title:
Spatially unassociated galaxies contribute significantly to the blended
  submillimetre galaxy population: predictions for follow-up observations of
  ALMA sources

abstract:
  There is anecdotal evidence that spatially and physically unassociated
galaxies blended into a single submillimetre (submm) source contribute to the
submm galaxy (SMG) population. This work is the first to theoretically predict
the number counts of such sources. We generate mock SMG catalogues using
lightcones derived from the Bolshoi cosmological simulation; to assign submm
flux densities to the mock galaxies, we use a fitting function previously
derived from the results of dust radiative transfer performed on hydrodynamical
simulations of isolated disc and merging galaxies. We then calculate submm
number counts for different beam sizes and without blending. We predict that >
~50 per cent of blended SMGs have at least one spatially unassociated component
with S_850 > 1 mJy. For a 15-arcsec beam, blends of >2 galaxies in which at
least one component is spatially unassociated dominate the blended sources with
total S_850 > ~3 mJy. The distribution of the redshift separations amongst the
components is strongly bimodal. The typical redshift separation of spatially
unassociated blended sources is ~1. Our predictions for the contributions of
spatially unassociated components and the distribution of redshift separations
are not testable with currently available data, but they will be easily tested
once sufficiently accurate redshifts for the individual subcomponents (resolved
by, e.g., ALMA) of a sufficient number of single-dish-detected blended SMGs are
available.


title: The Late-Time Rebrightening of Type Ia SN 2005gj in the Mid-Infrared

abstract:
  A growing number of observations reveal a subset of Type Ia supernovae
undergoing circumstellar interaction (SNe Ia-CSM). We present unpublished
archival Spitzer Space Telescope data on SNe Ia-CSM 2002ic and 2005gj obtained
> 1300 and 500 days post-discovery, respectively. Both SNe show evidence for
late-time mid-infrared (mid-IR) emission from warm dust. The dust parameters
are most consistent with a pre-existing dust shell that lies beyond the
forward-shock radius, most likely radiatively heated by optical and X-ray
emission continuously generated by late-time CSM interaction. In the case of SN
2005gj, the mid-IR luminosity more than doubles after 1 year post-discovery.
While we are not aware of any late-time optical-wavelength observations at
these epochs, we attribute this rebrightening to renewed shock interaction with
a dense circumstellar shell.


title: Higgs Decays as a Window into the Dark Sector

abstract:
  A light vector boson, Z_d, associated with a "dark sector" U(1)_d gauge group
has been introduced to explain certain astrophysical observations as well as
low energy laboratory anomalies. In such models, the Higgs boson may decay into
X+Z_d, where X=Z, Z_d or \gamma. Here, we provide estimates of those decay
rates as functions of the Z_d coupling through either mass-mixing (e.g. via an
enlarged Higgs mechanism) or through heavy new fermion loops and examine the
implied LHC phenomenology. Our studies focus on the higher m_{Z_d} case, >
several GeV, where the rates are potentially measurable at the LHC, for
interesting regions of parameter spaces, at a level complementary to low energy
experimental searches for the Z_d. We also show how measurement of the Z_d
polarization (longitudinal versus transverse) can be used to distinguish the
physics underlying these rare decays.


title: Geolocating the Higgs Boson Candidate at the LHC

abstract:
  The latest results from the ATLAS and CMS experiments at the CERN Large
Hadron Collider (LHC) unequivocally confirm the existence of a resonance, $X$,
with mass near 125 GeV which could be the Higgs boson of the Standard Model.
Measuring the properties (quantum numbers and couplings) of this resonance is
of paramount importance. Initial analyses by the LHC collaborations disfavor
specific alternative benchmark hypotheses, e.g. pure pseudoscalars or
gravitons. However, this is just the first step in a long-term program of
detailed measurements. We consider the most general set of operators in the
decay channels $X \to ZZ$, $WW$, $Z\gamma$, $\gamma\gamma$ and derive the
constraint implied by the measured rate. This allows us to provide a useful
parametrization of the orthogonal independent Higgs coupling degrees of freedom
as coordinates on a suitably defined sphere.


title:
Further Evidence for a Supermassive Black Hole Mass - Pitch Angle
  Relation

abstract:
  We present new and stronger evidence for a previously reported relationship
between galactic spiral arm pitch angle P (a measure of the tightness of spiral
structure) and the mass M_BH of a disk galaxy's nuclear supermassive black hole
(SMBH). We use an improved method to accurately measure the spiral arm pitch
angle in disk galaxies to generate quantitative data on this morphological
feature for 34 galaxies with directly measured black hole masses. We find a
relation of log(M/M_sun) = (8.21 +/- 0.16) - (0.062 +/- 0.009)P. This method is
compared with other means of estimating black hole mass to determine its
effectiveness and usefulness relative to other existing relations. We argue
that such a relationship is predicted by leading theories of spiral structure
in disk galaxies, including the density wave theory. We propose this
relationship as a tool for estimating SMBH masses in disk galaxies. This tool
is potentially superior when compared to other methods for this class of galaxy
and has the advantage of being unambiguously measurable from imaging data
alone.


title:
Deconfined Quantum Criticality and Conformal Phase Transition in
  Two-Dimensional Antiferromagnets

abstract:
  Deconfined quantum criticality of two-dimensional $SU(2)$ quantum
antiferromagnets featuring a transition from an antiferromagnetically ordered
ground state to a so-called valence-bond solid state, is governed by a
non-compact CP$^1$ model with a Maxwell term in 2+1 spacetime dimensions. We
introduce a new perspective on deconfined quantum criticality within a
field-theoretic framework based on an expansion in powers of $\epsilon=4-d$ for
fixed number $N$ of complex matter fields. We show that in the allegedly weak
first-order transition regime, a so-called conformal phase transition leads to
a genuine deconfined quantum critical point. In such a transition, the gap
vanishes when the critical point is approached from above and diverges when it
is approached from below. We also find that the spin stiffness has a universal
jump at the critical point.


title:
Real-time observation of fluctuations at the driven-dissipative Dicke
  phase transition

abstract:
  We experimentally study the influence of dissipation on the driven Dicke
quantum phase transition, realized by coupling external degrees of freedom of a
Bose-Einstein condensate to the light field of a high-finesse optical cavity.
The cavity provides a natural dissipation channel, which gives rise to
vacuum-induced fluctuations and allows us to observe density fluctuations of
the gas in real-time. We monitor the divergence of these fluctuations over two
orders of magnitude while approaching the phase transition and observe a
behavior which significantly deviates from that expected for a closed system. A
correlation analysis of the fluctuations reveals the diverging time scale of
the atomic dynamics and allows us to extract a damping rate for the external
degree of freedom of the atoms. We find good agreement with our theoretical
model including both dissipation via the cavity field and via the atomic field.
Utilizing a dissipation channel to non-destructively gain information about a
quantum many-body system provides a unique path to study the physics of
driven-dissipative systems.


title:
A fundamental relation between the metallicity, gas content, and stellar
  mass of local galaxies

abstract:
  Recent results have suggested that the well known mass-metallicity relation
has a strong dependence on the star formation rate, to the extent that a three
dimensional `fundamental metallicity relation' exists which links the three
parameters with minimal scatter. In this work, we use a sample of 4253 local
galaxies observed in atomic hydrogen from the ALFALFA survey to demonstrate,
for the first time, that a similar fundamental relation (the HI-FMR) also
exists between stellar mass, gas-phase metallicity, and HI mass. This latter
relation is likely more fundamental, driving the relation between metallicity,
SFR and mass. At intermediate masses, the behaviour of the gas fundamental
metallicity relation is very similar to that expressed via the star formation
rate. However, we find that the dependence of metallicity on HI content
persists to the highest stellar masses, in contrast to the `saturation' of
metallicity with SFR. It is interesting to note that the dispersion of the
relation is very low at intermediate stellar masses (9< log(M*/Msun) <11),
suggesting that in this range galaxies evolve smoothy, in an equilibrium
between gas inflow, outflow and star formation. At high and low stellar masses,
the scatter of the relation is significantly higher, suggesting that merging
events and/or stochastic accretion and star formation may drive galaxies
outside the relation. We also assemble a sample of galaxies observed in CO.
However, due to a small sample size, strong selection bias, and the influence
of a metallicity-dependent CO/H2 conversion factor, the data are insufficient
to test any influence of molecular gas on metallicity.


title:
A super-Earth-sized planet orbiting in or near the habitable zone around
  Sun-like star

abstract:
  We present the discovery of a super-earth-sized planet in or near the
habitable zone of a sun-like star. The host is Kepler-69, a 13.7 mag G4V-type
star. We detect two periodic sets of transit signals in the three-year flux
time series of Kepler-69, obtained with the Kepler spacecraft. Using the very
high precision Kepler photometry, and follow-up observations, our confidence
that these signals represent planetary transits is >99.1%. The inner planet,
Kepler-69b, has a radius of 2.24+/-0.4 Rearth and orbits the host star every
13.7 days. The outer planet, Kepler-69c, is a super-Earth-size object with a
radius of 1.7+/-0.3 Rearth and an orbital period of 242.5 days. Assuming an
Earth-like Bond albedo, Kepler-69c has an equilibrium temperature of 299 +/- 19
K, which places the planet close to the habitable zone around the host star.
This is the smallest planet found by Kepler to be orbiting in or near habitable
zone of a Sun-like star and represents an important step on the path to finding
the first true Earth analog.


title: On Silicon Group Elements Ejected by Supernovae Type Ia

abstract:
  There is compelling evidence that the peak brightness of a Type Ia supernova
is affected by the electron fraction Ye at the time of the explosion. The
electron fraction is set by the aboriginal composition of the white dwarf and
the reactions that occur during the pre explosive convective burning. To date,
determining the makeup of the white dwarf progenitor has relied on indirect
proxies, such as the average metallicity of the host stellar population. In
this paper, we present analytical calculations supporting the idea that the
electron fraction of the progenitor systematically influences the
nucleosynthesis of silicon group ejecta in Type Ia supernovae. In particular,
we suggest the abundances generated in quasi nuclear statistical equilibrium
are preserved during the subsequent freezeout. This allows one to potential
recovery of Ye at explosion from the abundances recovered from an observed
spectra. We show that measurement of 28Si, 32S, 40Ca, and 54Fe abundances can
be used to construct Ye in the silicon rich regions of the supernovae. If these
four abundances are determined exactly, they are sufficient to recover Ye to 6
percent. This is because these isotopes dominate the composition of
silicon-rich material and iron rich material in quasi nuclear statistical
equilibrium. Analytical analysis shows that the 28Si abundance is insensitive
to Ye, the 32S abundance has a nearly linear trend with Ye, and the 40Ca
abundance has a nearly quadratic trend with Ye. We verify these trends with
post-processing of 1D models and show that these trends are reflected in model
synthetic spectra.


