials such as Pu.


title: Universal Cycles of Complementary Classes

abstract:
  Universal Cycles, or U-cycles, as originally defined by de Bruijn, are an
efficient method to exhibit a large class of combinatorial objects in a
compressed fashion, and with no repeats. de Bruijn's theorem states that
U-cycles for $n$ letter words on a $k$ letter alphabet exist for all $k$ and
$n$. Much has already been proved about Universal Cycles for a variety of other
objects. This work is intended to augment the current research in the area by
exhibiting U-cycles for {\it complementary classes}. Results will be presented
that exhibit the existence of U-cycles for class-alternating words such as
alternating vowel-consonant (VCVC) words; words with at least one repeated
letter (non-injective functions); words with at least one letter of the
alphabet missing (functions that are not onto); words that represent illegal
tournament rankings; and words that do not constitute "strong" legal computer
passwords. As with previous papers pertaining to U-cycles, connectedness proves
to be a nontrivial step.


title:
Electronic Structures and Phonon Spectra in Boronitride Superconductors
  LaMBN (M= Ni, Pt)

abstract:
  We have investigated electronic structures and phonon spectra of newly
discovered isostructural superconductors LaNiBN (T_c = 4.1 K) and LaPtBN (T_c =
6.7 K). We have found that their electronic structures are substantially
three-dimensional, leading to metallicity both in NiB (PtB) and the intervening
LaN layers. Our ab initio phonon calculations show that almost all phonon modes
contribute to the electron-phonon coupling (EPC) mechanism, reflecting that
both layers are involved in the superconductivity. For LaNiBN, we obtain an EPC
strength of \lambda = 0.52 and a logarithmically averaged characteristic phonon
frequency of \omega_{log} = 376 K, leading to T_c = 3.9 K. Compared with the Ni
B_{1g} mode in LaNiBN, the Pt B_{1g} mode in LaPtBN is reduced by ~70%, leading
to a slightly enhanced \lambda = 0.56 and an ~20 % reduced \omega_{log}. The
estimated T_c is 5.4 K for LaPtBN, in good agreement with the experiment. We do
not find any indication of magnetic instability for either LaNiBN or LaPtBN,
which implies that both systems are EPC mediated superconductors. Further, we
have found an interesting trend of monotonic increase of T_c with respect to
the boron height in the NiB (PtB) layer of both borocarbide and boronitride
superconductors, which suggests a possible way to enhance T_c in these systems.


title: Low-Damage High-Throughput Grazing-Angle Sputter Deposition on Graphene

abstract:
  Despite the prevalence of sputter deposition in the microelectronics
industry, it has seen very limited applications for graphene electronics. In
this letter, we report systematic investigation of the sputtering induced
damages in graphene and identify the energetic sputtering gas neutrals as the
primary cause of graphene disorder. We further demonstrate a grazing-incidence
sputtering configuration that strongly suppresses fast neutral bombardment and
retains graphene structure integrity, creating considerably lower damage than
electron-beam evaporation. Such sputtering technique yields fully covered,
smooth thin dielectric films, highlighting its potential for contact metals,
gate oxides, and tunnel barriers fabrication in graphene device applications.


title:
Fabrication and Investigation of Nitrogen doped Ultra-Nano-Crystalline
  Diamond Hall-bar Devices

abstract:
  Using microwave-assisted plasma chemical vapour deposition (CVD) a layer of
Nitrogen doped ultra-nano-crystalline diamond (N-UNCD) is deposited on top of a
non-conducting diamond layer, which itself is situated on a Silicon wafer. This
structure is then shaped into Hall-bar devices of various dimensions using
optical lithography and dry-etching techniques. The devices' electrical
properties are investigated at various temperatures using a cryogen-free
dilution refrigerator.


title:
Rainbow Ramsey theorem for triples is strictly weaker than the
  Arithmetic Comprehension Axiom

abstract:
  We prove that $\RCA + \RRT^3_2 \not\vdash \ACA$ where $\RRT^3_2$ is the
Rainbow Ramsey Theorem for 2-bounded colorings of triples. This reverse
mathematical result is based on a cone avoidance theorem, that every 2-bounded
coloring of pairs admits a cone-avoiding infinite rainbow, regardless of the
complexity of the given coloring. We also apply the proof of the cone avoidance
theorem to the question whether $\RCA + \RRT^4_2 \vdash \ACA$ and obtain some
partial answer.


title: Homotopy groups and periodic geodesics of closed 4-manifolds

abstract:
  Given a simply connected, closed four manifold, we associate to it a simply
connected, closed, spin five manifold. This leads to several consequences : the
stable and unstable homotopy groups of such a four manifold is determined by
its second Betti number, and the ranks of the homotopy groups can be explicitly
calculated. We show that for a generic metric on such a smooth four manifold
with second Betti number at least three, the number of geometrically distinct
periodic geodesics of length at most l grow exponentially as a function of l.
The number of closed Reeb orbits of length at most l on the spherization of the
cotangent bundle also grow exponentially for any Reeb flow.


title: Cohesive sets and rainbows

abstract:
  We study the strength of $\RRT^3_2$, Rainbow Ramsey Theorem for colorings of
triples, and prove that $\RCA + \RRT^3_2$ implies neither $\WKL$ nor
$\RRT^4_2$. To this end, we establish some recursion theoretic properties of
cohesive sets and rainbows for colorings of pairs. We show that every sequence
(2-bounded coloring of pairs) admits a cohesive set (infinite rainbow) of
non-PA Turing degree; and that every $\emptyset'$-recursive sequence (2-bounded
coloring of pairs) admits a $\low_3$ cohesive set (infinite rainbow).


title: VSTAR Modelling of the Infrared Spectrum of Uranus

abstract:
  We modelled the H-band spectrum obtained with the Infrared Imaging
Spectrograph (IRIS2) at the Anglo-Australian Telescope in order to infer the
cloud structure and composition of the atmosphere of the planet between 0.1 and
11 bar. Such modelling can be used to derive the D/H ratio in the atmosphere of
Uranus, which is an important diagnostic of the conditions in early history of
the planetary formation. We describe here our modelling technique based on the
Versatile Software for Transfer of Atmospheric Radiation (VSTAR) (Bailey2012a).
Since the infrared spectrum of Uranus is dominated by absorption from methane,
the accuracy of the models is limited largely by the quality of the low
temperature, methane line databases used. Our modelling includes the latest
laboratory line data for methane described in Bailey (2011). The parameters of
this model will be applied in the future to model our observations of GNIRS
high resolution spectra of Uranus and derive the D/H ratio in the 1.58 micron
window based on absorption in the deuterated methane band in this region.


title: Some logically weak Ramseyan theorems

abstract:
  We study four families of consequences of Ramsey's Theorem from the viewpoint
of reverse mathematics. The first, which we call the Achromatic Ramsey Theorem,
is from a partition relation introduced by Erd\H{o}s, Hajnal and Rado: $\omega
\to [\omega]^r_{c,\leq d}$, which asserts that for every $f: [\omega]^r \to c$
there exists an infinite $H$ with $|f([H]^r)| \leq d$. The second and third are
the Free Set Theorem and the Thin Set Theorem, which were introduced by Harvey
Friedman. And the last is the Rainbow Ramsey Theorem. We show that, most
theorems from these families are quite weak, i.e., they are strictly weaker
than $\operatorname{ACA}_0$ over $\operatorname{RCA}_0$. Interestingly, these
families turn out to be closely related. We establish the so-called strong cone
avoidance property of most instances of the Achromatic Ramsey Theorem by an
induction of exponents, then apply this and a similar induction to obtain the
strong cone avoidance property of the Free Set Theorem. From the strong cone
avoidance property of the Achromatic Ramsey Theorem and the Free Set Theorem,
we derive the strong cone property of the Thin Set Theorem and the Rainbow
Ramsey Theorem. It follws easily that a theorem with the strong cone avoidance
property does not imply $\operatorname{ACA}_0$ over $\operatorname{RCA}_0$.


