title: Constraining Modified Chaplygin gas parameters

abstract:
  We investigate the evolution of a FRW model fuelled by a modified Chaplygin
gas with an equation of state $p = A\rho -\frac{B}{\rho^\alpha}$. An attempt is
made here to constrain the free parameters of MCG model through the wellknown
contour plot technique using observational data. The permissible range of
values of the pair of free parameters are determined to study the viability of
cosmological models \emph{vis-a-vis} observational results. Aside from allowing
the desirable feature of \emph{flip} of the sign of deceleration parameter we
also find that the transition from the decelerating to the accelerating phase
occurs at relatively low value of redshift in accordance with the observational
prediction that the acceleration is a recent phenomenon. It is found that the
effective acoustic speed may become imaginary depending upon the initial
conditions signalling that perturbations associated with instability sets in
resulting in structure formation. As one considers more negative values of $A$
the \emph{flip} in sign is delayed resulting the density parameter to change
fast. Again it is found from the contour plot that compatibility with
observational results is admitted with a value of $A$ which is very near to
zero or a small negative number.


title:
Strang Splitting Methods for a quasilinear Schr\"odinger equation -
  Convergence, Instability and Dynamics

abstract:
  We study the Strang splitting scheme for quasilinear Schr\"odinger equations.
We establish the convergence of the scheme for solutions with small initial
data. We analyze the linear instability of the numerical scheme, which explains
the numerical blow-up of large data solutions and connects to analytical
breakdown of regularity of solutions to quasilinear Schr\"odinger equations.
Numerical tests are performed for a modified version of the superfluid thin
film equation.


title:
Observation of isosceles triangular electronic structure around excess
  iron atoms in Fe$_{1+\delta}$Te

abstract:
  We present scanning tunneling microscopy and spectroscopy studies around an
individual excess Fe atom, working as a local perturbation, in the parent
material of the iron-chalcogenide superconductor Fe$_{1+\delta}$Te.
Spectroscopic imaging reveals a novel isosceles triangular electronic structure
around the excess Fe atoms. Its spatial symmetry reects the underlying
bicollinear antiferromagnetic spin state and the structural monoclinic
symmetry. These findings provide important clues to understand the role of the
excess Fe atoms, which complicate the understanding of the phenomena occurring
in iron-chalcogenide materials.


title:
On the Average Value of the Canonical Height in Higher Dimensional
  Families of Elliptic curves

abstract:
  Given an elliptic curve E over a function field K=Q(T_1,...,T_n), we study
the behavior of the canonical height ^h_(E_w) of the specialized elliptic curve
E_w with respect to the height of w in Q^n. In this paper, we prove that there
exists a uniform non-zero lower bound for the average of the quotient
^h_(E_w)(P_w)/h(w) for all non-torsion P in E(K).


title: Eigenvalue estimates for the resolvent of a non-normal matrix

abstract:
  We investigate the relation between the spectrum of a non-normal matrix and
the norm of its resolvent. We provide spectral estimates for the resolvent of
matrices whose largest singular value is bounded by $1$ (so-called Hilbert
space contractions) and for power-bounded matrices. In the first case our
estimate is optimal and we present explicit matrices that achieve equality in
the bound. This result recovers and generalizes previous estimates obtained by
E.B. Davies and B. Simon in the study of orthogonal polynomials on the unit
circle. In case of power-bounded matrices we achieve the strongest estimate so
far. Our result unifies previous approaches, where the resolvent was estimated
in certain restricted regions of the complex plane. To achieve our estimates we
relate the problem of bounding the norm of a function of a matrix to a
Nevanlinna-Pick interpolation problem in a corresponding function space. In
case of Hilbert space contractions this problem is connected to the theory of
compressed shift operators to which we contribute by providing explicit matrix
representations for such operators. Finally, we apply our results to study the
sensitivity of the stationary states of a classical or quantum Markov chain
with respect to perturbations of the transition matrix.


title: First Bloch eigenvalue in high contrast media

abstract:
  This paper deals with the asymptotic behavior of the first Bloch eigenvalue
in a heterogeneous medium with a high contrast $\ep Y$-periodic conductivity.
When the conductivity is bounded in $L^1$ and the constant of the
Poincar\'e-Wirtinger weighted by the conductivity is very small with respect to
$\ep^{-2}$, the first Bloch eigenvalue converges as $\ep\to 0$ to a limit which
preserves the second-order expansion with respect to the Bloch parameter. In
dimension two the expansion of the limit can be improved until the fourth-order
under the same hypotheses. On the contrary, in dimension three a fibers
reinforced medium combined with a $L^1$-unbounded conductivity leads us to a
discontinuity of the limit first Bloch eigenvalue as the Bloch parameter tends
to zero but remains not orthogonal to the direction of the fibers. Therefore,
the high contrast conductivity of the microstructure induces an anomalous
effect, since for a given low-contrast conductivity the first Bloch eigenvalue
is known to be analytic with respect to the Bloch parameter around zero.


title: New density-independent interactions for nuclear structure calculations

abstract:
  We present a new two-body finite-range and momentum-dependent but
density-independent effective interaction, which can be interpreted as a
regularized zero-range force. We show that no three-body or density-dependent
terms are needed for a correct description of saturation properties in infinite
matter, that is, on the level of low-energy density functional, the physical
three-body effects can be efficiently absorbed in effective two-body terms. The
new interaction gives a very satisfying equation of state of nuclear matter and
opens up extremely interesting perspectives for the mean-field and
beyond-mean-field descriptions of atomic nuclei.


title:
Theory for entanglement of electrons dressed with circularly polarized
  light in Graphene and three-dimensional topological insulators

abstract:
  We have formulated a theory for investigating the conditions which are
required to achieve entangled states of electrons on graphene and
three-dimensional (3D) topological insulators (TIs). We consider the quantum
entanglement of spins by calculating the exchange energy. A gap is opened up at
the Fermi level between the valence and conduction bands in the absence of
doping when graphene as well as 3D TIs are irradiated with circularly-polarized
light. This energy band gap is dependent on the intensity and frequency of the
applied electromagnetic field. The electron-photon coupling also gives rise to
a unique energy dispersion of the dressed states which is different from either
graphene or the conventional two-dimensional electron gas (2DEG). In our
calculations, we obtained the dynamical polarization function for imaginary
frequencies which is then employed to determine the exchange energy. The
polarization function is obtained with the use of both the energy eigenstates
and the overlap of pseudo-spin wave functions. We have concluded that while
doping has a significant influence on the exchange energy and consequently on
the entanglement, the gap of the energy dispersions affects the exchange
slightly, which could be used as a good technique to tune and control
entanglement for quantum information purposes.


title: L\'evy group and density measures

abstract:
  We will deal with finitely additive measures on integers extending the
asymptotic density. We will study their relation to the L\'evy group
$\mathcal{G}$ of permutations of $\mathbb N$. Using a new characterization of
the L\'evy group $\mathcal G$ we will prove that a finitely additive measure
extends density if and only if it is $\mathcal{G}$-invariant.


title: Range of density measures

abstract:
  We investigate some properties of density measures -- finitely additive
measures on the set of natural numbers $\N$ extending asymptotic density. We
introduce a class of density measures, which is defined using cluster points of
the sequence $\big(\frac{A(n)}{n}\big)$ as well as cluster points of some other
similar sequences.
  We obtain range of possible values of density measures for any subset of
$\N$. Our description of this range simplifies the description of Bhashkara Rao
and Bhashkara Rao \cite{brbr} for general finitely additive measures. Also the
values which can be attained by the measures defined in the first part of the
paper are studied.


title:
Secure Degrees of Freedom of K-User Gaussian Interference Channels: A
  Unified View

abstract:
  We determine the exact sum secure degrees of freedom (d.o.f.) of the K-user
Gaussian interference channel. We consider three different secrecy constraints:
1) K-user interference channel with one external eavesdropper (IC-EE), 2)
K-user interference channel with confidential messages (IC-CM), and 3) K-user
interference channel with confidential messages and one external eavesdropper
(IC-CM-EE). We show that for all of these three cases, the exact sum secure
d.o.f. is K(K-1)/(2K-1). We show converses for IC-EE and IC-CM, which imply a
converse for IC-CM-EE. We show achievability for IC-CM-EE, which implies
achievability for IC-EE and IC-CM. We develop the converses by relating the
channel inputs of interfering users to the reliable rates of the interfered
users, and by quantifying the secrecy penalty in terms of the eavesdroppers'
observations. Our achievability uses structured signaling, structured
cooperative jamming, channel prefixing, and asymptotic real interference
alignment. While the traditional interference alignment provides some amount of
secrecy by mixing unintended signals in a smaller sub-space at every receiver,
in order to attain the optimum sum secure d.o.f., we incorporate structured
cooperative jamming into the achievable scheme, and intricately design the
structure of all of the transmitted signals jointly.


title:
Measured Radiation and Background Levels During Transmission of Megawatt
  Electron Beams Through Millimeter Apertures

abstract:
  We report measurements of photon and neutron radiation levels observed while
transmitting a 0.43 MW electron beam through millimeter-sized apertures and
during beam-off, but accelerating gradient RF-on, operation. These measurements
were conducted at the Free-Electron Laser (FEL) facility of the Jefferson
National Accelerator Laboratory (JLab) using a 100 MeV electron beam from an
energy-recovery linear accelerator. The beam was directed successively through
6 mm, 4 mm, and 2 mm diameter apertures of length 127 mm in aluminum at a
maximum current of 4.3 mA (430 kW beam power). This study was conducted to
characterize radiation levels for experiments that need to operate in this
environment, such as the proposed DarkLight Experiment. We find that sustained
transmission of a 430 kW continuous-wave (CW) beam through a 2 mm aperture is
feasible with manageable beam-related backgrounds. We also find that during
beam-off, RF-on operation, multipactoring inside the niobium cavities of the
accelerator cryomodules is the primary source of ambient radiation when the
machine is tuned for 130 MeV operation.


title:
Interpretation of the measurements of total, elastic and diffractive
  cross sections at LHC

abstract:
  Recently at LHC one has obtained measurements of the total, elastic and
diffractive cross sections in pp collisions at very high energy. The total
cross section is in good agreement with predictions based on a leading behavior
\sigma_{tot} (s) \propto (\ln s/s_0)^2, on the other hand the elastic cross
section is lower than most expectations and the diffractive cross section is
higher. It is remarkable that the ratio
  (\sigma_{el} + \sigma_{diff})/\sigma_{tot} calculated combining the results
of the TOTEM and ALICE detectors is 0.495^{+0.05}_{-0.06}, very close to the
maximum theoretically allowed value of 1/2 known as the Miettinen Pumplin
bound. In this work we discuss these results using the frameworks of single and
multi--channel eikonal models, and outline the main difficulties for a
consistent interpretation of the data.