title: Time-resolved double-slit experiment with entangled photons

abstract:
  The double-slit experiment strikingly demonstrates the wave-particle duality
of quantum objects. In this famous experiment, particles pass one-by-one
through a pair of slits and are detected on a distant screen. A distinct
wave-like pattern emerges after many discrete particle impacts as if each
particle is passing through both slits and interfering with itself. While the
direct event-by-event buildup of this interference pattern has been observed
for massive particles such as electrons, neutrons, atoms and molecules, it has
not yet been measured for massless particles like photons. Here we present a
temporally- and spatially-resolved measurement of the double-slit interference
pattern using single photons. We send single photons through a birefringent
double-slit apparatus and use a linear array of single-photon detectors to
observe the developing interference pattern. The analysis of the buildup allows
us to compare quantum mechanics and the corpuscular model, which aims to
explain the mystery of single-particle interference. Finally, we send one
photon from an entangled pair through our double-slit setup and show the
dependence of the resulting interference pattern on the twin photon's measured
state. Our results provide new insight into the dynamics of the buildup process
in the double-slit experiment, and can be used as a valuable resource in
quantum information applications.


title:
Inherent polarization entanglement generated from a monolithic
  semiconductor chip

abstract:
  Creating miniature chip scale implementations of optical quantum information
protocols is a dream for many in the quantum optics community. This is largely
because of the promise of stability and scalability. Here we present a
monolithically integratable chip architecture upon which is built a photonic
device primitive called a Bragg reflection waveguide (BRW). Implemented in
gallium arsenide, we show that, via the process of spontaneous parametric down
conversion, the BRW is capable of directly producing polarization entangled
photons without additional path difference compensation, spectral filtering or
post-selection. After splitting the twin-photons immediately after they emerge
from the chip, we perform a variety of correlation tests on the photon pairs
and show non-classical behaviour in their polarization. Combined with the BRW's
versatile architecture our results signify the BRW design as a serious
contender on which to build large scale implementations of optical quantum
processing devices.


title:
Atmospheric Dependence of the Stopping Cosmic Ray Muon Rate at Ground
  Level

abstract:
  The rate of low energy (< 150 MeV) cosmic ray muons was measured at ground
level as a function of several atmospheric parameters. Stopped muons were
detected in a plastic scintillator block and correlations were determined using
a linear regression model. A strong anti-correlation between fractional changes
in the ground-level pressure and stopping muon rate of -3.0 +- 0.5 was found,
and also a -4.1 +- 0.5 anti-correlation with the fractional change in
atmospheric height at 10 kPa pressure. A weak positive correlation with the 10
kPa temperature was also found, but it was shown not to be statistically
significant in our data set. The same analysis was applied to the total rate of
all charged cosmic ray particles detected with the same apparatus, and good
agreement with previous work was seen. The pressure and height correlation
parameters for stopping muons are larger than for the total rate of all charged
particles by factors of about 1.6 and 3.7, respectively.


title: The 2-loop matter power spectrum and the IR-safe integrand

abstract:
  Large scale structure surveys are likely the next leading probe of
cosmological information. It is therefore crucial to reliably predict their
observables. The Effective Field Theory of Large Scale Structures (EFTofLSS)
provides a manifestly convergent perturbation theory for the weakly non-linear
regime, where dark matter correlation functions are computed in an expansion of
the wavenumber k over the wavenumber associated to the non-linear scale knl. To
push the predictions to higher wavenumbers, it is necessary to compute the
2-loop matter power spectrum. For equal-time correlators, exactly as with
standard perturturbation theory, there are IR divergences present in each
diagram that cancel completely in the final result. We develop a method by
which all 2-loop diagrams are computed as one integral, with an integrand that
is manifestly free of any IR divergences. This allows us to compute the 2-loop
power spectra in a reliable way that is much less numerically challenging than
standard techniques. We apply our method to scaling universes where the linear
power spectrum is a single power law of k, and where IR divergences can
particularly easily interfere with accurate evaluation of loop corrections if
not handled carefully. We show that our results are independent of IR cutoff
and, after renormalization, of the UV cutoff, and comment how the method
presented here naturally generalizes to higher loops.


title:
On the size and location of the X-ray emitting coronae around black
  holes

abstract:
  The observation of energetic X-ray emission from black holes, inconsistent
with thermal emission from an accretion disk, has long indicated the presence
of a "corona" around these objects. However, our knowledge of the geometry,
composition, and processes within black hole coronae is severely lacking. Basic
questions regarding their size and location are still a topic of debate. In
this letter, we show that for black holes with luminosities
$L\gtrsim10^{-2}L_{Edd}$ -- characteristic of many Seyferts, quasars, and
stellar-mass black holes (in their brighter states) -- advanced imaging and
timing data strongly favor X-ray emitting regions that are highly compact, and
only a few Gravitational radii above the accretion disk. The inclusion of a
large number of possible systematics uncertainties does not significantly
change this conclusion with our results still suggesting emission from within
$\sim20$\rg\ in all cases. This result favors coronal models wherein most of
the hard X-ray emission derives from magnetic reconnection in the innermost
disk and/or from processes in the compact base of a central, relativistic jet.


title: On the Approximation of Submodular Functions

abstract:
  Submodular functions are a fundamental object of study in combinatorial
optimization, economics, machine learning, etc. and exhibit a rich
combinatorial structure. Many subclasses of submodular functions have also been
well studied and these subclasses widely vary in their complexity. Our
motivation is to understand the relative complexity of these classes of
functions. Towards this, we consider the question of how well can one class of
submodular functions be approximated by another (simpler) class of submodular
functions. Such approximations naturally allow algorithms designed for the
simpler class to be applied to the bigger class of functions. We prove both
upper and lower bounds on such approximations.
  Our main results are:
  1. General submodular functions can be approximated by cut functions of
directed graphs to a factor of $n^2/4$, which is tight.
  2. General symmetric submodular functions$^{1}$ can be approximated by cut
functions of undirected graphs to a factor of $n-1$, which is tight up to a
constant.
  3. Budgeted additive functions can be approximated by coverage functions to a
factor of $e/(e-1)$, which is tight.
  Here $n$ is the size of the ground set on which the submodular function is
defined.
  We also observe that prior works imply that monotone submodular functions can
be approximated by coverage functions with a factor between $O(\sqrt{n} \log
n)$ and $\Omega(n^{1/3} /\log^2 n) $.


title: Gauge theories in anti-selfdual variables

abstract:
  Some years ago the Nicolai map, viewed as a change of variables from the
gauge connection in a fixed gauge to the anti-selfdual part of the curvature,
has been extended by the first named author to pure YM from its original
definition in N=1 SUSY YM. We study here the perturbative 1PI effective action
in the anti-selfdual variables of any gauge theory, in particular pure YM, QCD
and N=1 SUSY YM. We prove that the one-loop 1PI effective action of a gauge
theory mapped to the anti-selfdual variables in any gauge is identical to the
one of the original theory. This is due to the conspiracy between the Jacobian
of the change to the anti-selfdual variables and an extra functional
determinant that arises from the non-linearity of the coupling of the
anti-selfdual curvature to an external source in the Legendre transform that
defines the 1PI effective action. Hence we establish the one-loop perturbative
equivalence of the mapped and original theories on the basis of the identity of
the one-loop 1PI effective actions. Besides, we argue that the identity of the
perturbative 1PI effective actions extends order by order in perturbation
theory.


title:
Line Profiles of Cores within Clusters: II Signatures of Dynamical
  Collapse during High Mass Star Formation

abstract:
  Observations of atomic or molecular lines can provide important information
about the physical state of star forming regions. In order to investigate the
line profiles from dynamical collapsing massive star forming regions (MSFRs),
we model the emission from hydrodynamic simulations of a collapsing cloud in
the absence of outflows. By performing radiative transfer calculations, we
compute the optically thick HCO+ and optically thin N2H+ line profiles from two
collapsing regions at different epochs. Due to large-scale collapse, the MSFRs
have large velocity gradients, reaching up to 20 km/s/pc across the central
core. The optically thin lines typically contain multiple velocity components
resulting from the superposition of numerous density peaks along the
line-of-sight. The optically thick lines are only marginally shifted to the
blue side of the optically thin line profiles, and frequently do not have a
central depression in their profiles due to self-absorption. As the regions
evolve the lines become brighter and the optically thick lines become broader.
The lower order HCO+ (1-0) transitions are better indicators of collapse than
the higher order (4-3) transitions. We also investigate how the beam sizes
affect profile shapes. Smaller beams lead to brighter and narrower lines that
are more skewed to the blue in HCO+ relative to the true core velocity, but
show multiple components in N2H+. High resolution observations (e.g. with ALMA)
can test these predictions and provide insights into the nature of MSFRs.


title:
Operators on two Banach spaces of continuous functions on locally
  compact spaces of ordinals

abstract:
  Denote by $[0,\omega_1)$ the set of countable ordinals, equipped with the
order topology, let $L_0$ be the disjoint union of the compact ordinal
intervals $[0,\alpha]$ for $\alpha$ countable, and consider the Banach spaces
$C_0[0,\omega_1)$ and $C_0(L_0)$ consisting of all scalar-valued, continuous
functions which are defined on the locally compact Hausdorff spaces
$[0,\omega_1)$ and $L_0$, respectively, and which vanish eventually. Our main
result states that a bounded operator $T$ between any pair of these two Banach
spaces fixes a copy of $C_0(L_0)$ if and only if the identity operator on
$C_0(L_0)$ factors through $T$, if and only if the Szlenk index of $T$ is
uncountable. This implies that the set $\mathscr{S}_{C_0(L_0)}(C_0(L_0))$ of
$C_0(L_0)$-strictly singular operators on $C_0(L_0)$ is the unique maximal
ideal of the Banach algebra $\mathscr{B}(C_0(L_0))$ of all bounded operators on
$C_0(L_0)$, and that $\mathscr{S}_{C_0(L_0)}(C_0[0,\omega_1))$ is the
second-largest proper ideal of $\mathscr{B}(C_0[0,\omega_1))$. Moreover, it
follows that the Banach space $C_0(L_0)$ is primary and complementably
homogeneous.