title:
CruzDB: software for annotation of genomic intervals with UCSC
  genome-browser data

abstract:
  The biological significance of genomic features is often context-dependent.
We present CruzDB, a fast and intuitive programmatic interface to the UCSC
genome browser that facilitates integrative analyses of diverse local and
remotely hosted datasets. We showcase the syntax of CruzDB using miRNA-binding
sites as examples, and further demonstrate its utility with 3 novel biological
discoveries. First, we find that while exons replicate early, introns tend to
replicate late, suggesting a complex replication pattern in gene regions.
Second, variants associated with cognitive functions map to lincRNA transcripts
of relevant function. Third, lamina-associated domains are highly enriched in
olfaction-related genes. CruzDB is available at
https://github.com/brentp/cruzdb


title:
Enhanced Nitrogen in Morphologically Disturbed Blue Compact Galaxies at
  0.20 < z < 0.35: Probing Galaxy Merging Features

abstract:
  We present a study of correlations between the elemental abundances and
galaxy morphologies of 91 blue compact galaxies (BCGs) at z=0.20-0.35 with
Sloan Digital Sky Survey (SDSS) DR7 data. We classify the morphologies of the
galaxies as either 'disturbed' or 'undisturbed', by visual inspection of the
SDSS images, and using the Gini coefficient and M_20. We derive oxygen and
nitrogen abundances using the T_e method. We find that a substantial fraction
of BCGs with disturbed morphologies, indicative of merger remnants, show
relatively high N/O and low O/H abundance ratios. The majority of the disturbed
BCGs exhibit higher N/O values at a given O/H value compared to the
morphologically undisturbed galaxies, implying more efficient nitrogen
enrichment in disturbed BCGs. We detect Wolf-Rayet (WR) features in only a
handful of the disturbed BCGs, which appears to contradict the idea that WR
stars are responsible for high nitrogen abundance. Combining these results with
Galaxy Evolution Explorer (GALEX) GR6 ultraviolet (UV) data, we find that the
majority of the disturbed BCGs show systematically lower values of the H alpha
to near-UV star formation rate ratio. The equivalent width of the H beta
emission line is also systematically lower in the disturbed BCGs. Based on
these results, we infer that disturbed BCGs have undergone star formation over
relatively longer time scales, resulting in a more continuous enrichment of
nitrogen. We suggest that this correlation between morphology and chemical
abundances in BCGs is due to a difference in their recent star formation
histories.


title:
A Monte Carlo study to check the hadronic interaction models by a new
  EAS hybrid experiment in Tibet

abstract:
  A new EAS hybrid experiment has been designed by constructing a YAC
(Yangbajing Air shower Core) detector array inside the existing Tibet-III air
shower array. The first step of YAC, called "YAC-I", consists of 16 plastic
scintillator units (4 rows times 4 columns) each with an area of 40 cm * 50 cm
which is used to check hadronic interaction models used in AS simulations. A
Monte Carlo study shows that YAC-I can record high energy electromagnetic
component in the core region of air showers induced by primary particles of
several tens TeV energies where the primary composition is directly measured by
space experiments. It may provide a direct check of the hadronic interaction
models currently used in the air shower simulations in the corresponding energy
region. In present paper, the method of the observation and the sensitivity of
the characteristics of the observed events to the different interaction models
are discussed.


title: Near geodesics in John domains in Banach spaces

abstract:
  Let $E$ be a real Banach space with dimension at least 2. In this paper, we
prove that if $D\subset E$ is a John domain which is homeomorphic to an inner
uniform domain via a CQH map, then each neargeodesic in $D$ is a cone arc.


title: Observing Strategies for the Detection of Jupiter Analogs

abstract:
  To understand the frequency, and thus the formation and evolution, of
planetary systems like our own solar system, it is critical to detect
Jupiter-like planets in Jupiter-like orbits. For long-term radial-velocity
monitoring, it is useful to estimate the observational effort required to
reliably detect such objects, particularly in light of severe competition for
limited telescope time. We perform detailed simulations of observational
campaigns, maximizing the realism of the sampling of a set of simulated
observations. We then compute the detection limits for each campaign to
quantify the effect of increasing the number of observational epochs and
varying their time coverage. We show that once there is sufficient time
baseline to detect a given orbital period, it becomes less effective to add
further time coverage -- rather, the detectability of a planet scales roughly
as the square root of the number of observations, independently of the number
of orbital cycles included in the data string. We also show that no noise floor
is reached, with a continuing improvement in detectability at the maximum
number of observations N=500 tested here.


title: On Deformations of Pasting Diagrams, II

abstract:
  We continue the development of the infinitesimal deformation theory of
pasting diagrams of k-linear categories begun in Yetter, D.N. "On Deformations
of Pasting Diagrams", Theory and Applications of Categories 22 (2009) 24-53. In
that paper, the standard result that all obstructions are cocycles was
established only for the elementary, composition-free parts of pasting
diagrams. In the present work we give a proof for pasting diagrams in general.
As tools we use (1) the method developed by Shrestha, in his Kansas State
University doctoral dissertation, of representing formulas for obstructions,
along with the corresponding cocycle and cobounding conditions by suitably
labeled polygons, giving a rigorous exposition of the previously heuristic
method, and (2) deformations of pasting diagrams in which some cells are
required to be deformed trivially.


title:
On the effect of secondary protons on baryon and proton number cumulants
  in event-by-event analysis

abstract:
  We investigate the effects of secondary (knockout) protons, which constitute
about 20% of the observed protons at STAR, on the higher order cumulants of
proton and baryon numbers measured by event-by-event analyses in relativistic
heavy ion collisions. We argue that the contribution of this background effect
on the cumulants is expressed by a simple formula, and that hence their effects
can be removed in the experimental analysis. It is discussed that this
background effect has non-negligible contribution to recently observed proton
number cumulants at STAR, especially the third-order one, and that the removal
of this effect is crucial to investigate the thermodynamical properties of the
primordial hot medium appropriately.


title:
The HIFI spectral survey of AFGL2591 (CHESS). I. Highly excited linear
  rotor molecules in the high-mass protostellar envelope

abstract:
  We aim to reveal the gas energetics in the circumstellar environment of the
prototypical high-mass protostellar object AFGL2591 using space-based
far-infrared observations of linear rotor molecules.
  Rotational spectral line signatures of CO, HCO+, CS, HCN and HNC from a
490-1240 GHz survey with Herschel/HIFI, complemented by ground-based JCMT and
IRAM 30m spectra, cover transitions with E(up)/k between 5 and ~300 K (750K for
12C16O, using selected frequency settings up to 1850 GHz). The resolved
spectral line profiles are used to separate and study various kinematic
components.
  The line profiles show two emission components, the widest and bluest of
which is attributed to an approaching outflow and the other to the envelope. We
find evidence for progressively more redshifted and wider line profiles from
the envelope gas with increasing energy level, qualitatively explained by
residual outflow contribution picked up in the systematically decreasing beam
size. Integrated line intensities for each species decrease as E(up)/k
increases from <50 to 700K. We constrain the following: n(H2)~10^5-10^6 cm^-3
and T~60-200K for the outflow gas; T=9-17K and N(H2)~3x10^21 cm^-2 for a known
foreground absorption cloud; N(H2)<10^19 cm^-2 for a second foreground
component.
  Our spherical envelope radiative transfer model systematically underproduces
observed line emission at E(up)/k > 150 K for all species. This indicates that
warm gas should be added to the model and that the model's geometry should
provide low optical depth pathways for line emission from this warm gas to
escape, for example in the form of UV heated outflow cavity walls viewed at a
favorable inclination angle. Physical and chemical conditions derived for the
outflow gas are similar to those in the protostellar envelope, possibly
indicating that the modest velocity (<10 km/s) outflow component consists of
recently swept-up gas.