title: The kaon semileptonic form factor with near physical domain wall quarks

abstract:
  We present a new calculation of the K->pi semileptonic form factor at zero
momentum transfer in domain wall lattice QCD with Nf=2+1 dynamical quark
flavours. By using partially twisted boundary conditions we simulate directly
at the phenomenologically relevant point of zero momentum transfer. We perform
a joint analysis for all available ensembles which include three different
lattice spacings (a=0.09-0.14fm), large physical volumes (m_pi*L>3.9) and pion
masses as low as 171 MeV. The comprehensive set of simulation points allows for
a detailed study of systematic effects leading to the prediction
f+(0)=0.9670(20)(+18/-46), where the first error is statistical and the second
error systematic. The result allows us to extract the CKM-matrix element
|Vus|=0.2237(+13/-8) and confirm first-row CKM-unitarity in the Standard Model
at the sub per mille level.


title: Algorithms and differential relations for Belyi functions

abstract:
  A tool package for computing genus 0 Belyi functions is presented, including
simplification routines, computation of moduli fields, decompositions, dessins
d'enfant. The main algorithm for computing the Belyi functions themselves is
based on implied transformations of the hypergeometric differential equation to
Fuchsian equations, preferably with few singular points. This gives interesting
differential relations between polynomial components of a Belyi function.


title: Higgs bosons in particle physics and in condensed matter

abstract:
  Higgs bosons - the amplitude modes - have been experimentally investigated in
condensed matter for many years. An example is superfluid $^3$He-B, where the
broken symmetry leads to 4 Goldstone modes and at least 14 Higgs modes, which
are characterized by angular momentum quantum number $J$ and parity. Based on
the relation $E_{J+}^2+E_{J-}^2=4\Delta^2$ for the energy spectrum of these
modes, Yoichiro Nambu proposed the general sum rule, which relates masses of
Higgs bosons and masses of fermions. If this rule is applicable to Standard
Model, one may expect that the observed Higgs boson with mass $M_{{\rm
H}1}=125$ GeV has a Nambu partner -- the second Higgs boson with mass $M_{{\rm
H}2}=325$ GeV. Together they satisfy the Nambu relation $M_{{\rm H}1}^2 +
M_{{\rm H}2}^2 = 4 M_{\rm top}^2$, where $M_{\rm top}$ is the top quark mass.
Also the properties of the Higgs modes in superfluid $^3$He-A, where the
symmetry breaking is similar to that of the Standard Model, suggest the
possible existence of two electrically charged Higgs particles with masses
$M_{{\rm H}+}=M_{{\rm H}-}\sim 245$ GeV, which together obey the Nambu rule
$M_{{\rm H}+}^2 + M_{{\rm H}-}^2 = 4 M_{\rm top}^2$. A certain excess of events
at 325 GeV and at 245 GeV has been reported in 2011, though not confirmed in
2012 experiments. Besides, we consider the particular relativistic model of top
- quark condensation that suggests the possibility that two twice degenerated
Higgs bosons contribute to the Nambu sum rule. This gives the mass around 210
GeV for the Nambu partner of the 125 GeV Higgs boson. We also discuss the other
possible lessons from the condensed matter to Standard Model, such as hidden
symmetry, where light Higgs emerges as quasi Nambu-Goldstone mode, and the role
of broken time reversal symmetry.


title: Anisotropic Models for Globular Clusters, Galactic Bulges and Dark Halos

abstract:
  Spherical systems with polytropic equations of state are of great interest in
astrophysics. They are widely used to describe neutron stars, red giants, white
dwarfs, brown dwarfs, main sequence stars, galactic halos, and globular
clusters of diverse sizes. In this paper we construct analytically a family of
self-gravitating spherical models in the post-Newtonian approximation of
general relativity. These models present interesting cusps in their density
profiles which are appropriate for the modeling of galaxies and dark matter
halos. The systems described here are anisotropic in the sense that their
equiprobability surfaces in velocity space are nonspherical, leading to an
overabundance of radial or circular orbits, depending on the parameters of the
model under consideration. Among the family of models, we find the
post-Newtonian generalization of the Plummer and Hernquist models. A close
inspection of their equation of state reveals that these solutions interpolate
smoothly between a polytropic sphere in the asymptotic region and an inner core
that resembles an isothermal sphere. Finally, we study the thermodynamics of
these models and argue for their stability.

categories: gr-qc astro-ph.CO astro-ph.GA astro-ph.SR


title: The fate of Lorentz frame in the vicinity of black hole singularity

abstract:
  General Relativity is known to break down at singularities. However, it is
expected that quantum corrections become important when the curvature is of the
order of Planck scale avoiding the singularity. By calculating the effect of
tidal forces on a freely falling inertial frame, and assuming the least
possible size of the frame to be of the Planck length, we show that the Lorentz
frames cease to exist at a finite distance from the singularity. Within that
characteristic radius, one cannot apply General Relativity nor Quantum Field
Theory as we know them today. Additionally we consider other quantum length
scales and impose limits on the distances from the singularity at which those
theories can conceivably be applied within a Lorentz frame.


title:
Kelvin Probe Microscopy and Electronic Transport Measurements in Reduced
  Graphene Oxide Chemical Sensors

abstract:
  Reduced Graphene Oxide (RGO) is an electronically hybrid material that
displays remarkable chemical sensing properties. Here, we present a
quantitative analysis of the chemical gating effects in RGO-based chemical
sensors. The gas sensing devices are patterned in a field-effect transistor
geometry, by dielectrophoretic assembly of RGO platelets between gold
electrodes deposited on SiO2/Si substrates. We show that these sensors display
highly selective and reversible responses to the measured analytes, as well as
fast response and recovery times (tens of seconds). We use combined electronic
transport/Kelvin Probe Microscopy measurements to quantify the amount of charge
transferred to RGO due to chemical doping when the device is exposed to
electron-acceptor (acetone) and electron-donor (ammonia) analytes. We
demonstrate that this method allows us to obtain high-resolution maps of the
surface potential and local charge distribution both before and after chemical
doping, to identify local gate-susceptible areas on the RGO surface, and to
directly extract the contact resistance between the RGO and the metallic
electrodes. The method presented is general, suggesting that these results have
important implications for building graphene and other nanomaterial-based
chemical sensors.


title: "Slicing" the Hopf link

abstract:
  A link in the 3-sphere is called (smoothly) slice if its components bound
disjoint smoothly embedded disks in the 4-ball. More generally, given a
4-manifold M with a distinguished circle in its boundary, a link in the
3-sphere is called M-slice if its components bound in the 4-ball disjoint
embedded copies of M. A 4-manifold M is constructed such that the Borromean
rings are not M-slice but the Hopf link is. This contrasts the classical
link-slice setting where the Hopf link may be thought of "the most non-slice"
link. Further examples and an obstruction for a family of decompositions of the
4-ball are discussed in the context of the A-B slice problem.


title:
Neutral-pion reactions induced by chiral anomaly in strong magnetic
  fields

abstract:
  We investigate decay and production of neutral pions in strong magnetic
fields. In the presence of strong magnetic fields, transition between a neutral
pion and a virtual photon becomes possible through the triangle diagram
relevant for the chiral anomaly. We find that the decay mode of a neutral pion
into two photons cannot persist in the dominant mode in strong magnetic fields,
and that decay into a dilepton instead dominates over the other modes. We also
investigate the effects of magnetic fields on prompt virtual photons created in
ultrarelativistic heavy-ion collisions. There is no anisotropy in the spectrum
at the stage of creation of prompt virtual photons, but after traversing the
strong magnetic field that is induced perpendicularly to the reaction plane,
virtual photons turn into neutral pions, leading to an anisotropic spectrum of
dileptons as a feasible signature in the measurement.


title: CMB Faraday rotation as seen through the Milky Way

abstract:
  Faraday Rotation (FR) of CMB polarization, as measured through mode-coupling
correlations of E and B modes, can be a promising probe of a stochastic
primordial magnetic field (PMF). While the existence of a PMF is still
hypothetical, there will certainly be a contribution to CMB FR from the
magnetic field of the Milky Way. We use existing estimates of the Milky Way
rotation measure (RM) to forecast its detectability with upcoming and future
CMB experiments. We find that the galactic RM will not be seen in polarization
measurements by Planck, but that it will need to be accounted for by CMB
experiments capable of detecting the weak lensing contribution to the B-mode.
We then discuss prospects for constraining the PMF in the presence of FR due to
the galaxy under various assumptions that include partial de-lensing and
partial subtraction of the galactic FR. We find that a realistic future
sub-orbital experiment, covering a patch of the sky near the galactic poles,
can detect a scale-invariant PMF of 0.1 nano-Gauss at better than 95%
confidence level, while a dedicated space-based experiment can detect even
smaller fields.


title: Gauge Field Preheating at the End of Inflation

abstract:
  Here we consider the possibility of preheating the Universe via the
parametric amplification of a massless, U(1) abelian gauge field. We assume
that the gauge field is coupled to the inflaton via a conformal factor with one
free parameter. We present the results of high-resolution three-dimensional
simulations of this model and show this mechanism efficiently preheats the
Universe to a radiation-dominated final state.


title: Ghost-Free Derivative Interactions for a Massive Graviton

abstract:
  If the kinetic interactions of a Lorentz-invariant massive graviton are
Einstein-Hilbert, then the only possible potential terms free from the
Boulware-Deser ghost are those of de Rham, Gabadadze and Tolley (dRGT). We
point out there are other possibilities if the kinetic terms are not required
to be Einstein-Hilbert. We construct pseudo-linear ghost-free potentials, terms
that derive in a natural way from the linear theory. The simplicity of this
approach allows us to construct diffeomorphism non-invariant higher-derivative
interaction terms that do not introduce ghosts. We conjecture that these terms
should have counterparts in the full dRGT theory. These terms would introduce
new free parameters into the theory and may change some of the conclusions
heretofore drawn.


title:
Measurements and simulation of Faraday rotation across the Coma radio
  relic

abstract:
  The aim of this work is to probe the magnetic field properties in relics and
infall regions of galaxy clusters using Faraday Rotation Measures. We present
Very Large Array multi-frequency observations of seven sources in the region
South-West of the Coma cluster, where the infalling group NGC4839 and the relic
1253+275 are located. The Faraday Rotation Measure maps for the observed
sources are derived and analysed to study the magnetic field in the South-West
region of Coma. We discuss how to interpret the data by comparing observed and
mock rotation measures maps that are produced simulating different
3-dimensional magnetic field models. The magnetic field model that gives the
best fit to the Coma central region underestimates the rotation measure in the
South-West region by a factor ~6, and no significant jump in the rotation
measure data is found at the position of the relic. We explore different
possibilities to reconcile observed and mock rotation measure trends, and
conclude that an amplification of the magnetic field along the South-West
sector is the most plausible solution. Our data together with recent X-ray
estimates of the gas density obtained with Suzaku suggest that a magnetic field
amplification by a factor ~3 is required throughout the entire South-West
region in order to reconcile real and mock rotation measures trends. The
magnetic field in the relic region is inferred to be ~2 microG, consistent with
Inverse Compton limits.