title: 'Super-Chandrasekhar' Type Ia Supernovae at nebular epochs

abstract:
  We present a first systematic comparison of superluminous Type Ia supernovae
(SNe Ia) at late epochs, including previously unpublished photometric and
spectroscopic observations of SN 2007if, SN 2009dc and SNF20080723-012.
Photometrically, the objects of our sample show a diverse late-time behaviour,
some of them fading quite rapidly after a light-curve break at ~150-200d. The
latter is likely the result of flux redistribution into the infrared, possibly
caused by dust formation, rather than a true bolometric effect. Nebular spectra
of superluminous SNe Ia are characterised by weak or absent [Fe III] emission,
pointing at a low ejecta ionisation state as a result of high densities. To
constrain the ejecta and 56Ni masses of superluminous SNe Ia, we compare the
observed bolometric light curve of SN 2009dc with synthetic model light curves,
focusing on the radioactive tail after ~60d. Models with enough 56Ni to explain
the light-curve peak by radioactive decay, and at the same time sufficient mass
to keep the ejecta velocities low, fail to reproduce the observed light-curve
tail of SN 2009dc because of too much gamma-ray trapping. We instead propose a
model with ~1 solar mass of 56Ni and ~2 solar masses of ejecta, which may be
interpreted as the explosion of a Chandrasekhar-mass white dwarf (WD)
enshrouded by 0.6-0.7 solar masses of C/O-rich material, as it could result
from a merger of two massive C/O WDs. This model reproduces the late light
curve of SN 2009dc well. A flux deficit at peak may be compensated by light
from the interaction of the ejecta with the surrounding material.


title: Renormalization Group Flow of Hexatic Membranes

abstract:
  We investigate hexatic membranes embedded in Euclidean D-dimensional space
using a reparametrization invariant formulation combined with exact
renormalization group (RG) equations. An XY-model coupled to a fluid membrane,
when integrated out, induces long-range interactions between curvatures
described by a Polyakov term in the effective action. We evaluate the
contributions of this term to the running surface tension, bending and Gaussian
rigidities in the approximation of vanishing disclination (vortex) fugacity. We
find a non-Gaussian fixed-point where the membrane is crinkled and has a
non-trivial fractal dimension.


title:
Quarter-BPS AdS5 solutions in M-theory with a T2 bundle over a Riemann
  surface

abstract:
  We study and classify quarter-BPS AdS5 systems in M-theory, whose internal
six-dimensional geometry is a T2 bundle over a Riemann surface and two interval
directions. The general system presented, provides a unified description of all
known AdS5 solutions in M-theory. These systems are governed by two functions,
one that corresponds to the conformal factor of the Riemann surface and another
that describes the T2 fibration. We find solutions that can be organized into
two classes. In the first one, solutions are specified by the conformal factor
of the Riemann surface which satisfies a warped generalization of the
SU(infinity) Toda equation. The system in the second class requires the Riemann
surface to be S2, H2 or T2. Class one contains the M-theory AdS5 solutions of
Lin, Lunin and Maldacena; the solutions of Maldacena and Nunez; the solutions
of Gauntlett, Martelli, Sparks and Waldram; and the eleven-dimensional uplift
of the Y(p,q) metrics. The second includes the recently found solutions of
Beem, Bobev, Wecht and the author. Within each class there are new solutions
that will be studied in a companion paper.


title:
Hausdorff dimension estimates for restricted families of projections in
  $\mathbb{R}^3$

abstract:
  This paper is concerned with restricted families of projections in
$\mathbb{R}^{3}$. Let $K \subset \mathbb{R}^{3}$ be a Borel set with Hausdorff
dimension $\dim K = s > 1$. If $\mathcal{G}$ is a smooth and sufficiently
well-curved one-dimensional family of two-dimensional subspaces, the main
result states that there exists $\sigma(s) > 1$ such that $\dim \pi_{V}(K) \geq
\sigma(s)$ for almost all $V \in \mathcal{G}$. A similar result is obtained for
some specific families of one-dimensional subspaces.


title:
Turbulent amplification of magnetic field driven by dynamo effect at
  rippled shocks

abstract:
  We derive analytically the vorticity generated downstream of a
two-dimensional rippled hydromagnetic shock neglecting fluid viscosity and
resistivity. The growth of the turbulent component of the downstream magnetic
field is driven by the vortical eddies motion. We determine an analytic
time-evolution of the magnetic field amplification at shocks, so far described
only numerically, until saturation occurs due to seed-field reaction to field
lines whirling. The explicit expression of the amplification growth rate and of
the non-linear field back-reaction in terms of the parameters of shock and
interstellar density fluctuations is derived from MHD jump conditions at
rippled shocks. A magnetic field saturation up to the order of milligauss and a
short-time variability in the $X$-ray observations of supernova remnants can be
obtained by using reasonable parameters for the interstellar turbulence.

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


title:
Tidal Tail Ejection as a Signature of Type~Ia Supernovae from White
  Dwarf Mergers

abstract:
  The merger of two white dwarfs may be preceded by the ejection of some mass
in "tidal tails", creating a circumstellar medium around the system. We
consider the variety of observational signatures from this material, which
depend on the lag time between the start of the merger and the ultimate
explosion (assuming one occurs) of the system in a Type Ia supernova. If the
time lag is fairly short, the interaction of the supernova ejecta with the
tails could lead to detectable shock emission at radio, optical, and/or x-ray
wavelengths. At somewhat later times, the tails produce relatively broad NaID
absorption lines with velocity widths of order the white dwarf escape speed
($\sim 1000$ \kms). That none of these signatures have been detected in normal
SNe Ia constrains the lag time to be either very short ($\lesssim 100$ s) or
fairly long ($\gtrsim 100$ yr). If the tails have expanded and cooled over
timescales $\sim 10^4$ yr, they could be observable through narrow NaID and
CaII H&K absorption lines in the spectra, which are seen in some fraction of
SNe Ia. Using a combination of 3D and 1D hydrodynamical codes, we model the
mass-loss from tidal interactions in binary systems, and the subsequent
interactions with the interstellar medium, which produce a slow-moving, dense
shell of gas. We synthesize NaID line profiles by ray-casting through this
shell, and show that in some circumstances tidal tails could be responsible for
narrow absorptions similar to those observed.


title:
A Landau-Ginzburg model for Lagrangian Grassmannians, Langlands duality
  and relations in quantum cohomology

abstract:
  In [Rie08], the second author defined a Landau-Ginzburg model for homogeneous
spaces G/P, as a regular function on an affine subvariety of the Langlands dual
group. In this paper, we reformulate this LG-model (X^,W_t) in the case of the
Lagrangian Grassmannian LG(m) as a rational function on a Langlands dual
orthogonal Grassmannian, in the spirit of work by R. Marsh and the second
author [MR12] for type A Grassmannians. This LG model has some very interesting
features, which are not visible in the type A case, to do with the
non-triviality of Langlands duality.
  We also formulate a conjecture relating our superpotential with the quantum
differential equations of LG(m). Finally, our expression for W_t also leads us
to conjecture new formulas in the quantum Schubert calculus of LG(m).


title: Unconventional magnetism via optical pumping of interacting spin systems

abstract:
  We consider strongly interacting systems of effective spins, subject to
dissipative spin-flip processes associated with optical pumping. We predict the
existence of novel magnetic phases in the steady-state of this system, which
emerge due to the competition between coherent and dissipative processes.
Specifically, for strongly anisotropic spin-spin interactions, we find
ferromagnetic, antiferromagnetic, spin-density-wave, and staggered-XY steady
states, which are separated by nonequilibrium phase transitions meeting at a
Lifshitz point. These transitions are accompanied by quantum correlations,
resulting in spin squeezing. Experimental implementations in ultracold atoms
and trapped ions are discussed.


title:
Multiplicity of solutions for a NLS equations with magnetic fields in
  $\mathbb{R}^{N}$}

abstract:
  We investigate the multiplicity of nontrivial weak solutions for a class of
complex equations. This class of problems are related with the existence of
solitary waves for a nonlinear Sch\"{o}dinger equation. The main result is
established by using minimax methods and Lusternik-Schnirelman theory of
critical points.


title: VLT-CRIRES Survey of Rovibrational CO Emission from Protoplanetary Disks

abstract:
  We present a large, comprehensive survey of rovibrational CO line emission at
4.7 micron from 69 protoplanetary disks, obtained with CRIRES on the ESO Very
Large Telescope at the highest available spectral resolving power (R=95,000,
v=3.2 km/s). The CO fundamental band (Delta v=1) is a well-known tracer of warm
gas in the inner, planet-forming regions of gas-rich disks around young stars,
with the lines formed in the super-heated surfaces of the disks at radii of
0.1-10 AU. Our high spectral resolution data provide new insight into the
kinematics of the inner disk gas. Pure double-peaked Keplerian profiles are
surprisingly uncommon, beyond the frequency expected based on disk inclination.
The majority of the profiles are consistent with emission from a disk plus a
slow (few km/s) molecular disk wind. This is evidenced by analysis of different
categories as well as an overall tendency for line profiles to have excess blue
emission. Weak emission lines from isotopologues and vibrationally excited
levels are readily detected. In general, 13CO lines trace cooler gas than the
bulk 12CO emission and may arise from further out in the disk, as indicated by
narrower line profiles. A high fraction of the sources show vibrationally
excited emission (~50%) which is correlated with accretion luminosity,
consistent with ultra-violet (UV) fluorescent excitation. Disks around
early-type Herbig AeBe stars have narrower lines, on average, than their
lower-mass late-type counterparts, due to their increased luminosity.
Evolutionary changes in CO are also seen. Removal of the protostellar envelope
between class I and II results in the disappearance of the strong absorption
lines and CO ice feature characteristic of class I spectra. However, CO
emission from class I and II objects is similar in detection frequency,
excitation and line shape, indicating that inner disk characteristics are
established early.


title:
Modeling the near-UV band of GK stars, Paper III: Dependence on
  abundance pattern

abstract:
  We extend the grid of NLTE models presented in Paper II to explore variations
in abundance pattern in two ways: 1) The adoption of the Asplund et al. (2009)
(GASS10) abundances, 2) For stars of metallicity, [M/H], of -0.5, the adoption
of a non-solar enhancement of alpha-elements by +0.3 dex. Moreover, our grid of
synthetic spectral energy distributions (SEDs) is interpolated to a finer
numerical resolution in both T_eff (Delta T_eff = 25 K) and log g (Delta log g
= 0.25). We compare the values of T_eff and log g inferred from fitting LTE and
Non-LTE SEDs to observed SEDs throughout the entire visible band, and in an ad
hoc "blue" band. We compare our spectrophotometrically derived T_eff values to
a variety of T_eff calibrations, including more empirical ones, drawn from the
literature. For stars of solar metallicity, we find that the adoption of the
GASS10 abundances lowers the inferred T_eff value by 25 - 50 K for late-type
giants, and NLTE models computed with the GASS10 abundances give T_eff results
that are marginally in better agreement with other T_eff calibrations. For
stars of [M/H]=-0.5 there is marginal evidence that adoption of
alpha-enhancement further lowers the derived T_eff value by 50 K. Stellar
parameters inferred from fitting NLTE models to SEDs are more dependent than
LTE models on the wavelength region being fitted, and we find that the effect
depends on how heavily line blanketed the fitting region is, whether the
fitting region is to the blue of the Wien peak of the star's SED, or both.