title:
Hybrid Electron Spin Resonance and Whispering Gallery Mode Resonance
  Spectroscopy of Fe3+ in Sapphire

abstract:
  The development of a new era of quantum devices requires an understanding of
how paramagnetic dopants or impurity spins behave in crystal hosts. Here, we
describe a new spectroscopic technique which uses traditional Electron Spin
Resonance (ESR) combined with the measurement of a large population of
electromagnetic Whispering Gallery (WG) modes. This allows the characterization
of the physical parameters of paramagnetic impurity ions in the crystal at low
temperatures. We present measurements of two ultra-high purity sapphires cooled
to 20 mK in temperature, and determine the concentration of Fe3+ ions and their
frequency sensitivity to a DC magnetic field. Our method is different to ESR in
that it is possible to track the resonant frequency of the ion from zero
applied magnetic field to any arbitrary value, allowing excellent measurement
precision. This high precision reveals anisotropic behaviour of the Zeeman
splitting, which has not been previously reported. In both crystals, each
Zeeman component demonstrates a different g-factor.


title:
A short proof that all linear codes are weakly algebraic-geometric using
  Bertini theorems of B. Poonen

abstract:
  In this paper we give a simpler proof of a deep theorem proved by Pellikan,
Shen and van Wee that all linear codes are weakly algebraic-geometric using a
theorem of B.Poonen.


title:
Interference of Higgs diphoton signal and background in production with
  a jet at the LHC

abstract:
  The Higgs mass determination from diphoton events at the LHC can be affected
by interference between the Higgs resonant and continuum background amplitudes
with the same initial and final states. For the leading order gluon fusion
process, this shift was previously found to exceed 100 MeV, with some
dependence on the diphoton mass resolution and the methods used to extract and
fit the peak from data. In this paper, I consider the mass shift for the
process pp --> j\gamma\gamma\ that includes an additional central jet in the
final state. For cuts on the transverse momentum of the jet of 25 GeV or more,
the diphoton Higgs peak mass shift due to interference is found to be very
small, due in part to less interference for the gluon-gluon initiated
subprocess, and in part to a cancellation between it and the quark-gluon
initiated subprocess.


title: The Higgs mode in a superfluid of Dirac fermions

abstract:
  We study the Higgs amplitude mode in the s-wave superfluid state on the
honeycomb lattice inspired by recent cold atom experiments. We consider the
attractive Hubbard model and focus on the vicinity of a quantum phase
transition between semi-metal and superfluid phases. On either side of the
transition, we find collective mode excitations that are stable against decay
into quasiparticle-pairs. In the semi-metal phase, the collective modes have
"Cooperon" and exciton character. These modes smoothly evolve across the
quantum phase transition, and become the Anderson-Bogoliubov mode and the Higgs
mode of the superfluid phase. The collective modes are accommodated within a
window in the quasiparticle-pair continuum, which arises as a consequence of
the linear Dirac dispersion on the honeycomb lattice, and allows for sharp
collective excitations. Bragg scattering can be used to measure these
excitations in cold atom experiments, providing a rare example wherein
collective modes can be tracked across a quantum phase transition.


title: Transition from the self-organized to the driven dynamical clusters

abstract:
  We study the mechanism of formation of synchronized clusters in coupled maps
on networks with various connection architectures. The nodes in a cluster are
self- synchronized or driven-synchronized, based on the coupling strength and
underlying network structures. A smaller coupling strength region shows driven
clusters independent of the network rewiring strategies, whereas a larger
coupling strength region shows the transition from the self-organized cluster
to the driven cluster as network connections are rewired to the bi-partite
type. Lyapunov function analysis is performed to understand the dynamical
origin of cluster formation. The results provide insights into the relationship
between the topological clusters which are based on the direct connections
between the nodes, and the dynamical clusters which are based on the functional
behavior of these nodes.


title:
Classification of convergence rates of solutions of perturbed ordinary
  differential equations with regularly varying nonlinearity

abstract:
  In this paper we consider the rate of convergence of solutions of a scalar
ordinary differential equation which is a perturbed version of an autonomous
equation with a globally stable equilibrium. Under weak assumptions on the
nonlinear mean reverting force, we demonstrate that the convergence rate is
preserved when the perturbation decays more rapidly than a critical rate. At
the critical rate, the convergence to equilibrium is slightly slower than the
unperturbed equation, and when the perturbation decays more slowly than the
critical rate, the convergence to equilibrium is strictly slower than that seen
in the unperturbed equation. In the last case, under strengthened assumptions,
a new convergence rate is recorded which depends on the convergence rate of the
perturbation. The latter result relies on the function being regularly varying
at the equilibrium with index greater than unity; therefore, for this class of
regularly varying problems, a classification of the convergence rates is
obtained.


title:
Nuclear superfluidity for antimagnetic rotation in $^{105}$Cd and
  $^{106}$Cd

abstract:
  The effect of nuclear superfluidity on antimagnetic rotation bands in
$^{105}$Cd and $^{106}$Cd are investigated by the cranked shell model with the
pairing correlations and the blocking effects treated by a particle-number
conserving method. The experimental moments of inertia and the reduced $B(E2)$
transition values are excellently reproduced. The nuclear superfluidity is
essential to reproduce the experimental moments of inertia. The two-shears-like
mechanism for the antimagnetic rotation is investigated by examining the shears
angle, i.e., the closing of the two proton hole angular momenta, and its
sensitive dependence on the nuclear superfluidity is revealed.


title: Six signed Petersen graphs, and their automorphisms

abstract:
  Up to switching isomorphism there are six ways to put signs on the edges of
the Petersen graph. We prove this by computing switching invariants, especially
frustration indices and frustration numbers, switching automorphism groups,
chromatic numbers, and numbers of proper 1-colorations, thereby illustrating
some of the ideas and methods of signed graph theory. We also calculate
automorphism groups and clusterability indices, which are not invariant under
switching. In the process we develop new properties of signed graphs,
especially of their switching automorphism groups.


title: Contact Interactions Probe Effective Dark Matter Models at the LHC

abstract:
  Effective field theories provide a simple framework for probing possible dark
matter (DM) models by reparametrising full interactions into a reduced number
of operators with smaller dimensionality in parameter space. In many cases
these models have four particle vertices, e.g. qqXX, leading to the pair
production of dark matter particles, X, at a hadron collider from initial state
quarks, q. In this analysis we show that for many fundamental DM models with
s-channel DM couplings to qq-pairs, these effective vertices must also produce
quark contact interactions (CI) of the form qqqq. The respective effective
couplings are related by the common underlying theory which allows one to
translate the upper limits from one coupling to the other. We show that at the
LHC, the experimental limits on quark contact interactions give stronger
translated limits on the DM coupling than the experimental searches for dark
matter pair production.


title: The three-particle system on a torus

abstract:
  Based on Lippmann-Schwinger equation approach, we discuss a three-particle
system in finite volume. A set of equations which relate the discrete
finite-volume energies to the scattering amplitudes are derived under the
approximation of the isobar model relevant for the case of narrow two- and
three-body resonances.