title: G-structures and Flavouring non-Abelian T-duality

abstract:
  We examine non-Abelian T-duality on backgrounds preserving N=1 supersymmetry.
We show how backgrounds with SU(3)-structure are mapped to backgrounds with
SU(2)-structure. We provide the transformation rules for the corresponding pure
spinors. We use these techniques to construct new flavoured solutions of type
IIA supergravity.


title: Modeling the HD32297 Debris Disk with Far-IR Herschel Data

abstract:
  HD32297 is a young A-star (~30 Myr) 112 pc away with a bright edge-on debris
disk that has been resolved in scattered light. We observed the HD32297 debris
disk in the far-infrared and sub-millimeter with the Herschel Space Observatory
PACS and SPIRE instruments, populating the spectral energy distribution (SED)
from 63 to 500{\mu}m. We aimed to determine the composition of dust grains in
the HD32297 disk through SED modeling, using geometrical constraints from the
resolved imaging to break degeneracies inherent in SED modeling. We found the
best fitting SED model has 2 components: an outer ring centered around 110 AU,
seen in the scattered light images, and an inner disk near the habitable zone
of the star. The outer disk appears to be composed of grains > 2{\mu}m
consisting of silicates, carbonaceous material, and water ice with an abundance
ratio of 1:2:3 respectively and 90% porosity. These grains appear consistent
with cometary grains, implying the underlying planetesimal population is
dominated by comet-like bodies. We also discuss the 3.7{\sigma} detection of [C
II] emission at 158{\mu}m with the Herschel PACS Spectrometer, making HD32297
one of only a handful of debris disks with circumstellar gas detected.


title: Modelling Element Abundances in Semi-analytic Models of Galaxy Formation

abstract:
  We update the treatment of chemical evolution in the Munich semi-analytic
model, L-GALAXIES. Our new implementation includes delayed enrichment from
stellar winds, supernovae type II (SNe-II) and supernovae type Ia (SNe-Ia), as
well as metallicity-dependent yields and a reformulation of the associated
supernova feedback. Two different sets of SN-II yields and three different
SN-Ia delay-time distributions (DTDs) are considered, and eleven heavy elements
(including O, Mg and Fe) are self-consistently tracked. We compare the results
of this new implementation with data on a) local, star-forming galaxies, b)
Milky Way disc G dwarfs, and c) local, elliptical galaxies. We find that the
z=0 gas-phase mass-metallicity relation is very well reproduced for all forms
of DTD considered, as is the [Fe/H] distribution in the Milky Way disc. The
[O/Fe] distribution in the Milky Way disc is best reproduced when using a DTD
with less than or equal to 50 per cent of SNe-Ia exploding within ~400 Myrs.
Positive slopes in the mass-[alpha/Fe] relations of local ellipticals are also
obtained when using a DTD with such a minor `prompt' component. Alternatively,
metal-rich winds that drive light alpha elements directly out into the
circumgalactic medium also produce positive slopes for all forms of DTD and
SN-II yields considered. Overall, we find that the best model for matching the
wide range of observational data considered here should include a power-law
SN-Ia DTD, SN-II yields that take account of prior mass loss through stellar
winds, and some direct ejection of light alpha elements out of galaxies.


title:
Wind-driven Accretion in Protoplanetary Disks --- II: Radial Dependence
  and Global Picture

abstract:
  Non-ideal magnetohydrodynamical effects play a crucial role in determining
the mechanism and efficiency of angular momentum transport as well as the level
of turbulence in protoplanetary disks (PPDs), which are key to understanding
PPD evolution and planet formation. It was shown in our previous work that at 1
AU, the magnetorotational instability (MRI) is completely suppressed when both
Ohmic resistivity and ambipolar diffusion (AD) are taken into account,
resulting in a laminar flow with accretion driven by magnetocentrifugal wind.
In this work, we study the radial dependence of the laminar wind solution using
local shearing-box simulations. Scaling relation on the angular momentum
transport for the laminar wind is obtained, and we find that the wind-driven
accretion rate can be approximated as
M_dot~0.91x10^(-8)R_AU^(1.21)(B_z/10mG)^(0.93)M_Sun/yr, where B_z is the
strength of the large-scale vertical magnetic field threading the disk. The
result is independent of disk surface density. Four criteria are outlined for
the existence of the laminar wind solution: 1). Ohmic resistivity dominated
midplane region; 2). AD dominated disk upper layer; 3). Presence of (not too
weak) net vertical magnetic flux. 4). Sufficiently well ionized gas beyond disk
surface. All these criteria are likely to be met in the inner region of the
disk from ~0.3 AU to about 5-10 AU for typical PPD accretion rates. Beyond this
radius, angular momentum transport is likely to proceed due to a combination of
the MRI and disk wind, and eventually dominated by the MRI (in the presence of
strong AD) in the outer disk. Our simulation results provide key ingredients
for a new paradigm on the accretion processes in PPDs.


title: Odd parity superconductivity in Weyl semimetals

abstract:
  Unconventional superconducting states of matter are realized in the presence
of strong spin orbit coupling. In particular, non degenerate bands can support
odd parity superconductivity with rich topological content. Here we study
whether this is the case for Weyl semimetals. These are systems whose low
energy sector, in the absence of interactions, is described by linearly
dispersing chiral fermions in three dimensions. The energy spectrum has nodes
at an even number of points in the Brillouin zone. Consequently both intranodal
finite momentum pairing and internodal BCS superconductivity are allowed. For
local attractive interaction the finite momentum pairing state with chiral
p-wave symmetry is found to be most favorable at finite chemical potential. The
state is an analog of the superfluid $^{3}$He A phase, with cooper pairs having
finite center of mass momentum. For chemical potential at the node the state is
preempted by a fully gapped charge density wave. For long range attraction the
BCS state wins out for all values of the chemical potential.


title:
Testing viscous and anisotropic hydrodynamics in an exactly solvable
  case

abstract:
  We exactly solve the one-dimensional boost-invariant Boltzmann equation in
the relaxation time approximation for arbitrary shear viscosity. The results
are compared with the predictions of viscous and anisotropic hydrodynamics.
Studying different non-equilibrium cases and comparing the exact kinetic-theory
results to the second-order viscous hydrodynamics results we find that recent
formulations of second-order viscous hydrodynamics agree better with the exact
solution than the standard Israel-Stewart approach. Additionally, we find that,
given the appropriate connection between the kinetic and anisotropic
hydrodynamics relaxation times, anisotropic hydrodynamics provides a very good
approximation to the exact relaxation time approximation solution.


title: Chern Simons duality with a fundamental boson and fermion

abstract:
  We compute the thermal free energy for all renormalizable Chern Simon
theories coupled to a single fundamental bosonic and fermionic field in the 't
Hooft large N limit. We use our results to conjecture a strong weak coupling
duality invariance for this class of theories. Our conjectured duality reduces
to Giveon Kutasov duality when restricted to {\cal N}=2 supersymmetric theories
and to an earlier conjectured bosonization duality in an appropriate decoupling
limit. Consequently the bosonization duality may be regarded as a deformation
of Giveon Kutasov duality, suggesting that it is true even at large but finite
N.


title: Learning what the Higgs boson is mixed with

abstract:
  The Standard Model Higgs boson may be mixed with another scalar that does not
couple to fermions. The electroweak quantum numbers of such an additional
scalar can be determined by measuring the quartic Higgs-Higgs-vector-vector
couplings, which contribute---along with the coveted triple Higgs coupling---to
double Higgs production in $e^+e^-$ collisions. We show that simultaneous
sensitivity to the quartic Higgs-Higgs-vector-vector coupling and the triple
Higgs coupling can be obtained using measurements of the double Higgs
production cross section at two different e+e- center-of-mass energies.
Kinematic distributions of the two Higgs bosons in the final state could
provide additional discriminating power.


title: Uncovering obscured luminous AGN with WISE

abstract:
  Mateos et al. (2012) presented a highly reliable and efficient mid-infrared
(MIR) colour-based selection technique for luminous active galactic nuclei
(AGN) using the Wide-field Infrared Survey Explorer (WISE) survey. Here we
evaluate the effectiveness of this technique to identify obscured AGN missed in
X-ray surveys. To do so we study the WISE properties of AGN independently
selected in hard X-ray and optical surveys. We use the largest catalogue of 887
[O III]{\lambda}5007-selected type 2 quasars (QSO2s) at z<0.83 in the
literature from the Sloan Digital Sky Survey, and the 258 hard (>4.5 keV)
X-ray-selected AGN from the Bright Ultrahard XMM-Newton Survey (BUXS). The
fraction of SDSS QSO2s in our infrared AGN selection region (wedge) increases
with the AGN luminosity, reaching 66.1+4.5_4.7% at the highest [O III]
luminosities in the sample. This fraction is substantially lower than for the
BUXS type 1 AGN (96.1+3.0_6.3%), but consistent, within the uncertainties, with
that for the BUXS type 2 AGN (75.0+14.1_19.1%) with the same luminosity. The
SDSS QSO2s appear to reside in more luminous (massive) hosts than the BUXS AGN,
due to the tight magnitude limits applied in the SDSS spectroscopic target
selection. Since host galaxy dilution can reduce substantially the
effectiveness of MIR-based techniques, this may explain the lower fraction of
SDSS QSO2s in the WISE AGN wedge. The fraction of SDSS QSO2s identified as
Compton-thick candidates that fall in the wedge is consistent with the fraction
of all SDSS QSO2s in that zone. At the AGN luminosities involved in the
comparison, Compton-thick and Compton-thin SDSS QSO2s have similar WISE colour
distributions. We conclude that at high luminosities and z<1 our MIR technique
is very effective at identifying both Compton-thin and Compton-thick AGN.


title:
Hydrodynamical simulations of a compact source scenario for the Galactic
  Center cloud G2

abstract:
  The origin of the dense gas cloud G2 discovered in the Galactic Center
(Gillessen et al. 2012) is still a debated puzzle. G2 might be a diffuse cloud
or the result of an outflow from an invisible star embedded in it. We present
hydrodynamical simulations of the evolution of different spherically symmetric
winds of a stellar object embedded in G2. We find that the interaction with the
ambient medium and with the extreme gravitational field of the supermassive
black hole in the Galactic Center must be taken into account for such a source
scenario. The thermal pressure of the hot and dense atmosphere confines the
wind, while its ram pressure shapes it via stripping along the orbit, with the
details depending on the wind parameters. Tidal forces squeeze the wind near
pericenter, reducing it to a thin and elongated filament. We also find that in
this scenario most of the Br\gamma\ luminosity is expected to come from the
densest part of the wind, which has a highly filamentary structure with low
filling factor. The observations can be best matched by a mass outflow rate of
Mdot,w=8.8 x 10^{-8} Msun/yr and a wind velocity of vw = 50 km/s. These values
are compatible with those of a young T Tauri star wind, as already suggested by
(Scoville & Burkert 2013).