title: How important tasks are performed: peer review

abstract:
  The advancement of various fields of science depends on the actions of
individual scientists via the peer review process. The referees' work patterns
and stochastic nature of decision making both relate to the particular features
of refereeing and to the universal aspects of human behavior. Here, we show
that the time a referee takes to write a report on a scientific manuscript
depends on the final verdict. The data is compared to a model, where the review
takes place in an ongoing competition of completing an important composite task
with a large number of concurrent ones - a Deadline -effect. In peer review
human decision making and task completion combine both long-range
predictability and stochastic variation due to a large degree of ever-changing
external "friction".


title:
Newton-Based Optimization for Kullback-Leibler Nonnegative Tensor
  Factorizations

abstract:
  Tensor factorizations with nonnegative constraints have found application in
analyzing data from cyber traffic, social networks, and other areas. We
consider application data best described as being generated by a Poisson
process (e.g., count data), which leads to sparse tensors that can be modeled
by sparse factor matrices. In this paper we investigate efficient techniques
for computing an appropriate canonical polyadic tensor factorization based on
the Kullback-Leibler divergence function. We propose novel subproblem solvers
within the standard alternating block variable approach. Our new methods
exploit structure and reformulate the optimization problem as small independent
subproblems. We employ bound-constrained Newton and quasi-Newton methods. We
compare our algorithms against other codes, demonstrating superior speed for
high accuracy results and the ability to quickly find sparse solutions.


title:
Improvement/Extension of Modular Systems as Combinatorial Reengineering
  (Survey)

abstract:
  The paper describes development (improvement/extension) approaches for
composite (modular) systems (as combinatorial reengineering). The following
system improvement/extension actions are considered: (a) improvement of systems
component(s) (e.g., improvement of a system component, replacement of a system
component); (b) improvement of system component interconnection
(compatibility); (c) joint improvement improvement of system components(s) and
their interconnection; (d) improvement of system structure (replacement of
system part(s), addition of a system part, deletion of a system part,
modification of system structure). The study of system improvement approaches
involve some crucial issues: (i) scales for evaluation of system components and
component compatibility (quantitative scale, ordinal scale, poset-like scale,
scale based on interval multiset estimate), (ii) evaluation of integrated
system quality, (iii) integration methods to obtain the integrated system
quality. The system improvement/extension strategies can be examined as
seleciton/combination of the improvement action(s) above and as modification of
system structure. The strategies are based on combinatorial optimization
problems (e.g., multicriteria selection, knapsack problem, multiple choice
problem, combinatorial synthesis based on morphological clique problem,
assignment/reassignment problem, graph recoloring problem, spanning problems,
hotlink assignment). Here, heuristics are used. Various system
improvement/extension strategies are presented including illustrative numerical
examples.


title:
Myers-Pospelov Model as an Ensemble of Pais-Uhlenbeck Oscillators:
  Unitarity and Lorentz Invariance Violation

abstract:
  We study a generalization of a Pais-Uhlenbeck oscillator for fermionic
variables. Next, we consider an ensemble of these oscillators and we identify a
particular case of the Myers-Pospelov model which is relevant for effective
theories of quantum gravity. Finally, by taking the advantage of this
connection, we analyze, for this model, the unitarity at one loop order in the
low energy regime where no ghost states can be created on-shell. This energy
regime is the relevant one when we consider the Myers-Pospelov model as a true
effective theory coming from new space-time structure.


title: An Emerging Coherent Picture of Red Supergiant Supernova Explosions

abstract:
  Three lines of evidence indicate that in the most common type of core
collapse supernovae, the energy deposited in the ejecta by the exploding core
is approximately proportional to the progenitor mass cubed. This results stems
from an observed uniformity of light curve plateau duration, a correlation
between mass and ejecta velocity, and the known correlation between luminosity
and velocity. This result ties in analytical and numerical models together with
observations, providing us with clues as to the mechanism via which the
explosion of the core deposits a small fraction of its energy into the hurled
envelope.


title:
Viscosity control of the dynamic self-assembly in ferromagnetic
  suspensions

abstract:
  Recent studies of dynamic self-assembly in ferromagnetic colloids suspended
in liquid-air or liquid-liquid interfaces revealed a rich variety of dynamic
structures ranging from linear snakes to axisymmetric asters, which exhibit
novel morphology of the magnetic ordering accompanied by large-scale
hydrodynamic flows. Based on controlled experiments and first principle theory,
we argue that the transition from snakes to asters is governed by the viscosity
of the suspending liquid where less viscous liquids favor snakes and more
viscous, asters. By obtaining analytic solutions of the time-averaged
Navier-Stokes equations, we gain insights into the role of mean hydrodynamic
flows and an overall balance of forces governing the self-assembly. Our results
illustrate that the viscosity can be used to control the outcome of the dynamic
self-assembly in magnetic colloidal suspensions.


title: Adiabatic quantum motors

abstract:
  When parameters are varied periodically, charge can be pumped through a
mesoscopic conductor without applied bias. Here, we consider the inverse effect
in which a transport current drives a periodic variation of an adiabatic degree
of freedom. This provides a general operating principle for adiabatic quantum
motors, for which we develop a comprehensive theory. We relate the work
performed per cycle on the motor degree of freedom to characteristics of the
underlying quantum pump and discuss the motor's efficiency. Quantum motors
based on chaotic quantum dots operate solely due to quantum interference,
motors based on Thouless pumps have ideal efficiency.


title: B decays into radially excited charmed mesons

abstract:
  It has been recently argued that some longstanding problems in semileptonic B
decays can be solved provided the branching ratio for the $B\to
D^{\prime(\ast)}$ semileptonic decays are large enough. We have studied these
decays in a constituent quark model which has been successful in describing
semileptonic and non-leptonic B decays into orbitally excited charmed mesons.
Our results do not confirm the hypothesis of large branching ratios for the
$B\to D^{\prime(\ast)}$ semileptonic decays. In addition, we calculate the
non-leptonic $B\to D'\pi$ decays which can provide an independent test of the
form factors involved in the $B\to D^{\prime(\ast)}$ reactions.


title:
An oscillating motion of a red blood cell and a neutrally buoyant
  particle in Poiseuille flow in a narrow channel

abstract:
  Two motions of oscillation and vacillating breathing (swing) of a red blood
cell have been observed in bounded Poiseuille flows (Phys. Rev. E 85, 16307
(2012)). To understand such motions, we have studied the oscillating motion of
a neutrally buoyant rigid particle of the same shape in Poiseuille flow in a
narrow channel and obtained that the crucial point is to have the particle
interacting with Poiseuille flow with its mass center moving up and down in the
channel central region. Since the mass center of the cell migrates toward the
channel central region, its oscillating motion of the inclination angle is
similar to the aforementioned motion as long as the cell keeps the shape of
long body. But as the up-and-down oscillation of the cell mass center damps
out, the oscillating motion of the inclination angle also damps out and the
cell inclination angle approaches to a fixed angle.


title:
Emulating Solid-State Physics with a Hybrid System of Ultracold Ions and
  Atoms

abstract:
  We propose and theoretically investigate a hybrid system composed of a
crystal of trapped ions coupled to a cloud of ultracold fermions. The ions form
a periodic lattice and induce a band structure in the atoms. This system
combines the advantages of scalability and tunability of ultracold atomic
systems with the high fidelity operations and detection offered by trapped ion
systems. It also features close analogies to natural solid-state systems, as
the atomic degrees of freedom couple to phonons of the ion lattice, thereby
emulating a solid-state system. Starting from the microscopic many-body
Hamiltonian, we derive the low energy Hamiltonian including the atomic band
structure and give an expression for the atom-phonon coupling. We discuss
possible experimental implementations such as a Peierls-like transition into a
period-doubled dimerized state.


title: BKL maps and Poincar\'e sections

abstract:
  Cosmological billiards arise as a map of the solution to the Einstein
equations, when the most general symmetry of the metric tensor is implemented,
under the BKL (named after Belinskii, Khalatnikov and Lifshitz) paradigm, for
which points are spatially decoupled in the asymptotical limit close to the
cosmological singularity. Cosmological billiards in $4=3+1$ dimensions for the
case of pure gravity are analyzed for those features, for which the content of
Weyl reflections in the BKL maps requires definition of a 3-dimensional
restricted phase space. The role of Poincar\'e sections in these processes is
outlined. The quantum regime is investigated within this framework: as a
result, 1-epoch BKL eras are found to be the most probable configuration at
which the wavefunctions have to be evaluated; furthermore, BKL eras containing
$n>>1$ epochs are shown to be a less probable configuration for the
wavefunctions. This description of the dynamics allows one to gain information
about the connections between the statistical characterization of the maps
which imply the different symmetry-quotienting mechanisms and the
characterization of the semiclassical limit of the wavefunctions for the
classical trajectories, for which the phenomenon of 'scars' on the wavefunction
is found for other kinds of billiards.


title: Fast exact digital differential analyzer for circle generation

abstract:
  In the first part of the paper we present a short review of applications of
digital differential analyzers (DDA) to generation of circles showing that they
can be treated as one-step numerical schemes. In the second part we present and
discuss a novel fast algorithm based on a two-step numerical scheme (explicit
midpoint rule). Although our algorithm is as cheap as the simplest one-step DDA
algoritm (and can be represented in terms of shifts and additions), it
generates circles with maximal accuracy, i.e., it is exact up to round-off
errors.


title: Coupling a small torsional oscillator to large optical angular momentum

abstract:
  We propose a new configuration for realizing torsional optomechanics: an
optically trapped windmill-shaped dielectric interacting with Laguerre-Gaussian
cavity modes containing both angular and radial nodes. In contrast to existing
schemes, our method can couple mechanical oscillators smaller than the optical
beam waist to the in-principle unlimited orbital angular momentum that can be
carried by a single photon, and thus generate substantial optomechanical
interactions. Combining the advantages of small mass, large coupling, and low
clamping losses, our work conceptually opens the way for the observation of
quantum effects in torsional optomechanics.


title: An Optimization-Based Atomistic-to-Continuum Coupling Method

abstract:
  We present a new optimization-based method for atomistic-to-continuum (AtC)
coupling. The main idea is to cast the coupling of the atomistic and continuum
models as a constrained optimization problem with virtual Dirichlet controls on
the interfaces between the atomistic and continuum subdomains. The optimization
objective is to minimize the error between the atomistic and continuum
solutions on the overlap between the two subdomains, while the atomistic and
continuum force balance equations provide the constraints. Splitting of the
atomistic and continuum problems instead of blending them and their subsequent
use as constraints in the optimization problem distinguishes our approach from
the existing AtC formulations. We present and analyze the method in the context
of a one-dimensional chain of atoms modeled using a linearized two-body
next-nearest neighbor interactions.


