title:
Comprehensive Study of a z = 2.35 DLA Galaxy: Mass, Metallicity, Age,
  Morphology and SFR from HST and VLT

abstract:
  We present a detailed study of the emission from a z = 2.35 galaxy that
causes damped Lyman-alpha absorption in the spectrum of the background QSO,
SDSS J 2222-0946. We present the results of extensive analyses of the stellar
continuum covering the rest frame optical-UV regime based on broad-band HST
imaging, and of spectroscopy from VLT/X-Shooter of the strong emission lines:
Ly-alpha, [OII], [OIII], [NII], H-alpha and H-beta. We compare the metallicity
from the absorption lines in the QSO spectrum with the oxygen abundance
inferred from the strong-line methods (R23 and N2). The two emission-line
methods yield consistent results: [O/H] = -0.30+/-0.13. Based on the absorption
lines in the QSO spectrum a metallicity of -0.49+/-0.05 is inferred at an
impact parameter of 6.3 kpc from the centre of the galaxy with a column density
of hydrogen of log(N_HI)=20.65+/-0.05. The star formation rates of the galaxy
from the UV continuum and H-alpha line can be reconciled assuming an amount of
reddening of E(B-V) = 0.06+/-0.01, giving an inferred SFR of 13+/-1 M_sun / yr
(assuming a Chabrier IMF). From the HST imaging, the galaxy associated with the
absorption is found to be a compact (re=1.12 kpc) object with a disc-like,
elongated (axis ratio 0.17) structure indicating that the galaxy is seen close
to edge on. Moreover, the absorbing gas is located almost perpendicularly above
the disc of the galaxy suggesting that the gas causing the absorption is not
co-rotating with the disc. We investigate the stellar and dynamical masses from
SED-fitting and emission-line widths, respectively, and find consistent results
of 2x10^9 M_sun. We suggest that the galaxy is a young proto-disc with evidence
for a galactic outflow of enriched gas. This galaxy hints at how star-forming
galaxies may be linked to the elusive population of damped Lyman-alpha
absorbers.


title: HALOGAS: Extraplanar gas in NGC 3198

abstract:
  We present the analysis of new, deep HI observations of the spiral galaxy NGC
3198, as part of the HALOGAS (Westerbork Hydrogen Accretion in LOcal GAlaxieS)
survey, with the main aim of investigating the presence, amount, morphology and
kinematics of extraplanar gas. We present models of the HI observations of NGC
3198: the model that matches best the observed data cube features a thick disk
with a scale height of ~3 kpc and an HI mass of about 15% of the total HI mass;
this thick disk also has a decrease in rotation velocity as a function of
height (lag) of 7-15 km/s/kpc (though with large uncertainties). This
extraplanar gas is detected for the first time in NGC 3198. Radially, this gas
appears to extend slightly beyond the actively star-forming body of the galaxy
(as traced by the Halpha emission), but it is not more radially extended than
the outer, fainter parts of the stellar disk. Compared to previous studies,
thanks to the improved sensitivity we trace the rotation curve out to larger
radii. We model the rotation curve in the framework of MOND (Modified Newtonian
Dynamics) and we confirm that, with the allowed distance range we assumed, fit
quality is modest in this galaxy, but the new outer parts are explained in a
satisfactory way.


title: Top Partner Probes of Extended Higgs Sectors

abstract:
  Natural theories of the weak scale often include fermionic partners of the
top quark. If the electroweak symmetry breaking sector contains scalars beyond
a single Higgs doublet, then top partners can have sizable branching ratios to
these extended Higgs sector states. In fact, top partner decays may provide the
most promising discovery mode for such scalars, especially given the large
backgrounds to direct and associated production. In this paper, we present a
search strategy for top partner decays to a charged Higgs boson and a bottom
quark, focusing on the case where the charged Higgs dominantly decays to
third-generation quarks to yield a multi-b final state. We also discuss ways to
extend this search to exotic neutral scalars decaying to bottom quark pairs.


title:
What can we really learn about Magnetic Fields in Galaxy Clusters from
  Faraday Rotation observations?