title: Some aspects of self-duality and generalised BPS theories

abstract:
  If a scalar field theory in (1+1) dimensions possesses soliton solutions
obeying first order BPS equations, then, in general, it is possible to find an
infinite number of related field theories with BPS solitons which obey closely
related BPS equations. We point out that this fact may be understood as a
simple consequence of an appropriately generalised notion of self-duality. We
show that this self-duality framework enables us to generalize to higher
dimensions the construction of new solitons from already known solutions. By
performing simple field transformations our procedure allows us to relate
solitons with different topological properties. We present several interesting
examples of such solitons in two and three dimensions.


title:
Derivation of a Nonlinear Schr\"odinger Equation with a General
  power-type nonlinerity

abstract:
  In this paper we study the derivation of a certain type of NLS from many-body
interactions of bosonic particles. We consider a model with a finite linear
combination of $n$-body interactions, where $n \geq 2$ is an integer. We show
that the $k$-particle marginal density of the BBGKY hierarchy converges when
particle number goes to infinity, and the limit solves a corresponding infinite
Gross-Pitaevskii hierarchy. We prove the uniqueness of factorized solution to
the Gross-Pitaevskii hierarchy based on a priori space time estimates. The
convergence is established by adapting the arguments originated or developed in
\cite{ESY}, \cite{KSS} and \cite{CPquintic}. For the uniqueness part, we expand
the procedure followed in \cite{KM} by introducing a different board game
argument to handle the new contraction operator. This new board game argument
helps us obtain a good estimate on the Duhamel terms. In \cite{KM}, the
relevant space time estimates are assumed to be true, while we give a prove for
it.


title: Enhancing Inflationary Tensor Modes through Spectator Fields

abstract:
  We show that a large contribution to tensor modes during inflation can be
generated by a spectator scalar field with speed of sound lower than unity.


title: The Speed of a Random Walk Excited By Its Recent History

abstract:
  Let $N$ and $M$ be positive integers satisfying $1\le M\le N$, and let
$0<p_0<p_1<1$. Define a process $\{X_n\}_{n=0}^\infty$ on $\mathbb{Z}$ as
follows. At each step, the process jumps either one step to the right or one
step to the left, according to the following mechanism. For the first $N$
steps, the process behaves like a random walk that jumps to the right with
probability $p_0$ and to the left with probability $1-p_0$. At subsequent steps
the jump mechanism is defined as follows: if at least $M$ out of the $N$ most
recent jumps were to the right, then the probability of jumping to the right is
$p_1$; however, if fewer than $M$ out of the $N$ most recent jumps were to the
right, then the probability of jumping to the right is $p_0$. We calculate the
speed of the process. Then we let $N\to\infty$ and $\frac MN\to r\in[0,1]$, and
calculate the limiting speed. More generally, we consider the above questions
for a random walk with a finite number $l$ of threshold levels,
$(M_i,p_i)_{i=1}^l$, above the pre-threshold level $p_0$, as well as for one
model with $l=N$ such thresholds.


title:
Measuring Galaxy Star Formation Rates From Integrated Photometry:
  Insights from Color-Magnitude Diagrams of Resolved Stars

abstract:
  We use empirical star formation histories (SFHs), measured from HST-based
resolved star color-magnitude diagrams, as input into population synthesis
codes to model the broadband spectral energy distributions (SEDs) of ~50 nearby
dwarf galaxies (6.5 < log M/M_* < 8.5, with metallicities ~10% solar). In the
presence of realistic SFHs, we compare the modeled and observed SEDs from the
ultraviolet (UV) through near-infrared (NIR) and assess the reliability of
widely used UV-based star formation rate (SFR) indicators. In the FUV through i
bands, we find that the observed and modeled SEDs are in excellent agreement.
In the Spitzer 3.6micron and 4.5micron bands, we find that modeled SEDs
systematically over-predict observed luminosities by up to ~0.2 dex, depending
on treatment of the TP-AGB stars in the synthesis models. We assess the
reliability of UV luminosity as a SFR indicator, in light of independently
constrained SFHs. We find that fluctuations in the SFHs alone can cause factor
of ~2 variations in the UV luminosities relative to the assumption of a
constant SFH over the past 100 Myr. These variations are not strongly
correlated with UV-optical colors, implying that correcting UV-based SFRs for
the effects of realistic SFHs is difficult using only the broadband SED.
Additionally, for this diverse sample of galaxies, we find that stars older
than 100 Myr can contribute from <5% to100% of the present day UV luminosity,
highlighting the challenges in defining a characteristic star formation
timescale associated with UV emission. We do find a relationship between UV
emission timescale and broadband UV-optical color, though it is different than
predictions based on exponentially declining SFH models. Our findings have
significant implications for the comparison of UV-based SFRs across
low-metallicity populations with diverse SFHs.


title: Entanglement Tsunami: Universal Scaling in Holographic Thermalization

abstract:
  We consider the time evolution of entanglement entropy after a global quench
in a strongly coupled holographic system, whose subsequent equilibration is
described in the gravity dual by the gravitational collapse of a thin shell of
matter resulting in a black hole. In the limit of large regions of
entanglement, the evolution of entanglement entropy is controlled by the
geometry around and inside the event horizon of the black hole, resulting in
regimes of pre-local- equilibration quadratic growth (in time),
post-local-equilibration linear growth, a late-time regime in which the
evolution does not carry any memory of the size and shape of the entangled
region, and a saturation regime with critical behavior resembling those in
continuous phase transitions. Collectively, these regimes suggest a picture of
entanglement growth in which an "entanglement tsunami" carries entanglement
inward from the boundary. We also make a conjecture on the maximal rate of
entanglement growth in relativistic systems.

categories: hep-th cond-mat.stat-mech cond-mat.str-el quant-ph


title:
ORKA, The Golden Kaon Experiment: Precision measurement of K+ ->
  pi+nunubar and other rare processes

abstract:
  ORKA is a proposed experiment to measure the K+ -> pi+nunubar branching ratio
with 5% precision using the Fermilab Main Injector high-intensity proton
source. The detector design is based on the BNL E787/E949 experiments, which
detected seven K+ -> pi+nunubar candidate events. ORKA is expected to acheive
two orders of magnitude improvement in sensitivity relative to the BNL
experiments as a result of enhancements to the beam line and the detector
acceptance. Precise measurement of the K+ -> pi+nunubar branching ratio with
the same level of uncertainty as the well-understood Standard Model prediction
allows for sensitivity to new physics at and beyond the LHC mass scale.
Detector R&D, simulation-based optimization of the experiment design, and
preparation of the experiment location are underway.


title: Explaining ATLAS and CMS Results Within the Reduced Minimal 3-3-1 model

abstract:
  Recently the ATLAS and CMS collaborations announced the discovery of a higgs
particle with a mass of $\sim 125$ GeV. The results are mildly consistent with
the Standard Model Higgs boson. However, the combined data from these
collaborations seem to point to an excess in the $h \rightarrow \gamma \gamma$
channel. In this work we analyze under which conditions this excess may be
plausibly explained within the reduced minimal 3-3-1 model, while being
consistent with bb, WW, ZZ and $\tau^+\tau^-$ channels. Moreover, we derive the
properties of the heavy neutral and the doubly charged scalars predicted by the
model. We then conclude that at a scale of a few TeV, this model provides a
good fit to the ATLAS and CMS signal strength measurements, and therefore
stands as an appealing alternative to the standard model.


title: Exciton Energy Spectra in Two-Dimensional Graphene Derivatives

abstract:
  The energy spectra and wavefunctions of bound excitons in important
two-dimensional (2D) graphene derivatives, i.e., graphyne and graphane, are
found to be strongly modified by quantum confinement, making them qualitatively
different from the usual Rydberg series. However, their parity and optical
selection rules are preserved. Thus a one-parameter modified hydrogenic model
is applied to quantitatively explain the ab initio exciton spectra, and allows
one to extrapolate the electron-hole binding energy from optical spectroscopies
of 2D semiconductors without costly simulations. Meanwhile, our calculated
optical absorption spectrum and enhanced spin singlet-triplet splitting project
graphyne, an allotrope of graphene, as a candidate for intriguing energy and
biomedical applications.


title:
uBoost: A boosting method for producing uniform selection efficiencies
  from multivariate classifiers

abstract:
  The use of multivariate classifiers, especially neural networks and decision
trees, has become commonplace in particle physics. Typically, a series of
classifiers is trained rather than just one to enhance the performance; this is
known as boosting. This paper presents a novel method of boosting that produces
a uniform selection efficiency in a user-defined multivariate space. Such a
technique is ideally suited for amplitude analyses or other situations where
optimizing a single integrated figure of merit is not what is desired.


title: Decrypting the warped black strings

abstract:
  We propose a map for extracting the holographic meaning of the metric for a
class of warped AdS_3 black strings in type IIB supergravity. Our choice of
holographic data is based upon a general prescription due to Papadimitriou.
With this choice, we find a holographic stress tensor that is both symmetric
and conserved, at least when restricted to a particular sector of the theory.
Using the holographic stress tensor, we compute the energy and momentum per
unit length of the black strings, as well as the conformal anomaly, and we show
that the results agree with those previously obtained via covariant methods.


title:
Harnessing Simultaneously the Benefits of UWB and MBWA: A Practical
  Scenario

abstract:
  UWB has a very large bandwidth in a WPAN network, which is best used for
HD-video applications. Meanwhile, MBWA is a WMAN option optimized for
wireless-IP in a fast moving vehicle. In this paper, we propose a practical
engineering scenario that harnesses simultaneously the distinctive feature of
both UWB and MBWA. However, this in-proximity operation of the technologies
will inevitably cause mutual interference to both systems. In light of this, as
a preliminary phase to coexistence, we have derived, under various
circumstances, the maximum interference power limit that needs to be respected
in order to ensure an acceptable system performance as requested by the new
IEEE 802.20 standard.