title: Thermodynamic Approach to Generalized Continua

abstract:
  Governing equations of dissipative generalized solid mechanics are derived by
thermodynamic methods in the Piola-Kirchhoff framework using the Liu procedure.
The isotropic small strain case is investigated in more detail. The connection
to the Ginzburg-Landau type evolution, dual internal variables, and a
thermodynamic generalization of the standard linear solid model of rheology is
demonstrated. Specific examples are chosen to emphasize experimental
confirmations and predictions beyond less general approaches.


title:
Towards a Population Synthesis Model of Objects formed by
  Self-Gravitating Disc Fragmentation and Tidal Downsizing

abstract:
  Recently, the gravitational instability (GI) model of giant planet and brown
dwarf formation has been revisited and recast into what is often referred to as
the "tidal downsizing" hypothesis. The fragmentation of self-gravitating
protostellar discs into gravitationally bound embryos - with masses of a few to
tens of Jupiter masses, at semi major axes above 30 - 40 au - is followed by
grain sedimentation inside the embryo, radial migration towards the central
star and tidal disruption of the embryo's upper layers. The properties of the
resultant object depends sensitively on the timescales upon which each process
occurs. Therefore, GI followed by tidal downsizing can theoretically produce
objects spanning a large mass range, from terrestrial planets to giant planets
and brown dwarfs. Whether such objects can be formed in practice, and what
proportions of the observed population they would represent, requires a more
involved statistical analysis.
  We present a simple population synthesis model of star and planet formation
via GI and tidal downsizing. We couple a semi-analytic model of protostellar
disc evolution to analytic calculations of fragmentation, initial embryo mass,
grain growth and sedimentation, embryo migration and tidal disruption. While
there are key pieces of physics yet to be incorporated, it represents a first
step towards a mature statistical model of GI and tidal downsizing as a mode of
star and planet formation.
  We show results from four runs of the population synthesis model, varying the
opacity law and the strength of migration, as well as investigating the effect
of disc truncation during the fragmentation process. Our early results suggest
that GI plus tidal downsizing is not the principal mode of planet formation,
but remains an excellent means of forming gas giant planets, brown dwarfs and
low mass stars at large semimajor axes. (Abridged)


title: Small World Picture of Worldwide Seismic Events

abstract:
  The understanding of long-distance relations between seismic activities has
for long been of interest to seismologists and geologists. In this paper we
have used data from the world-wide earthquake catalog for the period between
1972 and 2011 to generate a network of sites around the world for earthquakes
with magnitude m $\geq$ 4.5 in the Richter scale. After the network
construction, we have analyzed the results under two viewpoints. Firstly, in
contrast to previous works, which have considered just small areas, we showed
that the best fitting for networks of seismic events is not a pure power law,
but a power law with exponential cutoff; we also have found that the global
network presents small-world properties. Secondly, we have found that the time
intervals between successive earthquakes have a cumulative probability
distribution well fitted by nontraditional functional forms. The implications
of our results are significant because they seem to indicate that seisms around
the world are not independent. In this paper we provide evidence to support
this argument.


title: Universal spin dynamics in two-dimensional Fermi gases

abstract:
  Harnessing spins as carriers for information has emerged as an elegant
extension to the transport of electrical charges. The coherence of such spin
transport in spintronic circuits is determined by the lifetime of spin
excitations and by spin diffusion. Fermionic quantum gases are a unique system
to study the fundamentals of spin transport from first principles since
interactions can be precisely tailored and the dynamics is on time scales which
are directly observable. In particular at unitarity, spin transport is dictated
by diffusion and is expected to reach a universal, quantum-limited diffusivity
on the order of hbar/m. Here, we study the non-equilibrium dynamics of a
two-dimensional Fermi gas following a quench into a metastable, transversely
polarized spin state. Using the spin-echo technique, we measure the yet lowest
transverse spin diffusion constant of 0.25(3) hbar/m. For weak interactions, we
observe a coherent collective transverse spin-wave mode that exhibits mode
softening when approaching the hydrodynamic regime.


title:
Might quantum-induced deviations from the Einstein equations detectably
  affect gravitational wave propagation?

abstract:
  A quantum measurement-like event can produce any of a number of
macroscopically distinct results, with corresponding macroscopically distinct
gravitational fields, from the same initial state. Hence the probabilistically
evolving large-scale structure of space-time is not precisely or even always
approximately described by the deterministic Einstein equations. Since the
standard treatment of gravitational wave propagation assumes the validity of
the Einstein equations, it is questionable whether we should expect all its
predictions to be empirically verified. In particular, one might expect the
stochasticity of amplified quantum indeterminacy to cause coherent
gravitational wave signals to decay faster than standard predictions suggest.
This need not imply that the radiated energy flux from gravitational wave
sources differs from standard theoretical predictions. An underappreciated
bonus of gravitational wave astronomy is that either detecting or failing to
detect predicted gravitational wave signals would constrain the form of the
semi-classical theory of gravity that we presently lack.


title:
Emerging spectra of singular correlation matrices under small power-map
  deformations

abstract:
  Correlation matrices are a standard tool in the analysis of the time
evolution of complex systems in general and financial markets in particular.
Yet most analysis assume stationarity of the underlying time series. This tends
to be an assumption of varying and often dubious validity. The validity of the
assumption improves as shorter time series are used. If many time series are
used this implies an analysis of highly singular correlation matrices. We
attack this problem by using the so called {\it power map} which was introduced
to reduce noise. Its non-linearity breaks the degeneracy of the zero
eigenvalues and we analyze the sensitivity of the so emerging spectra to
correlations. This sensitivity will be demonstrated for uncorrelated and
correlated Wishart ensembles.


title: Semiparametric Sparse Discriminant Analysis

abstract:
  In recent years, a considerable amount of work has been devoted to
generalizing linear discriminant analysis to overcome its incompetence for
high-dimensional classification (Witten & Tibshirani 2011, Cai & Liu 2011, Mai
et al. 2012, Fan et al. 2012). In this paper, we develop high-dimensional
semiparametric sparse discriminant analysis (HD-SeSDA) that generalizes the
normal-theory discriminant analysis in two ways: it relaxes the Gaussian
assumptions and can handle non-polynomial (NP) dimension classification
problems. If the underlying Bayes rule is sparse, HD-SeSDA can estimate the
Bayes rule and select the true features simultaneously with overwhelming
probability, as long as the logarithm of dimension grows slower than the cube
root of sample size. Simulated and real examples are used to demonstrate the
finite sample performance of HD-SeSDA. At the core of the theory is a new
exponential concentration bound for semiparametric Gaussian copulas, which is
of independent interest.


title:
Searching for gravitational waves with the LIGO and Virgo
  interferometers

abstract:
  The first generation of ground-based interferometric gravitational wave
detectors, LIGO, GEO and Virgo, have operated and taken data at their design
sensitivities over the last few years. The data has been examined for the
presence of gravitational wave signals. Presented here is a comprehensive
review of the most significant results. The network of detectors is currently
being upgraded and extended, providing a large likelihood for observations.
These future prospects will also be discussed.


title: Non Total-Unimodularity Neutralized Simplicial Complexes

abstract:
  Given a simplicial complex K with weights on its simplices and a chain on it,
the Optimal Homologous Chain Problem (OHCP) is to find a chain with minimal
weight that is homologous (over the integers) to the given chain. The OHCP is
NP-complete, but if the boundary matrix of K is totally unimodular (TU), it
becomes solvable in polynomial time when modeled as a linear program (LP). We
define a condition on the simplicial complex called non total-unimodularity
neutralized, or NTU neutralized, which ensures that even when the boundary
matrix is not TU, the OHCP LP must contain an integral optimal vertex for every
input chain. This condition is a property of K, and is independent of the input
chain and the weights on the simplices. This condition is strictly weaker than
the boundary matrix being TU. More interestingly, the polytope of the OHCP LP
may not be integral under this condition. Still, an integral optimal vertex
exists for every right-hand side, i.e., for every input chain. Hence a much
larger class of OHCP instances can be solved in polynomial time than previously
considered possible. As a special case, we show that 2-complexes with trivial
first homology group are guaranteed to be NTU neutralized.


title:
Complexity and polymorphisms for digraph constraint problems under some
  basic constructions

abstract:
  The role of polymorphisms in determining the complexity of constraint
satisfaction problems is well established.
  In this context we study the stability of CSP complexity and polymorphism
properties under some basic graph theoretic constructions. As applications we
observe a collapse in the applicability of algorithms for CSPs over directed
graphs with both a total source and a total sink: the corresponding CSP is
solvable by the "few subpowers algorithm" if and only if it is solvable by a
local consistency check algorithm. Moreover, we find that the property of
"strict width" and solvability by few subpowers are unstable under first order
reductions. The analysis also yields a complete characterisation of the main
polymorphism properties for digraphs whose symmetric closure is a complete
graph.


title:
Wide-field wide-band interferometric imaging:The WB A-Projection and
  hybrid algorithms

abstract:
  Variations of the antenna primary beam (PB) pattern as a function of time,
frequency and polarization form one of the dominant direction-dependent effects
at most radio frequency bands. These gains may also vary from antenna to
antenna. The A-Projection algorithm, published earlier, accounts for the
effects of the narrow-band antenna PB in full polarization. In this paper we
present the Wide-Band A-Projection algorithm (WB A-Projection) to include the
effects of wide bandwidth in the A-term itself and show that the resulting
algorithm simultaneously corrects for the time, frequency and polarization
dependence of the PB. We discuss the combination of the WB A-Projection and the
Multi-term Multi Frequency Synthesis (MT-MFS) algorithm for simultaneous
mapping of the sky brightness distribution and the spectral index distribution
across a wide field of view. We also discuss the use of the narrow-band
A-Projection algorithm in hybrid imaging schemes that account for the frequency
dependence of the PB in the image domain.


title:
Thermally-induced Phases in an Ising Kondo Lattice Model on a Triangular
  Lattice: Partial Disorder and Kosterlitz-Thouless State

abstract:
  Magnetic and electronic properties of a Kondo lattice model with Ising
localized spins are studied on an isotropic triangular lattice. By using Monte
Carlo simulation, we present that the model shows a rich phase diagram with
four dominant states: two-sublattice stripe, three-sublattice ferrimganetic,
partially disordered, and Kosterlitz-Thouless like quasi-long-range ordered
states. Among them, the partially disordered state and Kosterlitz-Thouless like
state are intermediate phases induced by thermal fluctuations in the phase
competing regime; they are present only at finite temperatures and eventually
taken over by another phases as the temperature is further lowered. Although
the Kosterlitz-Thouless like state was found also in triangular Ising
antiferromagnets with further-neighbor interactions, the partially disordered
state has not been reported in the localized spin only models in two
dimensions. Interestingly, the partially disordered phase is also peculiar in
the charge degree of freedom of itinerant electrons; it is insulating and
accompanied by charge disproportionation. From a combined analysis of a
mean-field calculation of the band structure and Monte Carlo simulation, we
conclude that the partial disorder in the present model is stabilized by the
Slater mechanism.