title:
Variation of Mid and Far-IR Luminosities among Early-Type Galaxies:
  Relation to Stellar Metallicity and Cold Dust

abstract:
  The Hubble morphological sequence from early to late galaxies corresponds to
an increasing rate of specific star formation. The Hubble sequence also follows
a banana-shaped correlation between 24 and 70 micron luminosities, both
normalized with the K-band luminosity. We show that this correlation is
significantly tightened if galaxies with central AGN emission are removed, but
the cosmic scatter of elliptical galaxies in both 24 and 70 micron luminosities
remains significant along the correlation. We find that the 24 micron variation
among ellipticals correlates with stellar metallicity, reflecting emission from
hot dust in winds from asymptotic giant branch stars of varying metallicity.
Infrared surface brightness variations in elliptical galaxies indicate that the
K - 24 color profile is U-shaped for reasons that are unclear. In some
elliptical galaxies cold interstellar dust emitting at 70 and 160 microns may
arise from recent gas-rich mergers. However, we argue that most of the large
range of 70 micron luminosity in elliptical galaxies is due to dust transported
from galactic cores by feedback events in (currently IR-quiet) active galactic
nuclei. Cooler dusty gas naturally accumulates in the cores of elliptical
galaxies due to dust-cooled local stellar mass loss and may accrete onto the
central black hole, releasing energy. AGN-heated gas can transport dust in
cores 5-10 kpc out into the hot gas atmospheres where it radiates extended 70
micron emission but is eventually destroyed by sputtering. This, and some
modest star formation, defines a cycle of dust creation and destruction.
Elliptical galaxies evidently undergo large transient excursions in the banana
plot in times comparable to the sputtering time or AGN duty cycle, 10 Myrs.
Normally regarded as passive, elliptical galaxies are the most active galaxies
in the IR color-color correlation.


title: Static compression of porous dust aggregates

abstract:
  Context: In protoplanetary disks, dust grains coagulate with each other and
grow to form aggregates. As these aggregates grow by coagulation, their filling
factor \phi decreases down to \phi << 1. However, comets, the remnants of these
early planetesimals, have \phi ~ 0.1. Thus, static compression of porous dust
aggregates is important in planetesimal formation. However, the static
compression strength has been investigated only for relatively high density
aggregates (\phi > 0.1). Aims: We investigate and find the compression strength
of highly porous aggregates (\phi << 1). Methods: We perform three dimensional
N-body simulations of aggregate compression with a particle-particle
interaction model. We introduce a new method of static compression: the
periodic boundary condition is adopted and the boundaries move with low speed
to get closer. The dust aggregate is compressed uniformly and isotropically by
themselves over the periodic boundaries. Results: We empirically derive a
formula of the compression strength of highly porous aggregates (\phi << 1). We
check the validity of the compression strength formula for wide ranges of
numerical parameters, such as the size of initial aggregates, the boundary
speed, the normal damping force, and material. We also compare our results to
the previous studies of static compression in the relatively high density
region (\phi > 0.1) and confirm that our results consistently connect to those
in the high density region. The compression strength formula is also derived
analytically.


title: Vacuum-excited surface plasmon polaritons

abstract:
  We separate Maxwell's equations for background media that allow for both
electric and magnetic time-dependence in a generalized Lorenz gauge. In a
process analogous to the dynamical Casimir effect (DCE) we discuss how surface
plasmon polaritons (SPP)s can be created out of vacuum, via the time-dependent
variation of a dielectric and magnetic insulator at a metal interface for TM
and TE branches, respectively. We suggest how to extend currently proposed DCE
experiments to set up and detect these excitations. Numerical simulations
(without any approximation) indicate that vacuum excited SPPs can be of a
similar magnitude to the photon creation rate in such experiments. Potential
benefits of detecting vacuum excited SPPs, as opposed to DCE photons, are that
parametric enhancement does not require a sealed cavity in the axial direction
and the detection apparatus might be able to use simple phase matching
techniques. For the case of constant permeability, $\mu$, TM branch SPPs and
photons do not suffer from detuning and attenuation like TE photons.

categories: quant-ph cond-mat.mes-hall hep-th physics.optics


title:
Drag and Diffusion coefficients in extreme scenarios of temperature and
  chemical potential

abstract:
  A comparative study of high and zero temperature plasma for the case of
damping rate, drag and diffusion coefficients have been presented. In each of
these quantities, it is revealed how the magnetic interaction dominates over
the electric one at zero temperature unlike what happens at high temperature.


title: Delay-induced driven patterns in coupled Cayley tree networks

abstract:
  We study effects of delay in diffusively coupled logistic maps on the Cayley
tree networks. We find that smaller coupling values exhibits sensitiveness for
value of delay, and leads to different cluster patterns of self-organized and
driven types. Whereas larger coupling strengths are very robust against change
in delay values, and leads to stable driven clusters comprising only nodes from
last generation of the Calaye tree. Furthermore, introduction of delay exhibits
suppression as well as enhancement of synchronization depending upon coupling
strength values, hence demonstrating richness of the model. To the end we
relate the results with social conflicts and cooperation observed in families.


title:
Prediction of (TiO2)x(Cu2O)y Alloys for Photoelectrochemical Water
  Splitting

abstract:
  The formation of (TiO2)x(Cu2O)y solid-solutions are investigated using a
global optimization evolutionary algorithm. First-principles calculations based
on density functional theory are then used to gain insight into the electronic
properties of these alloys. We find that: (i) Ti and Cu in (TiO2)x(Cu2O)y
alloys have similar local environments as in bulk TiO2 and Cu2O except for
(TiO2)(Cu2O) which has some trigonal-planar Cu ions. (ii) The predicted optical
band gaps are around 2.1 eV (590 nm), thus having much better performance for
the absorption of visible light compared with both binary oxides. (iii)
(TiO2)2(Cu2O) has the lowest formation energy amongst all studied alloys and
the positions of its band edges are found to be suitable for solar-driven water
splitting applications.


title: Dark radiation and dark matter coupled to holographic Ricci dark energy

abstract:
  We investigate a universe filled with interacting dark matter, holographic
dark energy, and dark radiation for the spatially flat
Friedmann-Robertson-Walker (FRW) spacetime. We use a linear interaction to
reconstruct all the component energy densities in terms of the scale factor by
directly solving the balance's equations along with the source equation. We
apply the $\chi^{2}$ method to the observational Hubble data for constraining
the cosmic parameters, contrast with the Union 2 sample of supernovae, and
analyze the amount of dark energy in the radiation era. It turns out that our
model exhibits an excess of dark energy in the recombination era whereas the
stringent bound $\Omega_{\rm x}(z\simeq 10^{10})<0.21$ at big-bang
nucleosynthesis is fulfilled. We find that the interaction provides a physical
mechanism for alleviating the triple cosmic coincidence and this leads to
$\Omega_{\rm m0}/\Omega_{\rm x0} \simeq \Omega_{\rm r0}/\Omega_{\rm x0} \simeq
{\cal O}(1)$.


title:
Perturbative Bottom-up Approach for Neutrino Mass Matrix in Light of
  Large \theta_{13} and Role of Lightest Neutrino Mass

abstract:
  We discuss the role of lightest neutrino mass (m_0) in the neutrino mass
matrix, defined in a flavor basis, through a bottom-up approach using the
current neutrino oscillation data. We find that if m_0 < 10^{-3} eV, then the
deviation \delta M_\nu in the neutrino mass matrix from a tree-level, say
tribimaximal neutrino mass matrix, does not depend on m_0. As a result \delta
M_\nu's are exactly predicted in terms of the experimentally determined
quantities such as solar and atmospheric mass squared differences and the
mixing angles. On the other hand for m_0 \gsim 10^{-3} eV, \delta M_\nu
strongly depends on m_0 and hence can not be determined within the knowledge of
oscillation parameters alone. In this limit, we provide an exponential
parameterization for \delta M_\nu for all values of m_0 such that it can
factorize the m_0 dependency of \delta M_\nu from rest of the oscillation
parameters. This helps us in finding \delta M_\nu as a function of the solar
and atmospheric mass squared differences and the mixing angles for all values
of m_0. We use this information to build up a model of neutrino masses and
mixings in a top-down scenario which can predict large \theta_{13}
perturbatively.