title:
Violation of Heisenberg's error-disturbance uncertainty relation in
  neutron spin measurements

abstract:
  In its original formulation, Heisenberg's uncertainty principle dealt with
the relationship between the error of a quantum measurement and the thereby
induced disturbance on the measured object. Meanwhile, Heisenberg's heuristic
arguments have turned out to be correct only for special cases. A new
universally valid relation was derived by Ozawa in 2003. Here, we demonstrate
that Ozawa's predictions hold for projective neutron-spin measurements. The
experimental inaccessibility of error and disturbance claimed elsewhere has
been overcome using a tomographic method. By a systematic variation of
experimental parameters in the entire configuration space, the physical
behavior of error and disturbance for projective spin-1/2 measurements is
illustrated comprehensively. The violation of Heisenberg's original relation,
as well as, the validity of Ozawa's relation become manifest. In addition, our
results conclude that the widespread assumption of a reciprocal relation
between error and disturbance is not valid in general.


title:
Joint Spatial Division and Multiplexing: Opportunistic Beamforming and
  User Grouping

abstract:
  Joint Spatial Division and Multiplexing (JSDM) is a recently proposed scheme
to enable massive MIMO like gains and simplified system operations for
Frequency Division Duplexing (FDD) systems. The key idea lies in partitioning
the users into groups with approximately similar covariances, and use a two
stage downlink beamforming: a pre-beamformer that depends on the channel
covariances and minimizes interference across groups and a multiuser MIMO
precoder for the effective channel after pre-beamforming, to counteract
interference within a group. We first focus on the regime of a fixed number of
antennas and large number of users, and show that opportunistic beamforming
with user selection yields significant gain, and thus, channel correlation may
yield a capacity improvement over the uncorrelated "isotropic" channel result
of Sharif and Hassibi. We prove that in the presence of different correlations
among groups, a block diagonalization approach for the design of
pre-beamformers achieves the optimal sum-rate scaling. Next, we consider the
regime of large number of antennas and users, where user selection does not
provide significant gain. Here, we propose a simplified user grouping algorithm
to cluster users into groups when the number of antennas becomes very large, in
a realistic setting where users are randomly distributed and have different
angles of arrival and angular spreads depending on the propagation environment.
Our subsequent analysis leads to a probabilistic scheduling algorithm, where
users within each group are preselected at random based on probabilities
derived from the large system analysis, depending on the fairness criterion.
This is advantageous since only the selected users are required to feedback
their channel state information (CSIT).


title:
Active plasma resonance spectroscopy: A kinetic functional analytic
  description

abstract:
  The term "Active Plasma Resonance Spectroscopy" (APRS) denotes a class of
related techniques which utilize, for diagnostic purposes, the natural ability
of plasmas to resonate on or near the electron plasma frequency $\omega_{\rm
pe}$: A radio frequent signal (in the GHz range) is coupled into the plasma via
an antenna or probe, the spectral response is recorded, and a mathematical
model is used to determine plasma parameters like the electron density or the
electron temperature.
  This manuscript provides a kinetic description of APRS valid for all
pressures and probe geometries. Subject of the description is the interaction
of the probe with the plasma of its influence domain. In a first step, the
kinetic free energy of that domain is established which has a definite time
derivative with respect to the RF power. In the absence of RF excitation, it
assumes the properties of a Lyapunov functional; its minimum provides the
stable equilibrium of the plasma-probe system. Equipped with a scalar product
motivated by the second variation of the free energy, the set of all
perturbations of the equilibrium forms a Hilbert space. The dynamics of the
perturbations can be cast in an evolution equation in that space. The spectral
response function of the plasma-probe system consists of matrix elements of the
resolvent of the dynamical operator. An interpretation in terms of an
equivalent electric circuit model is given and the residual broadening of the
spectrum in the collisionless regime is explained.


title:
Harmony search to solve the container storage problem with different
  container types

abstract:
  This paper presents an adaptation of the harmony search algorithm to solve
the storage allocation problem for inbound and outbound containers. This
problem is studied considering multiple container type (regular, open side,
open top, tank, empty and refrigerated) which lets the situation more
complicated, as various storage constraints appeared. The objective is to find
an optimal container arrangement which respects their departure dates, and
minimize the re-handle operations of containers. The performance of the
proposed approach is verified comparing to the results generated by genetic
algorithm and LIFO algorithm.


title:
Non-linear dimensionality reduction: Riemannian metric estimation and
  the problem of geometric discovery

abstract:
  In recent years, manifold learning has become increasingly popular as a tool
for performing non-linear dimensionality reduction. This has led to the
development of numerous algorithms of varying degrees of complexity that aim to
recover man ifold geometry using either local or global features of the data.
  Building on the Laplacian Eigenmap and Diffusionmaps framework, we propose a
new paradigm that offers a guarantee, under reasonable assumptions, that any
manifo ld learning algorithm will preserve the geometry of a data set. Our
approach is based on augmenting the output of embedding algorithms with
geometric informatio n embodied in the Riemannian metric of the manifold. We
provide an algorithm for estimating the Riemannian metric from data and
demonstrate possible application s of our approach in a variety of examples.


title:
tRNA signatures reveal polyphyletic origins of streamlined SAR11 genomes
  among the alphaproteobacteria

abstract:
  Phylogenomic analyses are subject to bias from compositional convergence and
noise from horizontal gene transfer (HGT). Compositional convergence is a
likely cause of controversy regarding phylogeny of the SAR11 group of
Alphaproteobacteria that have extremely streamlined, A+T-biased genomes. While
careful modeling can reduce artifacts caused by convergence, the most
consistent and robust phylogenetic signal in genomes may lie distributed among
encoded functional features that govern macromolecular interactions. Here we
develop a novel phyloclassification method based on signatures derived from
bioinformatically defined tRNA Class-Informative Features (CIFs). tRNA CIFs are
enriched for features that underlie tRNA-protein interactions. Using a simple
tRNA-CIF-based phyloclassifier, we obtained results consistent with those of
bias-corrected whole proteome phylogenomic studies, rejecting monophyly of
SAR11 and affiliating most strains with Rhizobiales with strong statistical
support. Yet SAR11 and Rickettsiales tRNA genes share distinct patterns of
A+T-richness, as expected from their elevated genomic A+T compositions. Using
conventional supermatrix methods on total tRNA sequence data, we could recover
the artifactual result of a monophyletic SAR11 grouping with Rickettsiales.
Thus tRNA CIF-based phyloclassification is more robust to base content
convergence than supermatrix phylogenomics on whole tRNA sequences. Also, given
the notoriously promiscuous HGT of aminoacyl-tRNA synthetases, tRNA CIF-based
phyloclassification may be relatively robust to HGT of network components. We
describe how unique features of tRNA-protein interaction networks facilitate
the mining of traits governing macromolecular interactions from genomic data,
and discuss why interaction-governing traits may be especially useful to solve
difficult problems in microbial classification and phylogeny.


title: Observation of charm mixing at CDF

abstract:
  We report on the observation of $D^0$--$\bar{D}^0$ oscillations by measuring
the time-dependent ratio of yields for the rare decay $D^0 \rightarrow
K^+\pi^-$ to the favored decay $D^0 \rightarrow K^-\pi^+$ at the Collider
Detector at Fermilab (CDF). Using 9.6 fb$^{-1}$ of integrated luminosity of
$\sqrt{s}$ = 1.96 TeV $p$$\bar{p}$ collisions recorded in the full CDF Run II,
the signals of $7.6 \times 10^6$ $D^0\rightarrow K^-\pi^+$ and $33 \times 10^3$
$D^0\rightarrow K^+\pi^-$ decays are reconstructed in $D^{*}$-tagged events,
with proper decay times between 0.75 and 10 mean $D^0$ lifetimes. We measure
the mixing parameters $x'^2 = (0.08 \pm 0.18)\times 10^{-3}$, $y' = (4.3 \pm
4.3) \times 10^{-3}$, and $R_D = (3.51 \pm 0.35) \times 10^{-3}$. Our results
are consistent with standard model expectations and similar results from
proton-proton collisions and exclude the no-mixing hypothesis with a
significance equivalent to 6.1 standard deviations.


title: Suppression of ferromagnetism in the LaVxCr1-xGe3 system

abstract:
  We report synthesis of hexagonal LaVxCr1-xGe3 (x = 0-0.21, 1.00) single
crystals, and present a systematic study of this series by measurements of
temperature and field dependent magnetic susceptibility, magnetization,
resistivity, and specific heat. Ferromagnetism has been observed for x =
0-0.21, and the system manifests a strong axial anisotropy in its ordered
state. The decrease of the saturated moment and the effective moment per Cr
with the increase of V-concentration suggests this is an itinerant
ferromagnetic system. The Curie temperature declines monotonically as the
V-concentration increases. Single crystalline samples could only be grown for
x-values up to 0.21 for which the transition temperature was suppressed down to
36 K. Although we could not fully suppress TC via V-substitution, for x = 0.16,
we performed magnetization measurements under pressure. The ferromagnetic state
is suppressed under pressure at an initial rate of dTC/dp = -11.7 K/GPa and
vanishes by 3.3 GPa.


title: Maximum Palinstrophy Growth in 2D Incompressible Flows

abstract:
  In this study we investigate vortex structures which lead to the maximum
possible growth of palinstrophy in two-dimensional incompressible flows on a
periodic domain. The issue of palinstrophy growth is related to a broader
research program focusing on extreme amplification of vorticity-related
quantities which may signal singularity formation in different flow models.
Such extreme vortex flows are found systematically via numerical solution of
suitable variational optimization problems. We identify several families of
maximizing solutions parameterized by their palinstrophy, palinstrophy and
energy and palinstrophy and enstrophy. Evidence is shown that some of these
families saturate estimates for the instantaneous rate of growth of
palinstrophy obtained using rigorous methods of mathematical analysis, thereby
demonstrating that this analysis is in fact sharp. In the limit of small
palinstrophies the optimal vortex structures are found analytically, whereas
for large palinstrophies they exhibit a self-similar multipolar structure. It
is also shown that the time evolution obtained using the instantaneously
optimal states with fixed energy and palinstrophy as the initial data saturates
the upper bound for the maximum growth of palinstrophy in finite time. Possible
implications of this finding for the questions concerning extreme behavior of
flows are discussed.


title:
MOST detects transits of HD 97658b, a warm, likely volatile-rich
  super-Earth

abstract:
  Through photometric monitoring of the extended transit window of HD 97658b
with the MOST space telescope, we have found that this exoplanet transits with
an ephemeris consistent with that predicted from radial velocity measurements.
The mid-transit times are $5.6\sigma$ earlier than those of the unverified
transit-like signals reported in 2011, and we find no connection between the
two sets of events. The transit depth together with our determined stellar
radius ($R_\star = 0.703^{+0.039}_{-0.034} R_\odot$) indicates a
2.34$^{+0.18}_{-0.15}$ $R_{\oplus}$ super-Earth. When combined with the radial
velocity determined mass of 7.86 $\pm 0.73$ $M_{\oplus}$, our radius measure
allows us to derive a planet density of 3.44$^{+0.91}_{-0.82}$ g cm$^{-3}$.
Models suggest that a planet with our measured density has a rocky core that is
enveloped in an atmosphere composed of lighter elements. The star of the HD
97658 system is the second brightest known to host a transiting super-Earth,
facilitating follow-up studies of this not easily daunted, warm and likely
volatile-rich exoplanet.