title:
Wide-span and tunable-wavelength photon pairs around 1.55 \mu m from a
  silicon nanophotonic chip

abstract:
  Using a compact optically-pumped silicon nanophotonic chip consisting of
coupled silicon microrings, we generate photon pairs in multiple pairs of
wavelengths around 1.55 \mu m. The wavelengths are tunable over several
nanometers, demonstrating the capability to generate wavelength division
multiplexed photon pairs at freely-chosen telecommunications-band wavelengths.


title: Conditional Random Quantities and Compounds of Conditionals

abstract:
  In this paper we consider finite conditional random quantities and
conditional previsions assessments in the setting of coherence. We use a
suitable representation for conditional random quantities; in particular the
indicator of a conditional event $E|H$ is looked at as a three-valued quantity
with values 1, or 0, or $p$, where $p$ is the probability of $E|H$. We
introduce a notion of iterated conditional random quantity of the form
$(X|H)|K$ defined as a suitable conditional random quantity, which coincides
with $X|HK$ when $H \subseteq K$. Based on a recent paper by S. Kaufmann, we
introduce a notion of conjunction of two conditional events and then we analyze
it in the setting of coherence. We give a representation of the conjoined
conditional and we show that this new object is a conditional random quantity.
We examine some cases of logical dependencies, by also showing that the
conjunction may be a conditional event; moreover, we introduce the negation of
the conjunction and by De Morgan's Law the operation of disjunction. Finally,
we give the lower and upper bounds for the conjunction and the disjunction of
two conditional events, by showing that the usual probabilistic properties
continue to hold.


title:
New Limits on 21cm EoR From PAPER-32 Consistent with an X-Ray Heated IGM
  at z=7.7

abstract:
  We present new constraints on the 21cm Epoch of Reionization (EoR) power
spectrum derived from 3 months of observing with a 32-antenna,
dual-polarization deployment of the Donald C. Backer Precision Array for
Probing the Epoch of Reionization (PAPER) in South Africa. In this paper, we
demonstrate the efficacy of the delay-spectrum approach to avoiding
foregrounds, achieving over 8 orders of magnitude of foreground suppression (in
$\textrm{mK}^2$). Combining this approach with a procedure for removing
off-diagonal covariances arising from instrumental systematics, we achieve a
best 2-sigma upper limit of $(41\,\textrm{mK})^2$ for $k=0.27
h\textrm{Mpc}^{-1}$ at $z=7.7$. This limit falls within an order of magnitude
of the brighter predictions of the expected 21cm EoR signal level. Using the
upper limits set by these measurements, we generate new constraints on the
brightness temperature of 21cm emission in neutral regions for various
reionization models. We show that for several ionization scenarios, our
measurements are inconsistent with cold reionization. That is, heating of the
neutral intergalactic medium (IGM) is necessary to remain consistent with the
constraints we report. Hence, we have suggestive evidence that by $z=7.7$, the
HI has been warmed from its cold primordial state, probably by X-rays from
high-mass X-ray binaries or mini-quasars. The strength of this evidence depends
on the ionization state of the IGM, which we are not yet able to constrain.
This result is consistent with standard predictions for how reionization might
have proceeded.


title:
Toward understanding the anisotropic point spread function of
  Suprime-Cam and its impact on cosmic shear measurement

abstract:
  We examined the anisotropic point spread function (PSF) of Suprime-Cam data
utilizing dense star field data. We decomposed the PSF ellipticities into three
components, the optical aberration, atmospheric turbulence, and
chip-misalignment in an empirical manner, and evaluated the amplitude of each
component. We found that, for long-exposure data, the optical aberration has
the largest contribution to the PSF ellipticities, which could be modeled well
by a simple analytic function based on the lowest-order aberration theory. The
statistical properties of PSF ellipticities resulting from the atmospheric
turbulence were investigated by using the numerical simulations. The simulation
results are in a reasonable agreement with the observed data. It is also found
that the optical PSF can be well corrected by the standard correction method
with a polynomial fitting function. However, for the atmospheric PSF, its
correction is affected by the common limitation caused by sparse sampling of
PSFs due to a limited number of stars. We also examined the effects of the
residual PSF anisotropies on Suprime-Cam cosmic shear data. We found that the
shape and amplitude of the B-mode shear variance are broadly consistent with
those of the residual PSF ellipticities measured from the dense star field
data. This indicates that most of the sources of residual systematic are
understood, which is an important step for cosmic shear statistics to be a
practical tool of the precision cosmology.


title:
Signatures of shear thinning-thickening transition in dense athermal
  shear flows

abstract:
  In non-equilibrium molecular dynamics simulations of dense athermal shear
flows, we observe the transition from shear thinning to shear thickening at a
crossover shear rate $\dot\gamma_c$. Shear thickening occurs when $\frac{{\rm d
(ln} T_g)}{{\rm d (ln}\dot\gamma)}>2$ with $T_g$ the granular temperature. At
the transition, the pair distribution function shows the strongest anisotropy.
Meanwhile, the dynamics undergo apparent changes, signified by distinct scaling
behaviors of the mean squared displacement and relaxation time on both sides of
$\dot\gamma_c$. These features serve as robust signatures of the shear
thinning-thickening transition.


title: Polygon Matching and Indexing Under Affine Transformations

abstract:
  Given a collection $\{Z_1,Z_2,\ldots,Z_m\}$ of $n$-sided polygons in the
plane and a query polygon $W$ we give algorithms to find all $Z_\ell$ such that
$W=f(Z_\ell)$ with $f$ an unknown similarity transformation in time independent
of the size of the collection. If $f$ is a known affine transformation, we show
how to find all $Z_\ell$ such that $W=f(Z_\ell)$ in $O(n+\log(m))$ time.
  For a pair $W,W^\prime$ of polygons we can find all the pairs
$Z_\ell,Z_{\ell^\prime}$ such that $W=f(Z_\ell)$ and
$W^\prime=f(Z_{\ell^\prime})$ for an unknown affine transformation $f$ in
$O(m+n)$ time.
  For the case of triangles we also give bounds for the problem of matching
triangles with variable vertices, which is equivalent to affine matching
triangles in noisy conditions.


title: Schr\"odinger group and quantum finance

abstract:
  Using the one dimensional free particle symmetries, the quantum finance
symmetries are obtained. Namely, it is shown that Black-Scholes equation is
invariant under Schr\"odinger group. In order to do this, the one dimensional
free non-relativistic particle and its symmetries are revisited. To get the
Black-Scholes equation symmetries, the particle mass is identified as the
inverse of square of the volatility. Furthermore, using financial variables, a
Schr\"odinger algebra representation is constructed.


title:
Constraints on free-free emission from Anomalous Microwave Emission
  Sources in the Perseus Molecular Cloud

abstract:
  We present observations performed with the Green Bank Telescope at 1.4 and 5
GHz of three strips coincident with the anomalous microwave emission features
previously identified in the Perseus molecular cloud at 33 GHz with the Very
Small Array. With these observations we determine the level of the low
frequency (~1 - 5 GHz) emission. We do not detect any significant extended
emission in these regions and we compute conservative 3\sigma upper limits on
the fraction of free-free emission at 33 GHz of 27%, 12%, and 18% for the three
strips, indicating that the level of the emission at 1.4 and 5 GHz cannot
account for the emission observed at 33 GHz. Additionally, we find that the low
frequency emission is not spatially correlated with the emission observed at 33
GHz. These results indicate that the emission observed in the Perseus molecular
cloud at 33 GHz, is indeed in excess over the low frequency emission, hence
confirming its anomalous nature.


title:
Intrinsicness of the Newton polygon for smooth curves on
  $\mathbb{P}^1\times \mathbb{P}^1$

abstract:
  Let $C$ be a smooth projective curve in $\mathbb{P}^1\times \mathbb{P}^1$ of
genus $g\neq 4$, and assume that it is birationally equivalent to a curve
defined by a Laurent polynomial that is non-degenerate with respect to its
Newton polygon $\Delta$. Then we show that the convex hull $\Delta^{(1)}$ of
the interior lattice points of $\Delta$ is a standard rectangle, up to a
unimodular transformation. Our main auxiliary result, which we believe to be
interesting in its own right, is that the first scrollar Betti numbers of
$\Delta$-non-degenerate curves are encoded in the combinatorics of
$\Delta^{(1)}$, if $\Delta$ satisfies some mild conditions.


title:
Complete Decompositions of Coxeter groups orbit products of $A_2, C_2,
  G_2$ and $H_2$ and some limits for them

abstract:
  Orbits of the Weyl reflection groups attached to the simple Lie groups $A_2,
C_2, G_2$ and Coxeter group $H_2$ are considered. For each of the groups
products of any two orbits are decomposed into the union of the orbits. Results
are presented in a single formula for each of the groups. Orbits are considered
as functions of two variables and limits for such functions are mentioned.


title:
A measurement of the energy and timing resolution of GlueX Forward
  Calorimeter using an electron beam

abstract:
  The performance of the GlueX Forward Calorimeter was studied using a small
version of the detector and a variable energy electron beam derived from the
Hall B tagger at Jefferson Lab. For electron energies from 110 MeV to 260 MeV,
which are near the lower-limits of the design sensitivity, the fractional
energy resolution was measured to range from 20% to 14%, which meets the design
goals. The use of custom 250 MHz flash ADCs for readout allowed precise
measurements of signal arrival times. The detector achieved timing resolutions
of 0.38 ns for a single 100 mV pulse, which will allow timing discrimination of
photon beam bunches and out-of-time background during the operation of the
GlueX detector.