abstract:
  We construct a simple and robust approach for deriving constraints on
magnetic fields in galaxy clusters from rotation measure (RM) maps. Relaxing
the commonly used assumptions of a correlation between the magnetic field
strength and the plasma density and of a power-law (in wave number) magnetic
field power spectrum, and using an efficient numerical analysis method, we test
the consistency of a wide range of magnetic field models with RM maps of 11
extended sources in 5 clusters, for which the data were made available to us.
We show that the data reveal no indication for a radial dependence of the
average magnetic field strength, and in particular no indication for a
correlation between the gas density and the field strength. The RM maps of a
considerable fraction of the sources either require or are consistent with the
presence of a spatially uniform magnetic field of a relatively small strength,
0.02-0.3 muG, which contributes significantly to the RM. The RM maps of all but
one source do not require a power-law magnetic field power spectrum, and most
are consistent with a power spectrum dominated by a single wave length. The
uncertainties in the magnetic field strengths (and spatial correlation lengths)
derived from RM maps exceed an order of magnitude (and often more). These
uncertainties imply, in particular, that there is no indication in current RM
data for a systematic difference between the magnetic field strengths in
radio-halo clusters and in radio-quiet clusters. With the improvement expected
in the near future of the quality and quantity of RM data, our analysis method
will enable one to derive more accurate constraints on magnetic fields in
galaxy clusters.


title: Urchin: A Reverse Ray Tracer for Astrophysical Applications

abstract:
  We describe URCHIN, a reverse ray tracing radiative transfer scheme optimised
to model self-shielding from the post-reionisation ultraviolet (UV) background
in cosmological simulations. The reverse ray tracing strategy provides several
benefits over forward ray tracing codes including: (1) the preservation of
adaptive density field resolution (2) completely uniform sampling of gas
elements by rays; (3) the preservation of galilean invariance; (4) the ability
to sample the UV background spectrum with hundreds of frequency bins; and (5)
exact preservation of the input UV background spectrum and amplitude in
optically thin gas. The implementation described here focuses on Smoothed
Particle Hydrodynamics (SPH). However, the method can be applied to any density
field representation in which resolution elements admit ray intersection tests
and can be associated with optical depths. We characterise the errors in our
implementation in stages beginning with comparison to known analytic solutions
and ending with a realistic model of the z = 3 cosmological UV background
incident onto a suite of spherically symmetric models of gaseous galactic
halos.


title:
Discovery of a Cosmological, Relativistic Outburst via its Rapidly
  Fading Optical Emission

abstract:
  We report the discovery by the Palomar Transient Factory (PTF) of the
transient source PTF11agg, which is distinguished by three primary
characteristics: (1) bright, rapidly fading optical transient emission; (2) a
faint, blue quiescent optical counterpart; and (3) an associated year-long,
scintillating radio transient. We argue that these observed properties are
inconsistent with any known class of Galactic transients, and instead suggest a
cosmological origin. The detection of incoherent radio emission at such
distances implies a large emitting region, from which we infer the presence of
relativistic ejecta. The observed properties are all consistent with the
population of long-duration gamma-ray bursts (GRBs), marking the first time
such an outburst has been discovered in the distant universe independent of a
high-energy trigger. We searched for possible high-energy counterparts to
PTF11agg, but found no evidence for associated prompt emission. We therefore
consider three possible scenarios to account for a GRB-like afterglow without a
high-energy counterpart: an "untriggered" GRB (lack of satellite coverage), an
"orphan" afterglow (viewing-angle effects), and a "dirty fireball" (suppressed
high-energy emission). The observed optical and radio light curves appear
inconsistent with even the most basic predictions for off-axis afterglow
models. The simplest explanation, then, is that PTF11agg is a normal, on-axis
long-duration GRB for which the associated high-energy emission was simply
missed. However, we have calculated the likelihood of such a serendipitous
discovery by PTF and find that it is quite small (~ 2.6%). While not
definitive, we nonetheless speculate that PTF11agg may represent a new, more
common (> 4 times the on-axis GRB rate at 90% confidence) class of relativistic
outbursts lacking associated high-energy emission.


title: Velocity Effects on an Accelerated Unruh-DeWitt Detector

abstract:
  We analyze the response of an Unruh-DeWitt detector moving along an unbounded
spatial trajectory in a two-dimensional spatial plane with constant independent
magnitudes of both the four-acceleration and of a timelike proper time
derivative of the four-accelration. In a Fermi-Walker frame moving with the
detector, the direction of the acceleration rotates at a constant rate around a
great circle. This is the motion of a charge in a uniform electric field when
in the frame of the charge there is both an electric and a magnetic field. We
compare the response of this detector to a detector moving with constant
velocity in a thermal bath of the corresponding temperature for
non-relativistic velocities, and in two regimes: ultraviolet and infrared. In
infrared regime, the detector in the Minkowski space-time moving along the
spatially two-dimensional trajectory should move with a higher speed to keep up
with the same excitation rate of the inertial detector in a thermal bath. In
ultraviolet regime, the dominant modification in the response of this detector
compared to the black body spectrum of Unruh radiation is the same as the
dominant modification perceived by a detector moving with constant velocity in
a thermal bath.