title:
Bulk metallic glass-like structure of small icosahedral metallic
  nanoparticles

abstract:
  We demonstrate a remarkable equivalence in structure measured by total X-ray
scattering methods between very small metallic nanoparticles and bulk metallic
glasses (BMGs), thus connecting two disparate fields, shedding new light on
both. Our results show that for nanoparticle diameters <5 nm the structure of
Ni nanoparticles changes from fcc to the characteristic BMG-like structure,
despite them being formed from a single element, an effect we call
nano-metallic glass (NMG) formation. However, high-resolution TEM images of the
NMG clusters exhibit lattice fringes indicating a locally well-ordered, rather
than glassy, structure. These seemingly contradictory results may be reconciled
by finding a locally ordered structure that is highly isotropic and we show
that local icosahedral packing within 5 atomic shells explains this. Since this
structure is stabilized only in the vicinity of a surface which highlights the
importance of the presence of free volume in BMGs for stabilizing similar local
clusters.


title:
Arithmeticity and topology of smooth actions of higher rank abelian
  groups

abstract:
  We prove that any smooth action of $\mathbb Z^{m-1}, m\ge 3$ on an
$m$-dimensional manifold that preserves a measure such that all non-identity
elements of the suspension have positive entropy is essentially algebraic, i.e.
isomorphic up to a finite permutation to an affine action on the torus or its
factor by $\pm\Id$. Furthermore this isomorphism has nice geometric properties,
in particular, it is smooth in the sense of Whitney on a set whose complement
has arbitrary small measure. We further derive restrictions on topology of
manifolds that may admit such actions, for example, excluding spheres and
obtaining below estimate on the first Betti number in the odd-dimensional case.


title: Unusual Filaments Inside the Umbra

abstract:
  We analyze several unusual filamentary structures, which appeared in the
umbra of one of the sunspots in AR 11302. They do not resemble typical light
bridges, neither in morphology, nor in evolution. We analyze data from SDO/HMI
to investigate their temporal evolution, Hinode/SP for photospheric inversions,
IBIS for chromospheric imaging, and SDO/AIA for the overlying corona.
Photospheric inversions reveal a horizontal, inverse Evershed flow along these
structures, which we call umbral filaments. Chromospheric images show
brightenings and energy dissipation, while coronal images indicate that bright
coronal loops seem to end in these umbral filaments. These rapidly evolving
features do not seem to be common, and are possibly related to the high
flare-productivity of the active region. Their analysis could help to
understand the complex evolution of active regions.


title:
The Moving Group Targets of the SEEDS High-Contrast Imaging Survey of
  Exoplanets and Disks: Results and Observations from the First Three Years

abstract:
  We present results from the first three years of observations of moving group
targets in the SEEDS high-contrast imaging survey of exoplanets and disks using
the Subaru telescope. We achieve typical contrasts of ~10^5 at 1" and ~10^6
beyond 2" around 63 proposed members of nearby kinematic moving groups. We
review each of the kinematic associations to which our targets belong,
concluding that five, \beta Pictoris (~20 Myr), AB Doradus (~100 Myr), Columba
(~30 Myr), Tucana-Horogium (~30 Myr), TW Hydrae (~10 Myr), are sufficiently
well-defined to constrain the ages of individual targets. Somewhat less than
half of our targets are high-probability members of one of these moving groups.
For all of our targets, we combine proposed moving group membership with other
age indicators where available, including Ca II HK emission, X-ray activity,
and rotation period, to produce a posterior probability distribution of age.
SEEDS observations discovered a substellar companion to one of our targets,
\kappa And, a late B star. We do not detect any other substellar companions,
but do find seven new close binary systems, of which one still needs to be
confirmed. A detailed analysis of the statistics of this sample, and of the
companion mass constraints given our age probability distributions and
exoplanet cooling models, will be presented in a forthcoming paper.


title:
A Focused Crawler Combinatory Link and Content Model Based on T-Graph
  Principles

abstract:
  The two significant tasks of a focused Web crawler are finding relevant
topic-specific documents on the Web and analytically prioritizing them for
later effective and reliable download. For the first task, we propose a
sophisticated custom algorithm to fetch and analyze the most effective HTML
structural elements of the page as well as the topical boundary and anchor text
of each unvisited link, based on which the topical focus of an unvisited page
can be predicted and elicited with a high accuracy. Thus, our novel method
uniquely combines both link-based and content-based approaches. For the second
task, we propose a scoring function of the relevant URLs through the use of
T-Graph (Treasure Graph) to assist in prioritizing the unvisited links that
will later be put into the fetching queue. Our Web search system is called the
Treasure-Crawler. This research paper embodies the architectural design of the
Treasure-Crawler system which satisfies the principle requirements of a focused
Web crawler, and asserts the correctness of the system structure including all
its modules through illustrations and by the test results.


title: Measuring Top-Quark Polarization in Top-Pair + Missing Energy Events

abstract:
  The polarization of a top-quark can be sensitive to new physics beyond the
standard model. We propose a novel method to measure top-quark polarization,
based on the charged lepton energy fraction in top-quark decay, and illustrate
the method with a detailed simulation of top-quark pairs produced in
supersymmetric top squark pair production. We show that the lepton energy ratio
distribution that we define is very sensitive to the top-quark polarization but
insensitive to the precise measurement of the top-quark energy.


title: A charged particle Talbot-Lau interferometer and magnetic field sensing

abstract:
  We present the first demonstration of a three grating Talbot-Lau
interferometer for electrons. As a proof of principle, the interferometer is
used to measure magnetic fields. The device is similar to the classical Moire
deflectometer. The possibility to extend this work to build a scaled-up charged
particle deflectometer or interferometer for sensitive magnetic field sensing
is indicated.


title:
Fundamental quantum interferometry bound for the squeezed-light-enhanced
  gravitational-wave detector GEO600

abstract:
  The fundamental quantum interferometry bound limits the sensitivity of an
interferometer for a given total rate of photons and for a given decoherence
rate inside the measurement device.We theoretically show that the recently
reported quantum-noise limited sensitivity of the squeezed-light-enhanced
gravitational-wave detector GEO600 is exceedingly close to this bound, given
the present amount of optical loss. Furthermore, our result proves that the
employed combination of a bright coherent state and a squeezed vacuum state is
generally the optimum practical approach for phase estimation with high
precision on absolute scales. Based on our analysis we conclude that neither
the application of Fock states nor N00N states or any other sophisticated
nonclassical quantum states would have yielded an appreciably higher
quantum-noise limited sensitivity.


title:
Partial difference equations over compact Abelian groups, I: modules of
  solutions

abstract:
  Consider a compact Abelian group $Z$ and closed subgroups $U_1$, \ldots, $U_k
\leq Z$. Let $\mathbb{T} := \mathbb{R}/\mathbb{Z}$. This paper examines two
kinds of functional equation for measurable functions $Z\to \mathbb{T}$.
  First, given $f:Z\to \mathbb{T}$ and $w \in Z$, the resulting differenced
function is \[d_wf(z) := f(z-w) - f(z).\] In this notation, we study solutions
to the system of difference equations \[d_{u_1}\cdots d_{u_k}f \equiv 0 \quad
\forall u_1 \in U_1,\ u_2 \in U_2,\ \ldots\ u_k \in U_k.\] Second, we study
tuples of measurable functions $f_i:Z\to \mathbb{T}$ such that $f_i$ is
invariant under translation by $U_i$ and also \[f_1 + \cdots + f_k = 0.\]
  For these equations, the solutions form a subgroup of $\mathcal{F}(Z)$ or
$\mathcal{F}(Z)^k$, where $\mathcal{F}(Z)$ is the group of measurable functions
$Z\to \mathbb{T}$ modulo Haar-a.e. equality. The subgroup of solutions is
closed under convergence in probability and is globally invariant under
rotations of $Z$, so it is a complete metrizable $Z$-module. We will give a
recursive description of the structure of this $Z$-module relative to the
solution-modules of lower-order equations of the same kind.
  These results are obtained as applications of an abstract theory of a special
class of $Z$-modules. Most of our work will go into showing that this class of
modules is closed under various natural operations. Knowing that, the above
descriptions follow as easy consequences.
  Partial difference equations of the above kind can be seen as an extremal
version of the inverse problem for the higher-dimensional, directional analogs
of Gowers' uniformity norms. Our methods also give some information about the
`stability' version of this inverse problem, which concerns functions whose
Gowers norm is sufficiently close to being maximal.


title: Observing single quantum trajectories of a superconducting qubit

abstract:
  The length of time that a quantum system can exist in a superposition state
is determined by how strongly it interacts with its environment. This
interaction entangles the quantum state with the inherent fluctuations of the
environment. If these fluctuations are not measured, the environment can be
viewed as a source of noise, causing random evolution of the quantum system
from an initially pure state into a statistical mixture-a process known as
decoherence. However, by accurately measuring the environment in real time, the
quantum system can be maintained in a pure state and its time evolution
described by a quantum trajectory conditioned on the measurement outcome. We
employ weak measurements to monitor a microwave cavity embedding a
superconducting qubit and track the individual quantum trajectories of the
system. In this architecture, the environment is dominated by the fluctuations
of a single electromagnetic mode of the cavity. Using a near-quantum-limited
parametric amplifier, we selectively measure either the phase or amplitude of
the cavity field, and thereby confine trajectories to either the equator or a
meridian of the Bloch sphere. We perform quantum state tomography at discrete
times along the trajectory to verify that we have faithfully tracked the state
of the quantum system as it diffuses on the surface of the Bloch sphere. Our
results demonstrate that decoherence can be mitigated by environmental
monitoring and validate the foundations of quantum feedback approaches based on
Bayesian statistics. Moreover, our experiments suggest a new route for
implementing what Schrodinger termed "quantum steering"-harnessing action at a
distance to manipulate quantum states via measurement.

categories: quant-ph cond-mat.mes-hall cond-mat.supr-con physics.atom-ph


title:
A methodology for detecting and exploring non-convulsive seizures in
  patients with SAH

abstract:
  A methodology for understanding and de- tecting nonconvulsive seizures in
individuals with sub- arachnoid hemorrhage is introduced. Specifically, begin-
ning with an EEG signal, the power spectrum is esti- mated yielding a
multivariate time series which is then ana- lyzed using empirical orthogonal
functional analysis. This methodology allows for easy identification and
observation of seizures that are otherwise only identifiable though ex- pert
analysis of the raw EEG.