title:
Magnetostructural transition, metamagnetism, and magnetic phase
  coexistence in Co10Ge3O16

abstract:
  Co10Ge3O16 crystallizes in an intergrowth structure featuring alternating
layers of spinel and rock salt. Variable-temperature powder synchrotron X-ray
and neutron diffraction, magnetometry, and heat capacity experiments reveal a
magnetostructural transition at T_N = 203 K. This rhombohedral-to-monoclinic
transition involves a slight elongation of the CoO6 octahedra along the apical
axis. Below T_N, the application of a large magnetic field causes a
reorientation of the Co^2+ Ising spins. This metamagnetic transition is
first-order as evidenced by a latent heat observed in temperature-dependent
measurements. This transition is initially seen at T = 180 K as a broad upturn
in the M-H near H_C = 3.9 T. The upturn sharpens into a kink at T = 120 K and a
"butterfly" shape emerges, with the transition causing hysteresis at high
fields while linear and reversible behavior persists at low fields. H_C
decreases as temperature is lowered and the loops at positive and negative
fields merge beneath T = 20 K. The antiferromagnetism is described by k_M = (00
1/2) and below T = 20 K a small uncompensated component with k_M = (000)
spontaneously emerges. Despite the Curie-Weiss analysis and ionic radius
indicating the Co2+ is in its high-spin state, the low-temperature M-H trends
toward saturation at M_S = 1.0 uB/Co. We conclude that the field-induced state
is a ferrimagnet, rather than a S = 1/2 ferromagnet. The unusual H-T phase
diagram is discussed with reference to other metamagnets and Co(II) systems.


title: Concentration inequalities via zero bias couplings

abstract:
  The tails of the distribution of a mean zero, variance $\sigma^2$ random
variable $Y$ satisfy concentration of measure inequalities of the form
$\mathbb{P}(Y \ge t) \le \exp(-B(t))$ for $$ B(t)=\frac{t^2}{2( \sigma^2 + ct)}
\quad \mbox{for $t \ge 0$, and} \quad B(t)=\frac{t}{c}\left( \log t - \log \log
t - \frac{\sigma^2}{c}\right) \quad \mbox{for $t>e$} $$ whenever there exists a
zero biased coupling of $Y$ bounded by $c$, under suitable conditions on the
existence of the moment generating function of $Y$. These inequalities apply in
cases where $Y$ is not a function of independent variables, such as for the
Hoeffding statistic $Y=\sum_{i=1}^n a_{i\pi(i)}$ where $A=(a_{ij})_{1 \le i,j
\le n} \in \mathbb{R}^{n \times n}$ and the permutation $\pi$ has the uniform
distribution over the symmetric group, and when its distribution is constant on
cycle type.


title: Theory of the Raman spectrum of rotated double-layer graphene

abstract:
  We study theoretically the Raman spectrum of the rotated double-layer
graphene, consisting of two graphene layers rotated with respect to each other
by an arbitrary angle \theta. We find a relatively simple dependence of the
Raman G peak intensity on the angle \theta. On the other hand, the Raman 2D
peak position, intensity, and width show a much more complicated dependence on
the angle \theta. We account for all of these effects, including dependence on
the incoming photon energy, in good agreement with the experimental data. We
find that it is sufficient to include the interaction between the graphene
layers on the electronic degrees of freedom (resulting in the occurrence of van
Hove singularities in the density of states). We assume that the phonon degrees
of freedom are unaffected by the interaction between the layers. Furthermore,
we decompose the Raman 2D peak into two components having very different
linewidths; these widths are almost independent of the angle \theta. The change
in the intensity and the peak position of one of these two components gives
insight into the dependence of the overall Raman 2D peak features as a function
of the angle \theta. Additionally, we show regions in the phonon spectrum
giving rise to the Raman 2D peak signal. This work provides an insight into the
interplay between the mechanical degree of freedom (angle \theta) and the
electronic degrees of freedom (singularities in the density of states) in
rotated double-layer graphene. Additionally, this work provides a way to
establish experimentally the value of the rotation angle \theta using Raman
spectroscopy measurement. This procedure becomes even more robust if one
repeats the Raman spectroscopy measurement with a different incoming photon
energy.


title:
An Efficient Linear Programming Algorithm to Generate the Densest
  Lattice Sphere Packings

abstract:
  Finding the densest sphere packing in $d$-dimensional Euclidean space
$\mathbb{R}^d$ is an outstanding fundamental problem with relevance in many
fields, including the ground states of molecular systems, colloidal crystal
structures, coding theory, discrete geometry, number theory, and biological
systems. Numerically generating the densest sphere packings becomes very
challenging in high dimensions due to an exponentially increasing number of
possible sphere contacts and sphere configurations, even for the restricted
problem of finding the densest lattice sphere packings. In this paper, we apply
the Torquato-Jiao packing algorithm, which is a method based on solving a
sequence of linear programs, to robustly reproduce the densest known lattice
sphere packings for dimensions 2 through 19. We show that the TJ algorithm is
appreciably more efficient at solving these problems than previously published
methods. Indeed, in some dimensions, the former procedure can be as much as
three orders of magnitude faster at finding the optimal solutions than earlier
ones. We also study the suboptimal local density-maxima solutions (inherent
structures or "extreme" lattices) to gain insight about the nature of the
topography of the "density" landscape.


title: The Two Weight Inequality for the Hilbert Transform: A Primer

abstract:
  Recent work of Lacey-Sawyer-Shen-Uriarte-Tuero and Lacey have established a
conjecture of Nazarov-Treil-Volberg, giving a real-variable characterization of
the two weight inequality for the Hilbert transform, provided the pair of
weights do not share a common point mass.
  In this paper, the characterization is proved, collecting details from across
several papers, compactness is characterized, all relevant estimates are
proved, counterexamples are details, and areas of application are indicated.


title:
Weak Convergence Approach for Parabolic Equations with Large, Highly
  Oscillatory, Random Potential

abstract:
  This paper concerns the macroscopic behavior of solutions to parabolic
equations with large, highly oscillatory, random potential. When the
correlation function of the random potential satisfies a specific integrability
condition, we show that the random solution converges, as the correlation
length of the medium tends to zero, to the deterministic solution of a
homogenized equation in dimension $d\geq3$. Our derivation is based on a
Feynman-Kac probabilistic representation and the Kipnis-Varadhan method applied
to weak convergence of Brownian motions in random sceneries. For sufficiently
mixing coefficients, we also provide an optimal rate of convergence to the
homogenized limit using a quantitative martingale central limit theorem. As
soon as the above integrability condition fails, the solution is expected to
remain stochastic in the limit of a vanishing correlation length. For a large
class of potentials given as functionals of Gaussian fields, we show the
convergence of solutions to stochastic partial differential equations (SPDE)
with multiplicative noise. The Feynman-Kac representation and the corresponding
weak convergence of Brownian motions in random sceneries allows us to explain
the transition from deterministic to stochastic limits as a function of the
correlation function of the random potential.


title:
Revisiting the Triangulation Method for Pointing to Supernova and Failed
  Supernova with Neutrinos

abstract:
  In view of the advent of large-scale neutrino detectors such as IceCube, the
future Hyper-Kamiokande and the ones proposed for the Laguna project in Europe,
we re-examine the determination of the directional position of a Galactic
supernova by means of its neutrinos using the triangulation method. We study
the dependence of the pointing accuracy on the arrival time resolution of
supernova neutrinos at different detectors. For a failed supernova, we expect
better results due to the abrupt termination of the neutrino emission which
allows one to measure the arrival time with higher precision. We found that for
the time resolution of $\pm$ 2 (4) ms, the supernova can be located with a
precision of $\sim$ 5 (10)$^\circ$ on the declination and of $\sim$ 8
(15)$^\circ$ on the right ascension angle, if we combine the observations from
detectors at four different sites.


title: Building one-time memories from isolated qubits

abstract:
  One-time memories (OTM's) are simple tamper-resistant cryptographic devices,
which can be used to implement one-time programs, a very general form of
software protection and program obfuscation. Here we investigate the
possibility of building OTM's using quantum mechanical devices. It is known
that OTM's cannot exist in a fully-quantum world or in a fully-classical world.
Instead, we propose a new model based on "isolated qubits" -- qubits that can
only be accessed using local operations and classical communication (LOCC).
This model combines a quantum resource (single-qubit measurements) with a
classical restriction (on communication between qubits), and can be implemented
using current technologies, such as nitrogen vacancy centers in diamond. In
this model, we construct OTM's that are information-theoretically secure
against one-pass LOCC adversaries that use 2-outcome measurements.
  Our construction resembles Wiesner's old idea of quantum conjugate coding,
implemented using random error-correcting codes; our proof of security uses
entropy chaining to bound the supremum of a suitable empirical process. In
addition, we conjecture that our random codes can be replaced by some class of
efficiently-decodable codes, to get computationally-efficient OTM's that are
secure against computationally-bounded LOCC adversaries.
  In addition, we construct data-hiding states, which allow an LOCC sender to
encode an (n-O(1))-bit messsage into n qubits, such that at most half of the
message can be extracted by a one-pass LOCC receiver, but the whole message can
be extracted by a general quantum receiver.


title: Mechanisms of Zero-Lag Synchronization in Cortical Motifs

abstract:
  Zero-lag synchronization between distant cortical areas has been observed in
a diversity of experimental data sets and between many different regions of the
brain. Several computational mechanisms have been proposed to account for such
isochronous synchronization in the presence of long conduction delays: Of
these, the phenomenon of "dynamical relaying" - a mechanism that relies on a
specific network motif - has proven to be the most robust with respect to
parameter mismatch and system noise. Surprisingly, despite a contrary belief in
the community, the common driving motif is an unreliable means of establishing
zero-lag synchrony. Although dynamical relaying has been validated in empirical
and computational studies, the deeper dynamical mechanisms and comparison to
dynamics on other motifs is lacking. By systematically comparing
synchronization on a variety of small motifs, we establish that the presence of
a single reciprocally connected pair - a "resonance pair" - plays a crucial
role in disambiguating those motifs that foster zero-lag synchrony in the
presence of conduction delays (such as dynamical relaying) from those that do
not (such as the common driving triad). Remarkably, minor structural changes to
the common driving motif that incorporate a reciprocal pair recover robust
zero-lag synchrony. The findings are observed in computational models of
spiking neurons, populations of spiking neurons and neural mass models, and
arise whether the oscillatory systems are periodic, chaotic, noise-free or
driven by stochastic inputs. The influence of the resonance pair is also robust
to parameter mismatch and asymmetrical time delays amongst the elements of the
motif. We call this manner of facilitating zero-lag synchrony resonance-induced
synchronization, outline the conditions for its occurrence, and propose that it
may be a general mechanism to promote zero-lag synchrony in the brain.