title: ISO(4,1) Symmetry in the EFT of Inflation

abstract:
  In DBI inflation the cubic action is a particular linear combination of the
two, otherwise independent, cubic operators \dot \pi^3 and \dot \pi (\partial_i
\pi)^2. We show that in the Effective Field Theory (EFT) of inflation this is a
consequence of an approximate 5D Poincar\'e symmetry, ISO(4,1), non-linearly
realized by the Goldstone \pi. This symmetry uniquely fixes, at lowest order in
derivatives, all correlation functions in terms of the speed of sound c_s. In
the limit c_s \to 1, the ISO(4,1) symmetry reduces to the Galilean symmetry
acting on \pi. On the other hand, we point out that the non-linear realization
of SO(4,2), the isometry group of 5D AdS space, does not fix the cubic action
in terms of c_s.


title:
The metallicity evolution of low mass galaxies: New constraints at
  intermediate redshift

abstract:
  We present abundance measurements from 26 emission-line selected galaxies at
z~0.6-0.7. By reaching stellar masses as low as 10^8 M_{\sun}, these
observations provide the first measurement of the intermediate redshift
mass-metallicity (MZ) relation below 10^9 M_{\sun} For the portion of our
sample above M > 10^9 M_{\sun} (8/26 galaxies), we find good agreement with
previous measurements of the intermediate redshift MZ relation. Compared to the
local relation, we measure an evolution that corresponds to a 0.12 dex decrease
in oxygen abundances at intermediate redshifts. This result confirms the trend
that metallicity evolution becomes more significant towards lower stellar
masses, in keeping with a downsizing scenario where low mass galaxies evolve
onto the local MZ relation at later cosmic times. We show that these galaxies
follow the local fundamental metallicity relation, where objects with higher
specific (mass-normalized) star formation rates (SFRs) have lower
metallicities. Furthermore, we show that the galaxies in our sample lie on an
extrapolation of the SFR-M_{*} relation (the star-forming main sequence).
Leveraging the MZ relation and star-forming main sequence (and combining our
data with higher mass measurements from the literature), we test models that
assume an equilibrium between mass inflow, outflow and star formation. We find
that outflows are required to describe the data. By comparing different outflow
prescriptions, we show that momentum driven winds can describe the MZ relation;
however, this model under-predicts the amount of star formation in low mass
galaxies. This disagreement may indicate that preventive feedback from
gas-heating has been overestimated, or it may signify a more fundamental
deviation from the equilibrium assumption.


title:
The COS/UVES Absorption Survey of the Magellanic Stream: I. One-Tenth
  Solar Abundances along the Body of the Stream

abstract:
  The Magellanic Stream (MS) is a massive and extended tail of multi-phase gas
stripped out of the Magellanic Clouds and interacting with the Galactic halo.
In this first paper of an ongoing program to study the Stream in absorption, we
present a chemical abundance analysis based on HST/COS and VLT/UVES spectra of
four AGN (RBS 144, NGC 7714, PHL 2525, and HE 0056-3622) lying behind the MS.
Two of these sightlines yield good MS metallicity measurements: toward RBS 144
we measure a low MS metallicity of [S/H]=[S II/H I]=-1.13+/-0.16 while toward
NGC 7714 we measure [O/H]=[O I/H I]=-1.24+/-0.20. Taken together with the
published MS metallicity toward NGC 7469, these measurements indicate a uniform
abundance of ~0.1 solar along the main body of the Stream. This provides strong
support to a scenario in which most of the Stream was tidally stripped from the
SMC ~1.5--2.5 Gyr ago (a time at which the SMC had a metallicity of ~0.1
solar), as predicted by several N-body simulations. However, in Paper II of
this series (Richter et al. 2013), we report a much higher metallicity (S/H=0.5
solar) in the inner Stream toward Fairall 9, a direction sampling a filament of
the MS that Nidever et al. (2008) claim can be traced kinematically to the LMC,
not the SMC. This shows that the bifurcation of the Stream is evident in its
metal enrichment. Finally we measure a similar low metallicity [O/H]=[O I/H
I]=-1.03+/-0.18 in the v_LSR=150 km/s cloud toward HE 0056--3622, which belongs
to a population of anomalous velocity clouds near the South Galactic Pole. This
suggests these clouds are associated with the Stream or more distant structures
(possibly the Sculptor Group, which lies in this direction at the same
velocity), rather than tracing foreground Galactic material.