title: Object-Image Correspondence for Algebraic Curves under Projections

abstract:
  We present a novel algorithm for deciding whether a given planar curve is an
image of a given spatial curve, obtained by a central or a parallel projection
with unknown parameters. The motivation comes from the problem of establishing
a correspondence between an object and an image, taken by a camera with unknown
position and parameters. A straightforward approach to this problem consists of
setting up a system of conditions on the projection parameters and then
checking whether or not this system has a solution. The computational advantage
of the algorithm presented here, in comparison to algorithms based on the
straightforward approach, lies in a significant reduction of a number of real
parameters that need to be eliminated in order to establish existence or
non-existence of a projection that maps a given spatial curve to a given planar
curve. Our algorithm is based on projection criteria that reduce the projection
problem to a certain modification of the equivalence problem of planar curves
under affine and projective transformations. To solve the latter problem we
make an algebraic adaptation of signature construction that has been used to
solve the equivalence problems for smooth curves. We introduce a notion of a
classifying set of rational differential invariants and produce explicit
formulas for such invariants for the actions of the projective and the affine
groups on the plane.


title:
Facile implementation of integrated tempering sampling method to enhance
  the sampling over a broad range of temperatures

abstract:
  Integrated tempering sampling (ITS) method is an approach to enhance the
sampling over a broad range of energies and temperatures in computer
simulations. In this paper, a new version of integrated tempering sampling
method is proposed. In the new approach presented here, we obtain parameters
such as the set of temperatures and the corresponding weighting factors from
canonical average of potential energies. These parameters can be easily
obtained without estimating partition functions. We apply this new approach to
study the Lennard-Jones fluid, the ALA-PRO peptide and the single polymer chain
systems to validate and benchmark the method.


title:
Theoretical considerations of laser induced liquid-liquid interface
  deformation

abstract:
  In the increasingly active field of optofluidics, a series of experiments
involving near-critical two-fluid interfaces have shown a number of interesting
non-linear effects. We here offer, for the first time to our knowledge, an
explanation for one such feature, observed in experiments by Casner and
Delville [Phys. Rev. Lett. {\bf 90}, 144503 (2003)], namely the sudden
formation of "shoulder"-like shapes in a laser-induced deformation of the
liquid-liquid interface at high laser power. Two candidate explanations are the
following: firstly, that the shape can be explained by balancing forces of
buoyancy, laser pull and surface tension only, and that the observed change of
deformation shape is the sudden jump from one solution of the strongly
nonlinear governing differential equation to another. Secondly, it might be
that the nontrivial shape observed could be the result of temperature gradients
due to local absorptive heating of the liquid. We report that a systematic
search for solutions of the governing equation in the first case yields no
trace of solutions containing such features. By contrast, an investigation of
the second option shows that the narrow shape of the tip of the deformation can
be explained by a slight {\it heating} of the liquids. The local heating
amounts to a few kelvins, with the parameters given, although there are
uncertainties here. Our investigations suggest that local temperature
variations are the crucial element behind the instability and the shoulder-like
deformation.


title:
Structure, equation of state, diffusion and viscosity of warm dense Fe
  under the conditions of giant planet core

abstract:
  Fe exists abundantly in the universe. In particular, the dynamical structures
and transport properties of warm dense Fe are crucial for understanding the
evolution and structures of giant planets. In this article, we present the
ionic structures, equation of states, diffusion and viscosity of Fe at two
typical densities of 33.385 g/cm$^3$ and 45 g/cm$^3$ in the temperature range
of 1 eV and 10 eV, giving the data by the first principles calculations using
quantum Langevin molecular dynamics (QLMD). Furthermore, the validation of
Stokes-Einstein (SE) relation in this regime is discussed, showing the
importance of choosing the effective atomic diameter. The results remind us of
the careful usage of the SE relation under extreme conditions.

categories: astro-ph.EP cond-mat.mtrl-sci physics.chem-ph physics.comp-ph


title:
Characteristics of Compound Multiplicity in 84^Kr_36 with various light
  and heavy targets at 1 GeV per nucleon

abstract:
  Present article focuses on the interactions of 84 Kr 36 having kinetic energy
around 1 GeV per nucleon with NIKFI BR2 nuclear emulsion detectors targets,
that can reveal important features of some compound multiplicity. The
observation showed that the width of the compound multiplicity distributions
and value of the mean compound multiplicity have linear relation with the mass
number of the projectile as well as colliding system.


title: Arc Statistics

abstract:
  The existence of an arc statistics problem was at the center of a strong
debate in the last fifteen years. With the aim to clarify if the optical depth
for giant gravitational arcs by galaxy clusters in the so called concordance
model is compatible with observations, several studies were carried out which
helped to significantly improve our knowledge of strong lensing clusters,
unveiling their extremely complex internal structure. In particular, the
abundance and the frequency of strong lensing events like gravitational arcs
turned out to be a potentially very powerful tool to trace the structure
formation. However, given the limited size of observational and theoretical
data-sets, the power of arc statistics as a cosmological tool has been only
minimally exploited so far. On the other hand, the last years were
characterized by significant advancements in the field, and several cluster
surveys that are ongoing or planned for the near future seem to have the
potential to make arc statistics a competitive cosmological probe.
Additionally, recent observations of anomalously large Einstein radii and
concentrations in galaxy clusters have reinvigorated the debate on the arc
statistics problem. In this paper, we review the work done so far on arc
statistics, focussing on what is the lesson we learned and what is likely to
improve in the next years.


title: Kinetics of polarization in non-relativistic scattering

abstract:
  An approach is developed, which essentially simplifies derivation of kinetic
equation for polarization in non-relativistic scattering. This approach is
applicable for collision of projectile particles with a target for any spins of
colliding particles. The most detailed consideration is performed for the case
of spin 1/2 projectile particle interacting with spin 1/2 particle of a target.
The solution of the kinetic equation for the case of zero initial polarization
is presented.


title: Adaptive Priors based on Splines with Random Knots

abstract:
  Splines are useful building blocks when constructing priors on nonparametric
models indexed by functions. Recently it has been established in the literature
that hierarchical priors based on splines with a random number of equally
spaced knots and random coefficients in the B-spline basis corresponding to
those knots lead, under certain conditions, to adaptive posterior contraction
rates, over certain smoothness functional classes. In this paper we extend
these results for when the location of the knots is also endowed with a prior.
This has already been a common practice in MCMC applications, where the
resulting posterior is expected to be more "spatially adaptive", but a
theoretical basis in terms of adaptive contraction rates was missing. Under
some mild assumptions, we establish a result that provides sufficient
conditions for adaptive contraction rates in a range of models.


title:
Derivation of Lindblad master equation for the quantum Ising model
  interacting with a heat bath

abstract:
  Starting from the Liouville-von Neumann equation, under a weak coupling limit
we derive the Lindblad master equation for the one-dimensional quantum Ising
model in a Markov approximation and a rotating wave approximation. We also
prove that the steady solution of the Lindblad equation is the canonical
distribution independent of the dissipation rate.