title:
Accuracy of Range-Based Cooperative Localization in Wireless Sensor
  Networks: A Lower Bound Analysis

abstract:
  Accurate location information is essential for many wireless sensor network
(WSN) applications. A location-aware WSN generally includes two types of nodes:
sensors whose locations to be determined and anchors whose locations are known
a priori. For range-based localization, sensors' locations are deduced from
anchor-to-sensor and sensor-to-sensor range measurements. Localization accuracy
depends on the network parameters such as network connectivity and size. This
paper provides a generalized theory that quantitatively characterizes such
relation between network parameters and localization accuracy. We use the
average degree as a connectivity metric and use geometric dilution of precision
(DOP), equivalent to the Cramer-Rao bound, to quantify localization accuracy.
We prove a novel lower bound on expectation of average geometric DOP
(LB-E-AGDOP) and derives a closed-form formula that relates LB-E-AGDOP to only
three parameters: average anchor degree, average sensor degree, and number of
sensor nodes. The formula shows that localization accuracy is approximately
inversely proportional to the average degree, and a higher ratio of average
anchor degree to average sensor degree yields better localization accuracy.
Furthermore, the paper demonstrates a strong connection between LB-E-AGDOP and
the best achievable accuracy. Finally, we validate the theory via numerical
simulations with three different random graph models.


title:
Energy Spectrum of Ultra-High Energy Cosmic Rays Observed with the
  Telescope Array Using a Hybrid Technique

abstract:
  We measure the spectrum of cosmic rays with energies greater than $10^{18.2}$
eV with the Fluorescence Detectors (FDs) and the Surface Detectors (SDs) of the
Telescope Array Experiment using the data taken in our first 2.3-year
observation from May 27 2008 to September 7 2010. A hybrid air shower
reconstruction technique is employed to improve accuracies in determination of
arrival directions and primary energies of cosmic rays using both FD and SD
data. The energy spectrum presented here is in agreement with our previously
published spectra and the HiRes results.


title:
Influence of generalized focusing of few-cycle Gaussian pulses in
  attosecond pulse generation

abstract:
  In contrast to the case of quasi-monochromatic waves, a focused optical pulse
in the few-cycle limit may exhibit two independent curved wavefronts,
associated with phase and group retardations, respectively. Focusing optical
elements will generally affect these two wavefronts differently, thus leading
to very different behavior of the pulse near focus. As limiting cases, we
consider an ideal diffractive lens introducing only phase retardations and a
perfect non-dispersive refractive lens (or a curved mirror) introducing equal
phase and group retardations. We study the resulting diffraction effects on the
pulse, finding both strong deformations of the pulse shape and shifts in the
spectrum. We then show how important these effects can be in highly nonlinear
optics, by studying their role in attosecond pulse generation. In particular,
the focusing effects are found to affect substantially the generation of
isolated attosecond pulses in gases from few-cycle fundamental optical fields.


title: Phase Diagram of a Three Orbital Model for the high-T$_c$ cuprates

abstract:
  We study the phase diagram of an effective three orbital model of the
cuprates using Variational Monte-Carlo calculations (VMC) on asymptotically
large lattices and exact diagonalization on a 24-site cluster. States with
ordered orbital current loops (LC), itinerant Anti-ferromagnetism (AFM), d-wave
superconductivity (SC), and the Fermi-liquid (FL) are investigated using
appropriate Slater determinants refined by Jastrow functions for on-site and
inter-site correlations. We find an LC state stable in the thermodynamic limit
for a range of parameters compatible with the Fermi surface of a typical hole
doped superconductors provided the transfer integrals between the oxygen atoms
have signs determined by the effects of indirect transfer through the Cu-4s
orbitals as suggested by O.K. Andersen. The results of the calculations are
that this phase gives way at lower dopings to an AFM phase and at larger
copings to a SC phase followed by a FL phase.


title: An abstract result on Cohen strongly summing operators

abstract:
  We present an abstract result that characterizes the coincidence of certain
classes of linear operators with the class of Cohen strongly summing linear
operators. Our argument is extended to multilinear operators and, as a
consequence, we establish a few alternative characterizations for the class of
Cohen strongly summing multilinear operators.


title: The Different Varieties of the Suyama-Yamaguchi Consistency Relation

abstract:
  We present the different consistency relations that can be seen as variations
of the well known Suyama-Yamaguchi (SY) consistency relation \tau_{NL}
\geqslant (\frac{6}{5} f_{NL})^2, the latter involving the levels of
non-gaussianity f_{NL} and \tau_{NL} in the primordial curvature perturbation
\zeta, they being scale-invariant. We explicitly state under which conditions
the SY consistency relation has been claimed to hold in its different varieties
(implicitly) presented in the literature since its inception back in 2008; as a
result, we show for the first time that the variety \tau_{NL} ({\bf k}_1, {\bf
k}_1) \geqslant (\frac{6}{5} f_{NL} ({\bf k}_1))^2, which we call "the fifth
variety", is always satisfied even when there is strong scale-dependence and
high levels of statistical anisotropy as long as statistical homogeneity holds:
thus, an observed violation of this specific variety would prevent the
comparison between theory and observation, shaking this way the foundations of
cosmology as a science.


title: Integrated spatial multiplexing of heralded single photon sources

abstract:
  The non-deterministic nature of photon sources is a key limitation for single
photon quantum processors. Spatial multiplexing overcomes this by enhancing the
heralded single photon yield without enhancing the output noise. Here the
intrinsic statistical limit of an individual source is surpassed by spatially
multiplexing two monolithic silicon correlated photon pair sources,
demonstrating a 62.4% increase in the heralded single photon output without an
increase in unwanted multi-pair generation. We further demonstrate the
scalability of this scheme by multiplexing photons generated in two waveguides
pumped via an integrated coupler with a 63.1% increase in the heralded photon
rate. This demonstration paves the way for a scalable architecture for
multiplexing many photon sources in a compact integrated platform and achieving
efficient two photon interference, required at the core of optical quantum
computing and quantum communication protocols.


title:
The longitudinal response function of the deuteron in chiral effective
  field theory

abstract:
  We use chiral effective field theory (EFT) to make predictions for the
longitudinal electromagnetic response function of the deuteron, f_L, which is
measured in d(e,e'N) reactions. In this case the impulse approximation gives
the full chiral EFT result up to corrections that are of O(P^4) relative to
leading. By varying the cutoff in the chiral EFT calculations between 0.6 and 1
GeV we conclude that the calculation is accurate to better than 10 % for values
of q^2 within 4 fm^{-2} of the quasi-free peak, up to final-state energies
E_{np}=60 MeV. In these regions chiral EFT is in reasonable agreement with
predictions for f_L obtained using the Bonn potential. We also find good
agreement with existing experimental data on f_L, albeit in a more restricted
kinematic domain.


title:
Rigidity of complete entire self-shrinking solutions to Kahler-Ricci
  flow

abstract:
  We show that every complete entire self-shrinking solution on complex
Euclidean space to the Kahler-Ricci flow must be generated from a quadratic
potential.


title: Holographic meson mass splitting in the Nuclear Matter

abstract:
  We study the holographic light meson spectra and their mass splitting in the
nuclear medium. In order to describe the nuclear matter, we take into account
the thermal charged AdS geometry with two flavor charges, which can be
reinterpreted as the number densities of proton and neutron after some field
redefinitions. We show that the meson mass splitting occurs when there exists
the density difference between proton and neutron. Depending on the flavor
charge, the mass of the positively (negatively) charged meson increases
(decreases) as the density difference increases, whereas the neutral meson mass
is independent of the density difference. In the regime of the large nucleon
density with a relatively large number difference between proton and neutron,
we find that negatively charged pion becomes massless in the nuclear medium, so
the pion condensate can occur. We also investigate the binding energy of a
heavy quarkonium in the nuclear medium, in which the binding energy of a heavy
quarkonium becomes weaker as the density difference increases.


title: Propagation of Chaos for a Thermostated Kinetic Model

abstract:
  We consider a system of N point particles moving on a d-dimensional torus.
Each particle is subject to a uniform field E and random speed conserving
collisions. This model is a variant of the Drude-Lorentz model of electrical
conduction. In order to avoid heating by the external field, the particles also
interact with a Gaussian thermostat which keeps the total kinetic energy of the
system constant. The thermostat induces a mean-field type of interaction
between the particles. Here we prove that, starting from a product measure, in
the large N limit, the one particle velocity distribution satisfies a self
consistent Vlasov-Boltzmann equation.. This is a consequence of "propagation of
chaos", which we also prove for this model.


title: Neutrino Masses and Higgs Vacuum Stability

abstract:
  The Standard Model electroweak vacuum has been found to be metastable, with
the true stable vacuum given by a large, phenomenologically unacceptable vacuum
expectation value $\approx M_{P}$. Moreover, it may be unstable in an
inflationary universe. Motivated by the necessity of physics beyond the
Standard Model and to accommodate non-zero neutrino masses, we investigate
vacuum stability within type-II seesaw and left-right symmetric models. Our
analysis is performed by solving the renormalisation group equations, carefully
taking into account the relevant threshold corrections. We demonstrate that a
phenomenologically viable left-right symmetric model can be constructed by
matching it with the SM at one-loop. In both models we demonstrate the
existence of a large area of parameter space where the Higgs vacuum is
absolutely stable.


title: Adjusting for Treatment Effects in Studies of Quantitative Traits

abstract:
  A population-based study of a quantitative trait, e.g. Blood Pressure(BP) may
be seriously compromised when the trait is subject to the effects of a
treatment. Without appropriate corrections this can lead to considerable
reduction of statistical power. Here we demonestrate this in the scenario of
QTL mapping through Single-Marker Analysis. The data are simulated from a
normal mixtrure for different values of allele frequencies, separation between
normal populations and Linkage Disequilibrium, and several methods of
correction are compared to check which can best compensate for the loss of
power if treatment effects are ignored. In one of these methods, underlying BPs
are approximated by subtracting an estimate of mean value of medicine effect
from obsereved BPs in treated subjects. We domonestrate the efficacy of this
method throughout different choices of parameters. Finally to account for
quantitative traits that follow non-normal distributions, data are simulated
from lognormal mixtures similarly and Kruskal-Wallis test is used to obtain
estimates of powers for different methods of analysis.


title:
Adapting the Interrelated Two-way Clustering method for Quantitative
  Structure-Activity Relationship (QSAR) Modeling of a Diverse Set of Chemical
  Compounds

abstract:
  Interrelated Two-way Clustering (ITC) is an unsupervised clustering method
developed to divide samples into two groups in gene expression data obtained
through microarrays, selecting important genes simultaneously in the process.
This has been found to be a better approach than conventional clustering
methods like K-means or self-organizing map for the scenarios when number of
samples much smaller than number of variables (n<<p). In this paper we used the
ITC approach for classification of a diverse set of 508 chemicals regarding
mutagenicity. A large number of topological indices (TIs), 3-dimensional, and
quantum chemical descriptors, as well as atom pairs (APs) have been used as
explanatory variables. In this paper, ITC has been used only for predictor
selection, after which ridge regression is employed to build the final
predictive model. The proper leave-one-out (LOO) method of cross-validation in
this scenario is to take as holdout each of the 508 compounds before predictor
thinning and compare the predicted values with the experimental data. ITC based
results obtained here are comparable to those developed earlier.