title:
Methods for evaluating physical processes in strong external fields at
  e+e- colliders: Furry picture and quasi-classical approach

abstract:
  Future linear colliders designs, ILC and CLIC, are expected to be powerful
machines for the discovery of Physics Beyond the Standard Model and subsequent
precision studies. However, due to the intense beams (high luminosity, high
energy), strong electromagnetic fields occur in the beam-beam interaction
region. In the context of precision high energy physics, the presence of such
strong fields may yield sensitive corrections to the observed electron-positron
processes. The Furry picture of quantum states gives a conceptually simple tool
to treat physics processes in an external field. A generalization of the
quasi-classical operator method (QOM) as an approximation is considered too.


title:
The COS/UVES Absorption Survey of the Magellanic Stream: II. Evidence
  for a complex enrichment history of the Stream from the Fairall 9 sightline

abstract:
  We present a multi-wavelength study of the Magellanic Stream (MS), a massive
gaseous structure in the Local Group that is believed to represent material
stripped from the Magellanic Clouds. We use ultraviolet, optical and radio data
obtained with HST/COS, VLT/UVES, FUSE, GASS, and ATCA to study metal abundances
and physical conditions in the Stream toward the quasar Fairall 9. Line
absorption in the MS from a large number of metal ions and from molecular
hydrogen is detected in up to seven absorption components, indicating the
presence of multi-phase gas. From the analysis of unsaturated SII absorption,
in combination with a detailed photoionization model, we obtain a surprisingly
high alpha abundance in the Stream toward Fairall 9 of [S/H]=-0.30pm0.04 (0.5
solar). This value is 5 times higher than what is found along other MS
sightlines based on similar COS/UVES data sets. In contrast, the measured
nitrogen abundance is found to be substantially lower ([N/H]=-1.15pm0.06),
implying a very low [N/alpha] ratio of -0.85 dex. The substantial differences
in the chemical composition of MS toward Fairall 9 compared to other sightlines
point toward a complex enrichment history of the Stream. We favour a scenario,
in which the gas toward Fairall 9 was locally enriched with alpha elements by
massive stars and then was separated from the Magellanic Clouds before the
delayed nitrogen enrichment from intermediate-mass stars could set in. Our
results support (but do not require) the idea that there is a metal-enriched
filament in the Stream toward Fairall 9 that originates in the LMC.


title: Range Counting Coresets for Uncertain Data

abstract:
  We study coresets for various types of range counting queries on uncertain
data. In our model each uncertain point has a probability density describing
its location, sometimes defined as k distinct locations. Our goal is to
construct a subset of the uncertain points, including their locational
uncertainty, so that range counting queries can be answered by just examining
this subset. We study three distinct types of queries. RE queries return the
expected number of points in a query range. RC queries return the number of
points in the range with probability at least a threshold. RQ queries returns
the probability that fewer than some threshold fraction of the points are in
the range. In both RC and RQ coresets the threshold is provided as part of the
query. And for each type of query we provide coreset constructions with
approximation-size tradeoffs. We show that random sampling can be used to
construct each type of coreset, and we also provide significantly improved
bounds using discrepancy-based approaches on axis-aligned range queries.


title: Initial conditions and sampling for multifield inflation

abstract:
  We investigate the initial conditions problem for multifield inflation. In
these scenarios the pre-inflationary dynamics can be chaotic, increasing the
sensitivity of the onset of inflation to the initial data even in the
homogeneous limit. To analyze physically equivalent scenarios we compare
initial conditions at fixed energy. This ensures that each trajectory is
counted once and only once, since the energy density decreases monotonically.
We present a full analysis of hybrid inflation that reveals a greater degree of
long range order in the set of "successful" initial conditions than was
previously apparent. We explore the effective smoothing scale for the fractal
set of successful initial conditions induced by the finite duration of the
pre-inflationary phase. The role of the prior information used to specify the
initial data is discussed in terms of Bayesian sampling.