title:
Ground state of a resonant two-qubit Rabi model in the ultrastrong
  coupling regime

abstract:
  We consider a generalized Rabi model formed by two identical qubits
interacting with a common oscillator mode. In the near resonance configuration
where the oscillator frequency is close to the transition frequency of the
qubit, we determine the ground state of the model approximately by using a
variational method and a transformation method. Both methods are shown to
provide good agreement with the exact numerical ground state for a range of
coupling strength in the ultrastrong regime. In addition, we indicate how the
accuracy of the approximation can be further improved by using perturbation
theory. We also examine the ground state entanglement between the two qubits.
By calculating the negativity, we quantify the degree of entanglement as a
function of coupling strength.


title:
Third generation stellar models for asteroseismology of hot B subdwarf
  stars. A test of accuracy with the pulsating eclipsing binary PG 1336--018

abstract:
  Context. Asteroseismic determinations of structural parameters of hot B
subdwarfs (sdB) have been carried out for more than a decade now. These
analyses rely on stellar models whose reliability for the required task needs
to be evaluated critically. Aims. We present new models of the so-called third
generation (3G) dedicated to the asteroseismology of sdB stars. These
parameterized models are complete static structures suitable for analyzing both
p- and g-mode pulsators, contrary to the former second generation (2G) models
that were limited to p-modes. While the reliability of the 2G models has been
successfully verified in the past, this important test still has to be
conducted on the 3G structures. Methods. The close eclipsing binary PG 1336-018
provides a unique opportunity to test the reliability of sdB models. We
compared the structural parameters of the sdB component in PG 1336-018 obtained
from asteroseismology based on the 3G models, with those derived independently
from the modeling of the reflection/irradiation effect and the eclipses
observed in the light curve. Results. The stellar parameters inferred from
asteroseismology using the 3G models are found to be remarkably consistent with
both the preferred orbital solution obtained from the binary light curve
modeling and the updated spectroscopic estimates for the surface gravity of the
star. We also show that the uncertainties on the input physics included in
stellar models have no noticeable impact, at the current level of accuracy, on
the structural parameters derived by asteroseismology. Conclusions. The stellar
models presently used to carry out quantitative seismic analyses of sdB stars
are reliable for the task. The stellar parameters inferred by this technique,
at least for those that could be tested (M*, R*, and log g), appear to be both
very precise and accurate, as no significant systematic effect has been found.


title:
Ooguri-Vafa Invariants and Off-shell Superpotentials of Type II/F-theory
  compactification

abstract:
  In this paper, we make a further step of \cite{Feng} and calculate off-shell
superpotential of two Calabi-Yau manifold with three parameters by integrating
the period of subsystem. We also obtain the Ooguri-Vafa invariants with open
mirror symmetry.


title:
DNA hybridization kinetics: zippering, internal displacement and
  sequence dependence

abstract:
  While the thermodynamics of DNA hybridization is well understood, much less
is known about the kinetics of this classic system. Filling this gap in our
understanding has new urgency because DNA nanotechnology often depends
critically on binding rates. Here we use a coarse-grained model to explore the
hybridization kinetics of DNA oligomers, finding that strand association
proceeds through a complex set of intermediate states. Successful binding
events start with the formation of a few metastable base-pairing interactions,
followed by zippering of the remaining bonds. However, despite reasonably
strong interstrand interactions, initial contacts frequently fail to lead to
zippering because the typical configurations in which they form differ from
typical states of similar enthalpy in the double-stranded equilibrium ensemble.
Therefore, if the association process is analyzed on the base-pair (secondary
structure) level, it shows non-Markovian behavior. Initial contacts must be
stabilized by two or three base pairs before full zippering is likely,
resulting in negative effective activation enthalpies. Non-Arrhenius behavior
is observed as the number of base pairs in the effective transition state
increases with temperature. In addition, we find that alternative pathways
involving misbonds can increase association rates. For repetitive sequences,
misaligned duplexes frequently rearrange to form fully paired duplexes by two
distinct processes which we label `pseudoknot' and `inchworm' internal
displacement. We show how the above processes can explain why experimentally
observed association rates of GC-rich oligomers are higher than rates of
AT-rich equivalents. More generally, we argue that association rates can be
modulated by sequence choice.


title: Nets, relations and linking diagrams

abstract:
  In recent work, the author and others have studied compositional algebras of
Petri nets. Here we consider mathematical aspects of the pure linking algebras
that underly them. We characterise composition of nets without places as the
composition of spans over appropriate categories of relations, and study the
underlying algebraic structures.


title:
The height evolution of the `true' CME mass derived from STEREO COR1 and
  COR2 observations

abstract:
  Using combined STEREO-A and STEREO-B EUVI, COR1 and COR2 data, we derive
deprojected CME kinematics and CME `true' mass evolutions for a sample of 25
events that occurred during December 2007 to April 2011. We develop a fitting
function to describe the CME mass evolution with height. The function considers
both the effect of the coronagraph occulter, at the beginning of the CME
evolution, and an actual mass increase. The latter becomes important at about
10Rs to 15Rs and is assumed to mostly contribute up to 20Rs. The mass increase
ranges from 2% to 6% per Rs and, is positively correlated to the total CME
mass. Due to the combination of COR1 and COR2 mass measurements, we are able to
estimate the `true' mass value for very low coronal heights (< 3Rs). Based on
the deprojected CME kinematics and initial ejected masses, we derive the
kinetic energies and propelling forces acting on the CME in the low corona (<
3Rs). The derived CME kinetic energies range between 1-66*10^23 J, and the
forces range between 2.2-510*10^14 N.


title: redMaPPer II: X-ray and SZ Performance Benchmarks for the SDSS Catalog

abstract:
  We evaluate the performance of the SDSS DR8 redMaPPer photometric cluster
catalog by comparing it to overlapping X-ray and SZ selected catalogs from the
literature. We confirm the redMaPPer photometric redshifts are nearly unbiased
(<\Delta z> < 0.005), have low scatter (\sigma_z ~ 0.006-0.02, depending on
redshift), and have a low catastrophic failure rate (~ 1%). Both the
T_X-\lambda\ and Mgas-\lambda\ scaling relations are consistent with a mass
scatter of \sigma_{\ln M|\lambda} ~ 25%, albeit with a ~ 1% outlier rate due to
projection effects. This failure rate is somewhat lower than that expected for
the full cluster sample, but is consistent with the additional selection
effects introduced by our reliance on X-ray and SZ selected reference cluster
samples. Where the redMaPPer DR8 catalog is volume limited (z < 0.35), the
catalog is 100% complete above T_X > 3.5 keV, and L_X > 2\times 10^{44} erg/s,
decreasing to 90% completeness at L_X ~ 10^{43} erg/s. All rich (\lambda >
100), low redshift (z < 0.25) redMaPPer clusters are X-ray detected in the
ROSAT All Sky Survey (RASS), and 86% of the clusters are correctly centered.
Compared to other SDSS photometric cluster catalogs, redMaPPer has the highest
completeness and purity, and the best photometric redshift performance, though
some algorithms do achieve comparable performance to redMaPPer in subsets of
the above categories and/or in limited redshift ranges. The redMaPPer richness
is clearly the one that best correlates with X-ray temperature and gas mass.
Most algorithms (including redMaPPer) have very similar centering performance,
with only one exception which performs worse.