categories: q-bio.NC cond-mat.dis-nn nlin.AO nlin.CD physics.bio-ph


title:
Measurement of the D*(2010)+ natural line width and the D*(2010)+ - D0
  mass difference

abstract:
  We measure the mass difference, \Delta m_0, between the D*(2010)+ and the D0
and the natural line width, \Gamma, of the transition D*(2010)+ -> D0 pi+. The
data were recorded with the BABAR detector at center-of-mass energies at and
near the Upsilon(4S) resonance, and correspond to an integrated luminosity of
approximately 477 1/fb. The D0 is reconstructed in the decay modes D0 -> K- pi+
and D0 -> K- pi+ pi- pi+. For the decay mode D0 -> K- pi+ we obtain Gamma =
(83.4 +- 1.7 +- 1.5) keV and \Delta m_0 = (145 425.6 +- 0.6 +- 1.8) keV, where
the quoted errors are statistical and systematic, respectively. For the D0 ->
K- pi+ pi- pi+ mode we obtain \Gamma = (83.2 +- 1.5 +- 2.6) keV and \Delta m_0
= (145 426.6 +- 0.5 +- 2.0) keV. The combined measurements yield \Gamma = (83.3
+- 1.2 +- 1.4) keV and \Delta m_0 = (145 425.9 +- 0.4 +- 1.7) keV; the width is
a factor of approximately 12 times more precise than the previous value, while
the mass difference is a factor of approximately 6 times more precise.


title:
Small-Bias Sets for Nonabelian Groups: Derandomizing the Alon-Roichman
  Theorem

abstract:
  In analogy with epsilon-biased sets over Z_2^n, we construct explicit
epsilon-biased sets over nonabelian finite groups G. That is, we find sets S
subset G such that | Exp_{x in S} rho(x)| <= epsilon for any nontrivial
irreducible representation rho. Equivalently, such sets make G's Cayley graph
an expander with eigenvalue |lambda| <= epsilon. The Alon-Roichman theorem
shows that random sets of size O(log |G| / epsilon^2) suffice. For groups of
the form G = G_1 x ... x G_n, our construction has size poly(max_i |G_i|, n,
epsilon^{-1}), and we show that a set S \subset G^n considered by Meka and
Zuckerman that fools read-once branching programs over G is also epsilon-biased
in this sense. For solvable groups whose abelian quotients have constant
exponent, we obtain epsilon-biased sets of size (log |G|)^{1+o(1)}
poly(epsilon^{-1}). Our techniques include derandomized squaring (in both the
matrix product and tensor product senses) and a Chernoff-like bound on the
expected norm of the product of independently random operators that may be of
independent interest.


title:
A new integral representation for the scalar products of Bethe states
  for the XXX spin chain

abstract:
  Based on the method of separation of variables due to Sklyanin, we construct
a new integral representation for the scalar products of the Bethe states for
the SU(2) XXX spin 1/2 chain obeying the periodic boundary condition. Due to
the compactness of the symmetry group, a twist matrix must be introduced at the
boundary in order to extract the separated variables properly. Then by deriving
the integration measure and the spectrum of the separated variables, we express
the inner product of an on-shell and an off-shell Bethe states in terms of a
multiple contour integral involving a product of Baxter wave functions. Its
form is reminiscent of the integral over the eigenvalues of a matrix model and
is expected to be useful in studying the semi-classical limit of the product.


title:
Inter-surface interaction via phonon in three-dimensional topological
  insulator

abstract:
  We theoretically study the phonon mediated intersurface electron-electron
interactions on the pseudo two-dimensional metallic states at the two surfaces
of a three-dimensional topological insulator. From a model of a
three-dimensional topological insulator including the phonon excitation in it,
we derive the effective Lagrangian which describes the two surface metallic
states and the interaction between them. The intersurface electron-electron
interactions can be either repulsive or attractive depending on parameters such
as temperature, the speed of the phonon, and the Fermi velocity of the surface
states. The attractive interaction removes the Dirac nodes from the two surface
states as a result of the spontaneous symmetry breaking. On the basis of the
calculated results, we also discuss how to tune the inter-surface interaction.


title:
Some partial results on the convergence of loop-erased random walk to
  SLE(2) in the natural parametrization

abstract:
  We outline a strategy for showing convergence of loop-erased random walk on
the Z^2 square lattice to SLE(2), in the supremum norm topology that takes the
time parametrization of the curves into account. The discrete curves are
parametrized so that the walker moves at a constant speed determined by the
lattice spacing, and the SLE(2) curve has the recently introduced natural time
parametrization. Our strategy can be seen as an extension of the one used by
Lawler, Schramm, and Werner to prove convergence modulo time parametrization.
The crucial extra step is showing that the expected occupation measure of the
discrete curve, properly renormalized by the chosen time parametrization,
converges to the occupation density of the SLE(2) curve, the so-called SLE
Green's function. Although we do not prove this convergence, we rigorously
establish some partial results in this direction including a new loop-erased
random walk estimate.


title:
Deep subwavelength beam propagation in extremely loss-anisotropic
  metamaterials

abstract:
  Metal-dielectric multilayer metamaterials with extreme loss-anisotropy, in
which the longitudinal component of the permittivity tensor has ultra-large
imaginary part, are proposed and designed. Diffraction-free deep subwavelength
beam propagation and manipulation, due to the nearly flat iso-frequency contour
(IFC), is demonstrated in such loss-anisotropic metamaterials. It is also shown
that deep subwavelength beam propagation can be realized in practical
multilayer structures with large multilayer period, when the nonlocal effect is
considered.


title:
Network Analysis and Application Control Software based on Client-Server
  Architecture

abstract:
  This paper outlines a comprehensive model to increase system efficiency,
preserve network bandwidth, monitor incoming and outgoing packets, ensure the
security of confidential files and reduce power wastage in an organization.
This model illustrates the use and potential application of a Network Analysis
Tool (NAT) in a multi-computer set-up of any scale. The model is designed to
run in the background and not hamper any currently executing applications,
while using minimum system resources. It was developed as open source software,
using VB. Net, with a view to overcoming limitations of legacy systems and
financial restrictions in small-to mid-level organizations like businesses and
educational institutes. It is fully-customizable and serves as a simple and
open-source alternative to existing software. The NAT relies on simple
client-server architecture and uses remote access to monitor and maintain the
computers on a network, for example logging off a user or shutting down a
computer after a certain "idle" time, enabling and disabling applications,
troubleshooting and so on. The NAT was tested in a laboratory and resultant
data is presented, along with the results of a survey that was conducted among
users.


title: Note on Bessel functions of type $A_{N-1}$

abstract:
  Through the theory of Jack polynomials we give an iterative method for
integral formula of Dunkl-Bessel functions of type $A_{N-1}$ and a partial
product formula for it.


title: Small Planetesimals in a Massive Disk Formed Mars

abstract:
  Mars is likely to be a planetary embryo formed through collisions with
planetesimals, which can explain its small mass and rapid formation timescale
obtained from 182Hf-182$W chronometry. In the classical theory of planet
formation, the final embryo mass is determined only by the solid surface
density. However, embryos can stir surrounding planetesimals, leading to
fragmentation through erosive (cratering) collisions. We find that radial drift
of small fragments can drastically reduce the solid surface density. On the
other hand, embryo growth is accelerated by fragment accretion. Since
collisional fragmentation efficiency depends on the initial size of
planetesimals, the final embryo mass and its growth time are determined by the
initial planetesimal size and disk surface density. We have investigated the
effect of these two parameters on the mass of Mars and the predicted radiogenic
excess of 182W in the martian mantle. Two scenarios can explain the rapid
formation of small Mars: (i) it formed by accretion of small planetesimals in a
massive disk or (ii) it formed from large planetesimals but its growth was
arrested by the inward then outward migration of Jupiter. Taking into account
all constraints, we conclude that Mars is likely to have formed in a massive
disk of about ~ 0.1 solar mass from planetesimals smaller than ~ 10 km in
radius. Such small planetesimal size cannot explain core accretion of Jupiter,
suggesting that there may have been a heliocentric gradient in planetesimal
size in the solar nebula.


title: Surface angular momentum of light beams

abstract:
  Traditionally, the angular momentum of light is calculated for "bullet-like"
electromagnetic wave packets, although in actual optical experiments
"pencil-like" beams of light are more commonly used. The fact that a wave
packet is bounded transversely and longitudinally while a beam has, in
principle, an infinite extent along the direction of propagation, renders
incomplete the textbook calculation of the spin/orbital separation of the
angular momentum of a light beam. In this work we demonstrate that a novel,
extra surface part must be added in order to preserve the gauge invariance of
the optical angular momentum per unit length. The impact of this extra term is
quantified by means of two examples: a Laguerre-Gaussian and a Bessel beam,
both circularly polarized.


title:
Nonlinear dynamical systems and bistability in linearly forced isotropic
  turbulence

abstract:
  In this letter, we present an extensive study of the linearly forced
isotropic turbulence. By using analytical method, we identify two parametric
choices, of which they seem to be new as far as our knowledge goes. We prove
that the underlying nonlinear dynamical system for linearly forced isotropic
turbulence is the general case of a cubic Lienard equation with linear damping.
We also discuss a Fokker-Planck approach to this new dynamical system,which is
bistable and exhibits two asymmetric and asymptotically stable stationary
probability densities.


title: Perfect Powers of Five with Few Ternary Digits

abstract:
  In this note we will analyze a diophantine equation raised by Michael Bennett
in [1] that is pivotal in establishing that powers of five has few digits in
its ternary expansion. We will show that the Diophantine equation
$3^{a}+3^{b}+2=n^5$, where $(n,3)=1$ and $a>b>0$ is insoluble for pairs of
positive integers $(a,b)$ where they are both even or one is even and the other
is odd. In the case where both $(a,b)$ are odd, there is one known solution
$2^5=3^3+3^1+2.$ We will show that there are no other solutions to the
diophantine equation for $n^{5}<32\left(1+3(10^6)\right)^5$.


title:
Tuning Jeff = 1/2 Insulating State via Electron Doping and Pressure in
  Double-Layered Iridate Sr3Ir2O7

abstract:
  Sr3Ir2O7 exhibits a novel Jeff=1/2 insulating state that features a splitting
between Jeff=1/2 and 3/2 bands due to spin-orbit interaction. We report a
metal-insulator transition in Sr3Ir2O7 via either dilute electron doping (La3+
for Sr2+) or application of high pressure up to 35 GPa. Our study of
single-crystal Sr3Ir2O7 and (Sr1-xLax)3Ir2O7 reveals that application of high
hydrostatic pressure P leads to a drastic reduction in the electrical
resistivity by as much as six orders of magnitude at a critical pressure, PC =
13.2 GPa, manifesting a closing of the gap; but further increasing P up to 35
GPa produces no fully metallic state at low temperatures, possibly as a
consequence of localization due to a narrow distribution of bonding angles
{\theta}. In contrast, slight doping of La3+ ions for Sr2+ ions in Sr3Ir2O7
readily induces a robust metallic state in the resistivity at low temperatures;
the magnetic ordering temperature is significantly suppressed but remains
finite for (Sr0.95La0.05)3Ir2O7 where the metallic state occurs. The results
are discussed along with comparisons drawn with Sr2IrO4, a prototype of the
Jeff = 1/2 insulator.