title:
The Fueling Diagram: Linking Galaxy Molecular-to-Atomic Gas Ratios to
  Interactions and Accretion

abstract:
  To assess how external factors such as local interactions and fresh gas
accretion influence the global ISM of galaxies, we analyze the relationship
between recent enhancements of central star formation and total
molecular-to-atomic (H2/HI) gas ratios, using a broad sample of field galaxies
spanning early-to-late type morphologies, stellar masses of 10^(7.2-11.2) Msun,
and diverse stages of evolution. We find that galaxies occupy several loci in a
"fueling diagram" that plots H2/HI vs. mass-corrected blue-centeredness, a
metric tracing the degree to which galaxies have bluer centers than the average
galaxy at their stellar mass. Spiral galaxies show a positive correlation
between H2/HI and mass-corrected blue-centeredness. When combined with previous
results linking mass-corrected blue-centeredness to external perturbations,
this correlation suggests a link between local galaxy interactions and
molecular gas inflow/replenishment. Intriguingly, E/S0 galaxies show a more
complex picture: some follow the same correlation, some are quenched, and a
distinct population of blue-sequence E/S0 galaxies (with masses below key
transitions in gas richness) defines a separate loop in the fueling diagram.
This population appears to be composed of low-mass merger remnants currently in
late- or post-starburst states, in which the burst first consumes the H2 while
the galaxy center keeps getting bluer, then exhausts the H2, at which point the
burst population reddens as it ages. Multiple lines of evidence suggest
connected evolutionary sequences in the fueling diagram. In particular,
tracking total gas-to-stellar mass ratios within the diagram provides evidence
of fresh gas accretion onto low-mass E/S0s emerging from central starbursts.
Drawing on a comprehensive literature search, we suggest that virtually all
galaxies follow the same evolutionary patterns found in our broad sample.


title: Minkowski decomposition of Okounkov bodies on surfaces

abstract:
  We prove that the Okounkov body of a big divisor with respect to a general
flag on a smooth projective surface whose pseudo-effective cone is rational
polyhedral decomposes as the Minkowski sum of finitely many simplices and line
segments arising as Okounkov bodies of nef divisors.


title:
A comprehensive chemical abundance study of the outer halo globular
  cluster M 75

abstract:
  Context: M 75 is a relatively young Globular Cluster (GC) found at 15 kpc
from the Galactic centre at the transition region between the inner and outer
Milky Way halos. Aims: Our aims are to perform a comprehensive abundance study
of a variety of chemical elements in this GC such as to investigate its
chemical enrichment history in terms of early star formation, and to search for
any multiple populations. Methods: We have obtained high resolution
spectroscopy with the MIKE instrument at the Magellan telescope for 16 red
giant stars. Their membership within the GC is confirmed from radial velocity
measurements. Our chemical abundance analysis is performed via equivalent width
measurements and spectral synthesis, assuming local thermodynamic equilibrium
(LTE). Results: We present the first comprehensive abundance study of M 75 to
date. The cluster is metal-rich ([Fe/H]=-1.16+/-0.02 dex,
[alpha/Fe]=+0.30+/-0.02 dex), and shows a marginal spread in [Fe/H] of 0.07
dex, typical of most GCs of similar luminosity. A moderately extended O-Na
anticorrelation is clearly visible, likely showing three generations of stars,
formed on a short timescale. Additionally the two most Na-rich stars are also
Ba-enhanced by 0.4 and 0.6 dex, respectively, indicative of pollution by lower
mass (M ~ 4-5 M_Sun) Asymptotic Giant Branch (AGB) stars. The overall n-capture
element pattern is compatible with predominant r-process enrichment, which is
rarely the case in GCs of such a high metallicity.


title: The ELM Survey. V. Merging Massive White Dwarf Binaries

abstract:
  We present the discovery of 17 low mass white dwarfs (WDs) in short-period
P<1 day binaries. Our sample includes four objects with remarkable log(g)~5
surface gravities and orbital solutions that require them to be double
degenerate binaries. All of the lowest surface gravity WDs have metal lines in
their spectra implying long gravitational settling times or on-going accretion.
Notably, six of the WDs in our sample have binary merger times <10 Gyr. Four
have >=0.9 Msun companions. If the companions are massive WDs, these four
binaries will evolve into stable mass transfer AM CVn systems and possibly
explode as underluminous supernovae. If the companions are neutron stars, then
these may be milli-second pulsar binaries. These discoveries increase the
number of detached, double degenerate binaries in the ELM Survey to 54; 31 of
these binaries will merge within a Hubble time.