title: Production of carbon-rich presolar grains from massive stars

abstract:
  About a year after core collapse supernova, dust starts to condense in the
ejecta. In meteorites, a fraction of C-rich presolar grains (e.g., silicon
carbide (SiC) grains of Type-X and low density graphites) are identified as
relics of these events, according to the anomalous isotopic abundances. Several
features of these abundances remain unexplained and challenge the understanding
of core-collapse supernovae explosions and nucleosynthesis. We show, for the
first time, that most of the measured C-rich grain abundances can be accounted
for in the C-rich material from explosive He burning in core-collapse
supernovae with high shock velocities and consequent high temperatures. The
inefficiency of the $^{12}$C($\alpha$,$\gamma$)$^{16}$O reaction relative to
the rest of the $\alpha$-capture chain at $T > 3.5\times10^8 \mathrm{K}$ causes
the deepest He-shell material to be carbon rich and silicon rich, and depleted
in oxygen. The isotopic ratio predictions in part of this material, defined
here as the C/Si zone, are in agreement with the grain data. The
high-temperature explosive conditions that our models reach at the bottom of
the He shell, can also be representative of the nucleosynthesis in hypernovae
or in the high-temperature tail of a distribution of conditions in asymmetric
supernovae. Finally, our predictions are consistent with the observation of
large $^{44}$Ca/$^{40}$Ca observed in the grains. This is due to the production
of $^{44}$Ti together with $^{40}$Ca in the C/Si zone, and/or to the strong
depletion of $^{40}$Ca by neutron captures.


title: Absorbing gas around the WASP-12 planetary system

abstract:
  Near-UV observations of the planet host star WASP-12 uncovered the apparent
absence of the normally conspicuous core emission of the Mg2 h&k resonance
lines. This anomaly could be due either to (1) a lack of stellar activity,
which would be unprecedented for a solar-like star of the imputed age of
WASP-12; or (2) extrinsic absorption, from the intervening interstellar medium
(ISM) or from material within the WASP-12 system itself, presumably ablated
from the extreme hot Jupiter WASP-12b. HIRES archival spectra of the Ca2 H&K
lines of WASP-12 show broad depressions in the line cores, deeper than those of
other inactive and similarly distant stars and similar to WASP-12's Mg2 h&k
line profiles. We took high resolution ESPADONS and FIES spectra of three
early-type stars within 20' of WASP-12 and at similar distances, which show the
ISM column is insufficient to produce the broad Ca2 depression observed in
WASP-12. The EBHIS H1 column density map supports and strengthens this
conclusion. Extrinsic absorption by material local to the WASP-12 system is
therefore the most likely cause of the line core anomalies. Gas escaping from
the heavily irradiated planet could form a stable and thick circumstellar
disk/cloud. The anomalously low stellar activity index (logR'HK) of WASP-12 is
evidently a direct consequence of the extra core absorption, so similar HK
index deficiencies might signal the presence of translucent circumstellar gas
around other stars hosting evaporating planets.


title: Automorphisms of real Lie algebras of dimension five or less

abstract:
  The Lie algebra version of the Krull-Schmidt Theorem is formulated and
proved. This leads to a method for constructing the automorphisms of a direct
sum of Lie algebras from the automorphisms of its indecomposable components.
For finite-dimensional Lie algebras, there is a well-known algorithm for
finding such components, so the theorem considerably simplifies the problem of
classifying the automorphism groups. We illustrate this by classifying the
automorphisms of all indecomposable real Lie algebras of dimension five or
less. Our results are presented very concisely, in tabular form.


title: Canonical surfaces with big cotangent bundle

abstract:
  Surfaces of general type with positive second Segre number are known to have
big cotangent bundle. We give a new criterion ensuring that a surface of
general type with canonical singularities has a minimal resolution with big
cotangent bundle. This provides many examples of surfaces with negative second
Segre number and big cotangent bundle.


title: Total Variation of the Control and Energy of Bilinear Quantum Systems

abstract:
  In the present note, we give two examples of bilinear quantum systems showing
good agreement between the total variation of the control and the variation of
the energy of solutions, with bounded or unbounded coupling term. The
corresponding estimates in terms of the total variation of the control appear
to be optimal.


title:
Quantum-mechanical nonequivalence of metrics of centrally symmetric
  uncharged gravitational field

abstract:
  Quantum-mechanical analysis shows that the metrics of a centrally symmetric
uncharged gravitational field, which are exact solutions of the general
relativity equations, are physically non-equivalent. The classical
Schwarzschield metric and the Schwarzschild metrics in isotropic and harmonic
coordinates provide for the existence of stationary bound states of Dirac
particles with a real energy spectrum. The Hilbert condition g_{00}>0 is
responsible for zero values of the wave functions under the "event horizon"
that leads to the absence of Hawking radiation. For the Eddington-Finkelstein
and Painleve-Gullstrand metrics, stationary bound states of spin-half particles
cannot exist because Dirac Hamiltonians are non-Hermitian. For these metrics,
the condition g_{00}>0 also leads to the absence of Hawking evaporation. For
the Finkelstein-Lemaitre and Kruskal metrics, Dirac Hamiltonians are explicitly
time-dependent, and stationary bound states of spin-half particles cannot exist
for them. The Hilbert condition for these metrics does not place any
constraints on the domains of the wave functions. Hawking evaporation of black
holes is possible in this case. The results can lead to revisiting some
concepts of the standard cosmological model related to the evolution of the
universe and interaction of collapsars with surrounding matter.


title: Impacts of satellite galaxies on the redshift-space distortions

abstract:
  We study the impacts of the satellite galaxies on the redshift-space
distortions. In our multipole power spectrum analysis of the luminous red
galaxies (LRGs) samples of the Sloan Digital Sky Survey (SDSS), we have clearly
detected the non-zero signature of the hexadecapole and tetrahexadecapole
spectrum, which almost disappears in the power spectrum with the sample of the
brightest LRGs only. We thus demonstrate that the satellite LRGs in multiple
systems make a significant contribution to the multipole power spectrum though
its fraction is small. The behavior can be understood by a simple halo model,
in which the one-halo term, describing the Finger of God (FoG) effect from the
satellite galaxies, makes the dominant contribution to the higher multipole
spectra. We demonstrate that the small-scale information of higher multipole
spectrum is useful for calibrating the satellite FoG effect and improves the
measurement of the cosmic growth rate dramatically. We further demonstrate that
the fiber collision in the galaxy survey influences the one-halo term and the
higher multipole spectra, because the number of satellite galaxies in the halo
occupation distribution (HOD) is changed. We also discuss about the impact of
satellite galaxies on future high-redshift surveys targeting the H-alpha
emitters.


title:
Discrete versions of the transport equation and the Shepp-Olkin
  conjecture

abstract:
  We introduce a framework to consider transport problems for integer-valued
random variables. We introduce weighting coefficients which allow us to
characterize transport problems in a gradient flow setting, and form the basis
of our introduction of a discrete version of the Benamou-Brenier formula.
Further, we use these coefficients to state a new form of weighted
log-concavity. These results are applied to prove the monotone case of the
Shepp-Olkin entropy concavity conjecture.


title:
Disorder, critical currents, and vortex pinning energies in isovalently
  substituted BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$

abstract:
  We present a comprehensive overview of vortex pinning in single crystals of
the isovalently substituted iron-based superconductor
BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$, a material that qualifies as an
archetypical clean superconductor, containing only sparse strong point-like
pins [in the sense of C.J. van der Beek {\em et al.}, Phys. Rev. B {\bf 66},
024523 (2002)]. Widely varying critical current values for nominally similar
compositions show that flux pinning is of extrinsic origin. Vortex
configurations, imaged using the Bitter decoration method, show less density
fluctuations than those previously observed in charge-doped
Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ single crystals. Analysis reveals that the
pinning force and -energy distributions depend on the P-content $x$. However,
they are always much narrower than in Ba(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$, a
result that is attributed to the weaker temperature dependence of the
superfluid density on approaching $T_{c}$ in
BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$. Critical current density measurements and
pinning force distributions independently yield a mean distance between
effective pinning centers $\bar{\mathcal L} \sim 90$ nm, increasing with
increasing P-content $x$. This evolution can be understood as being the
consequence of the P-dependence of the London penetration depth. Further
salient features are a wide vortex free "Meissner belt", observed at the edge
of overdoped crystals, and characteristic chain-like vortex arrangements,
observed at all levels of P-substitution.