title: Rational associahedra and noncrossing partitions

abstract:
  Each positive rational number x>0 can be written uniquely as x=a/(b-a) for
coprime positive integers 0<a<b. We will identify x with the pair (a,b). In
this paper we define for each positive rational x>0 a simplicial complex
\Ass(x)=\Ass(a,b) called the {\sf rational associahedron}. It is a pure
simplicial complex of dimension a-2, and its maximal faces are counted by the
{\sf rational Catalan number} \Cat(x)=\Cat(a,b):=\frac{(a+b-1)!}{a!\,b!}. The
cases (a,b)=(n,n+1) and (a,b)=(n,kn+1) recover the classical associahedron and
its "Fuss-Catalan" generalization studied by Athanasiadis-Tzanaki and
Fomin-Reading. We prove that \Ass(a,b) is shellable and give nice product
formulas for its h-vector (the {\sf rational Narayana numbers}) and f-vector
(the {\sf rational Kirkman numbers}). We define \Ass(a,b) via {\sf rational
Dyck paths}: lattice paths from (0,0) to (b,a) staying above the line y =
\frac{a}{b}x. We also use rational Dyck paths to define a rational
generalization of noncrossing perfect matchings of [2n]. In the case (a,b) =
(n, mn+1), our construction produces the noncrossing partitions of [(m+1)n] in
which each block has size m+1.


title: Flat band states: disorder and nonlinearity

abstract:
  We study the critical behaviour of Anderson localized modes near intersecting
flat and dispersive bands in the quasi-one-dimensional diamond ladder with weak
diagonal disorder $W$. The localization length $\xi$ of the flat band states
scales with disorder as $\xi \sim W^{-\gamma}$, with $\gamma \approx 1.3$, in
contrast to the dispersive bands with $\gamma =2$. A small fraction of
dispersive modes mixed with the flat band states is responsible for the unusual
scaling. Anderson localization is therefore controlled by two different length
scales. Nonlinearity can produce qualitatively different wave spreading
regimes, from enhanced expansion to resonant tunneling and self-trapping.


title: The Stokes Groupoids

abstract:
  We construct and describe a family of groupoids over complex curves which
serve as the universal domains of definition for solutions to linear ordinary
differential equations with singularities. As a consequence, we obtain a
direct, functorial method for resumming formal solutions to such equations.


title: Twisting loops and global momentum non-conservation in Relative Locality

abstract:
  Recent work in Relative Locality has shown that the theory allows for a
solution of an on-shell causal loop. We show that the theory contains a
different type of a loop in which locally momenta are conserved, but there is
no global momentum conservation. Thus a freely propagating particle can decay
into two particles, which later recombine to give a particle with momentum and
mass different than the original one.


title: Cosmological dynamics in f(R) gravity

abstract:
  In this paper, we study the cosmological viability conditions, the
phase-space dynamics, and the cosmological evolution of f(R) gravity. In
contrast to most previous works in the literature, which analyzed the
background dynamics of f(R) gravity by means of a dynamical system, we proceed
by focusing on the equivalent scalar field description of the theory, which we
believe is a more intuitive way of treating the problem. In order to study how
the physical solutions evolve in f(R) cosmology, we explore the cosmological
dynamics of a range of f(R) models, including models that yield a large
hierarchy of scales and are singularity free. We present generic features of
the phase-space dynamics in f(R) cosmology. We study the global structure of
the phase space in f(R) gravity by compactifying the infinite phase space into
a finite space via the Poincare transformation. On the expansion branch of the
phase space, the constraint surface has a repeller and a de Sitter attractor;
while on the contraction branch, the constraint surface has an attractor and a
de Sitter repeller. Generally, the phase currents originate from the repeller
and terminate at the corresponding attractor in each space. The trajectories
between the repeller and the attractor in the presence of matter density are
different from those in the vacuum case. The phase analysis techniques
developed in this paper are very general, and can be applied to other similar
dynamical systems.


title:
Symplectormophism groups of non-compact manifolds, orbifold balls, and a
  space of Lagrangians

abstract:
  We establish connections between contact isometry groups of certain contact
manifolds and compactly supported symplectomorphism groups of their
symplectizations. We apply these results to investigate the space of symplectic
embeddings of balls with a single conical singularity at the origin. Using
similar ideas, we also prove the longstanding expected result that the space of
Lagrangian $\RR P^2$ in $T^*\RR P^2$ is weakly contractible.


title:
Calculating Extra (Quasi)Moduli on the Abrikosov-Nielsen-Olesen string
  with Spin-Orbit Interaction

abstract:
  Using a representative set of parameters we numerically calculate the
low-energy Lagrangian on the world sheet of the Abrikosov-Nielsen-Olesen string
in a model in which it acquires rotational (quasi)moduli. The bulk model is
deformed by a spin-orbit interaction generating a number of "entangled" terms
on the string world sheet.


title: Quantum symmetric states on free product C*-algebras

abstract:
  We introduce symmetric states and quantum symmetric states on universal
unital free product C*-algebras an arbitrary unital C*-algebra A with itself
infinitely many times, as a generalization of the notions of exchangeable and
quantum exchangeable random variables. We prove existence of conditional
expectations onto tail algebras in various settings and we define a natural
C*-subalgebra of the tail algebra, called the tail C*-algebra. Extending and
building on the proof of the noncommutative de Finetti theorem of Koestler and
Speicher, we prove a de Finetti type theorem that characterizes quantum
symmetric states in terms of amalgamated free products over the tail
C*-algebra, and we provide a convenient description of the set of all quantum
symmetric states on the free product C*-algebra in terms of C*-algebras
generated by homomorphic images of A and the tail C*-algebra. This description
allows a characterization of the extreme quantum symmetric states. Similar
results are proved for the subset of tracial quantum symmetric states, though
in terms of von Neumann algebras and normal conditional expectations. The
central quantum symmetric states are those for which the tail algebra is in the
center of the von Neumann algebra, and we show that the central quantum
symmetric states form a Choquet simplex whose extreme points are the free
product states, while the tracial central quantum symmetric states form a
Choquet simplex whose extreme points are the free product traces.


title: A Note on Cyclic Codes from APN Functions

abstract:
  Cyclic codes, as linear block error-correcting codes in coding theory, play a
vital role and have wide applications. Ding in \cite{D} constructed a number of
classes of cyclic codes from almost perfect nonlinear (APN) functions and
planar functions over finite fields and presented ten open problems on cyclic
codes from highly nonlinear functions. In this paper, we consider two open
problems involving the inverse APN functions $f(x)=x^{q^m-2}$ and the Dobbertin
APN function $f(x)=x^{2^{4i}+2^{3i}+2^{2i}+2^{i}-1}$. From the calculation of
linear spans and the minimal polynomials of two sequences generated by these
two classes of APN functions, the dimensions of the corresponding cyclic codes
are determined and lower bounds on the minimum weight of these cyclic codes are
presented. Actually, we present a framework for the minimal polynomial and
linear span of the sequence $s^{\infty}$ defined by $s_t=Tr((1+\alpha^t)^e)$,
where $\alpha$ is a primitive element in $GF(q)$. These techniques can also be
applied into other open problems in \cite{D}.


title: Intrinsic Anomalous Hall Effect in Magneto-Chiral States

abstract:
  We show that a finite Hall effect in zero applied magnetic field occurs for
partially filled bands in certain time-reversal violating states with zero net
flux per unit-cell. These states are the Magneto-chiral states with parameters
in the effective one-particle Hamiltonian such that they do not satisfy the
Haldane-type constraints for topological electronic states. The results extend
an earlier discussion of the Kerr effect observed in the cuprates but may be
applicable to other experimental situations.


title: What exactly are the properties of scale-free and other networks?

abstract:
  The concept of scale-free networks has been widely applied across natural and
physical sciences. Many claims are made about the properties of these networks,
even though the concept of scale-free is often vaguely defined. We present
tools and procedures to analyse the statistical properties of networks defined
by arbitrary degree distributions and other constraints. Doing so reveals the
highly likely properties, and some unrecognised richness, of scale-free
networks, and casts doubt on some previously claimed properties being due to a
scale-free characteristic.

categories: nlin.AO cs.SI physics.comp-ph physics.soc-ph


title:
A new example of a generic 2-distribution on a 5-manifold with large
  symmetry algebra

abstract:
  We discover a new example of a generic rank 2-distribution on a 5-manifold
with a 6-dimensional transitive symmetry algebra, which is not present in
Cartan's classical five variables paper. It corresponds to the Monge equation
z' = y + (y'')^(1/3) with invariant quartic having root type [4], and a
6-dimensional non-solvable symmetry algebra isomorphic to the semidirect
product of sl(2) and the 3-dimensional Heisenberg algebra.


title: Exact-diagonalization study of exciton condensation in electron bilayers

abstract:
  We report on small-cluster exact-diagonalization calculations which prove the
formation of electron-hole pairs (excitons) as prerequisite for spontaneous
interlayer phase coherence in bilayer systems described by the extended
Falicov-Kimball model. Evaluating the anomalous Green's function and momentum
distribution function of the pairs, and thereby analyzing the dependence of the
exciton binding energy, condensation amplitude, and coherence length on the
Coulomb interaction strength, we demonstrate a crossover between a BCS-like
electron-hole pairing transition and a Bose-Einstein condensation of tightly
bound preformed excitons. We furthermore show that a mass imbalance between
electrons and holes tends to suppress the condensation of excitons.


title: Role of pairing in the description of Giant Monopole Resonances

abstract:
  We compare the results obtained in the framework of the quasiparticle random
phase approximation (QRPA) on top of a Hartree-Fock-Bogoliubov (HFB) with the
most recent experiments on giant monopole resonances in Pb, Sn, Zr, Sm, Mo and
Cd. Our calculations are fully self consistent and the density dependence of
pairing interactions is, for the first time in this framework, properly taken
into account. In the particle-hole (ph) channel we employ different Skyrme
functionals (SLy5, SkM* and Skxs20) while in the particle-particle (pp) channel
we make use of density dependent contact interactions. We introduce in the pp
channel the recently proposed contact interactions which take into account the
neutron-proton asymmetry. We find that no single parametrization is able to
reproduce with sufficient accuracy all the nuclei. Since about two-thirds of
the nuclei under investigation are better explained with a soft
parametrization, this tends to suggest that the currently accepted picture for
the incompressibility might require modifications.