title:
Significance of the Casimir force and surface roughness for actuation
  dynamics of MEMS

abstract:
  Using the measured optical response and surface roughness topography as
inputs, we perform realistic calculations of the combined effect of Casimir and
electrostatic forces on the actuation dynamics of micro-electromechanical
systems (MEMS). In contrast with the expectations, roughness can influence MEMS
dynamics even at distances between bodies significantly larger than the
root-mean-square roughness. This effect is associated with statistically rare
high asperities that can be locally close to the point of contact. It is found
that, even though surface roughness appears to have a detrimental effect on the
availability of stable equilibria, it ensures that those equilibria can be
reached more easily than in the case of flat surfaces. Hence our findings play
a principal role for the stability of microdevices such as vibration sensors,
switches, and other related MEM architectures operating at distances below 100
nm.


title:
From GWAS to transcriptomics in prospective cancer design - new
  statistical challenges

abstract:
  Background. With the increasing interest in post-GWAS research which
represents a transition from genome-wide association discovery to analysis of
functional mechanisms, attention has been lately focused on the potential of
including various biological material in epidemiological studies. In
particular, exploration of the carcinogenic process through transcriptional
analysis at the epidemiological level opens up new horizons in functional
analysis and causal inference, and requires a new design together with adequate
analysis procedures.
  Results. In this article, we present the post-genome design implemented in
the NOWAC cohort as an example of a prospective nested case-control study built
for transcriptomics use, and discuss analytical strategies to explore the
changes occurring in transcriptomics during the carcinogenic process in
association with questionnaire information. We emphasize the inadequacy of
survival analysis models usually considered in GWAS for post-genome design, and
propose instead to parameterize the gene trajectories during the carcinogenic
process.
  Conclusions. This novel approach, in which transcriptomics are considered as
potential intermediate biomarkers of cancer and exposures, offers a flexible
framework which can include various biological assumptions.


title: Incidence Matrices of Finite Quadratic Spaces

abstract:
  In this paper, we first prove the 2-rank of full incidence matrix of PG(n,q)
with $q$ an odd prime power. Then by the quadratic form defined on PG(n,q), the
points of it are classified as isotropic and anisotropic points. We divide the
full incidence matrix into four sub-matrices. Then by using the software
package Magma, we give a general conjecture for the 2-rank of sub-matrices of
the full incidence matrix in PG(n,q) and prove it in the case of n=1, 2.


title: An Optimal Randomized Online Algorithm for Reordering Buffer Management

abstract:
  We give an $O(\log\log k)$-competitive randomized online algorithm for
reordering buffer management, where $k$ is the buffer size. Our bound matches
the lower bound of Adamaszek et al. (STOC 2011). Our algorithm has two stages
which are executed online in parallel. The first stage computes
deterministically a feasible fractional solution to an LP relaxation for
reordering buffer management. The second stage "rounds" using randomness the
fractional solution. The first stage is based on the online primal-dual schema,
combined with a dual fitting argument. As multiplicative weights steps and dual
fitting steps are interleaved and in some sense conflicting, combining them is
challenging. We also note that we apply the primal-dual schema to a relaxation
with mixed packing and covering constraints. We pay the $O(\log\log k)$
competitive factor for the gap between the computed LP solution and the optimal
LP solution. The second stage gives an online algorithm that converts the LP
solution to an integral solution, while increasing the cost by an O(1) factor.
This stage generalizes recent results that gave a similar approximation factor
for rounding the LP solution, albeit using an offline rounding algorithm.


title: On the partitions with Sturmian-like refinements

abstract:
  In the dynamics of a rotation of the unit circle by an irrational angle
$\alpha\in(0,1)$, we study the evolution of partitions whose atoms are finite
unions of left-closed right-open intervals with endpoints lying on the past
trajectory of the point $0$. Unlike the standard framework, we focus on
partitions whose atoms are disconnected sets. We show that the refinements of
these partitions eventually coincide with the refinements of a preimage of the
Sturmian partition, which consists of two intervals $[0,1-\alpha)$ and
$[1-\alpha,1)$. In particular, the refinements of the partitions eventually
consist of connected sets, i.e., intervals. We reformulate this result in terms
of Sturmian subshifts: we show that for every non-trivial factor mapping from a
one-sided Sturmian subshift, satisfying a mild technical assumption, the
sliding block code of sufficiently large length induced by the mapping is
injective.


title: Degree and clustering coefficient in sparse random intersection graphs

abstract:
  We establish asymptotic vertex degree distribution and examine its relation
to the clustering coefficient in two popular random intersection graph models
of Godehardt and Jaworski [Electron. Notes Discrete Math. 10 (2001) 129-132].
For sparse graphs with a positive clustering coefficient, we examine
statistical dependence between the (local) clustering coefficient and the
degree. Our results are mathematically rigorous. They are consistent with the
empirical observation of Foudalis et al. [In Algorithms and Models for Web
Graph (2011) Springer] that, "clustering correlates negatively with degree."
Moreover, they explain empirical results on $k^{-1}$ scaling of the local
clustering coefficient of a vertex of degree k reported in Ravasz and Barabasi
[Phys. Rev. E 67 (2003) 026112].


title: Exchange effects in plasmas: the case of low-frequency dynamics

abstract:
  Recently, there has been a surge in the interest of non-equilibrium
collective quantum models, where particle dispersion and spin are examples of
effects taken into account. Here, we derive a kinetic plasma model con- taining
fermion exchange effects. Exchange interactions are of great importance in many
systems, and have no classical analogy. Our model therefore constitute a
possible probe of collective quantum phenomena in new regimes. As an example,
we consider the influence of exchange effect on low frequency dynamics, in
partic- ular ion acoustic waves. Comparisons to related computational
techniques are given and the differences are highlighted. Furthermore, we
discuss the applicability of our model, its limitations and possible
extensions.


title:
Conjugate distributions in hierarchical Bayesian ANOVA for computational
  efficiency and assessments of both practical and statistical significance

abstract:
  Assessing variability according to distinct factors in data is a fundamental
technique of statistics. The method commonly regarded to as analysis of
variance (ANOVA) is, however, typically confined to the case where all levels
of a factor are present in the data (i.e. the population of factor levels has
been exhausted). Random and mixed effects models are used for more elaborate
cases, but require distinct nomenclature, concepts and theory, as well as
distinct inferential procedures. Following a hierarchical Bayesian approach, a
comprehensive ANOVA framework is shown, which unifies the above statistical
models, emphasizes practical rather than statistical significance, addresses
issues of parameter identifiability for random effects, and provides
straightforward computational procedures for inferential steps. Although this
is done in a rigorous manner the contents herein can be seen as ideological in
supporting a shift in the approach taken towards analysis of variance.


title: US Corporate Bond Yield Spread : A default risk debate

abstract:
  According to theoretical models of valuing risky corporate securities, risk
of default is primary component in overall yield spread. However, sizable
empirical literature considers it otherwise by giving more importance to
non-default risk factors. Current study empirically attempts to provide
relative solution to this conundrum by presuming that problem lies in the
subjective empirical treatment of default risk. By using post-hoc estimator
approach of Lubotsky & Wittenberg (2006), we construct an efficient indicator
for risk of default, by using sample of 252 US non-financial corporate data
(2000-2010). On average, our results validate that almost 48% of change in
yield spread is explained by default risk especially in recent financial crisis
period (2007-2009). Hence, our results relatively suggest that potential
problem lies in the ad-hoc measurement methods used in existing empirical
literature.