title: Non-Fermi liquids and the Wiedemann-Franz law

abstract:
  A general discussion of the ratio of thermal and electrical conductivities in
non-Fermi liquid metals is given. In metals with sharp Drude peaks, the
relevant physics is correctly organized around the slow relaxation of
almost-conserved momenta. While in Fermi liquids both currents and momenta
relax slowly, due to the weakness of interactions among low energy excitations,
in strongly interacting non-Fermi liquids typically only momenta relax slowly.
It follows that the conductivities of such non-Fermi liquids are obtained
within a fundamentally different kinematics to Fermi liquids. Among these
strongly interacting non-Fermi liquids we distinguish cases with only one
almost-conserved momentum, which we term hydrodynamic metals, and with many
patchwise almost-conserved momenta. For all these cases, we obtain universal
expressions for the ratio of conductivities that violate the Wiedemann-Franz
law. We further discuss the case in which long-lived `cold' quasiparticles, in
general with unconventional scattering rates, coexist with strongly interacting
hot spots, lines or bands. For these cases, we characterize circumstances under
which non-Fermi liquid transport, in particular a linear in temperature
resistivity, is and is not compatible with the Wiedemann-Franz law. We suggest
the likely outcome of future transport experiments on CeCoIn5, YbRh2Si2 and
Sr3Ru2O7 at their critical magnetic fields.


title:
A scaling-relation for disc galaxies: circular-velocity gradient versus
  central surface brightness

abstract:
  For disc galaxies, a close relation exists between the distribution of light
and the shape of the rotation curve. We quantify this relation by measuring the
inner circular-velocity gradient d_{R}V(0) for spiral and irregular galaxies
with high-quality rotation curves. We find that d_{R}V(0) correlates with the
central surface brightness mu_{0} over more than two orders of magnitude in
d_{R}V(0) and four orders of magnitudes in mu_{0}. This is a scaling-relation
for disc galaxies. It shows that the central stellar density of a galaxy
closely relates to the inner shape of the potential well, also for
low-luminosity and low-surface-brightness galaxies that are expected to be
dominated by dark matter.


title:
Extra Spin Asymmetries From the Breakdown of TMD-Factorization in
  Hadron-Hadron Collisions

abstract:
  We demonstrate that partonic correlations that would traditionally be
identified as subleading on the basis of a generalized TMD-factorization
conjecture can become leading-power because of TMD-factorization breaking that
arises in hadron-hadron collisions with large transverse momentum back-to-back
hadrons produced in the final state. General forms of TMD-factorization fail
for such processes because of a previously noted incompatibility between the
requirements for TMD-factorization and the Ward identities of non-Abelian gauge
theories. We first review the basic steps for factorizing the gluon
distribution and then show that a conflict between TMD-factorization and the
non-Abelian Ward identity arises already at the level of a single extra soft or
collinear gluon when the partonic subprocess involves a TMD gluon distribution.
Next we show that the resulting TMD-factorization violating effects produce
leading-power final state spin asymmetries that would be classified as
subleading in a generalized TMD-factorization framework. We argue that similar
extra TMD-factorization breaking effects may be necessary to explain a range of
open phenomenological QCD puzzles. The potential to observe extra transverse
spin or azimuthal asymmetries in future experiments is highlighted as their
discovery may indicate an influence from novel and unexpected large distance
parton correlations.


title: An sl(2, R) current algebra from AdS_3 gravity

abstract:
  We provide a set of chiral boundary conditions for three-dimensional gravity
that allow for asymptotic symmetries identical to those of two-dimensional
induced gravity in light-cone gauge considered by Polyakov. These are the most
general boundary conditions consistent with the boundary terms introduced by
Compere, Song and Strominger recently. We show that the asymptotic symmetry
algebra of our boundary conditions is an sl(2,R) current algebra with level
given by c/6. The fully non-linear solution in Fefferman--Graham coordinates is
also provided along with its charges.


title:
The X-ray under-luminosity of the O-type supergiants HD16691 and HD14947
  revealed by XMM-Newton

abstract:
  The members of the scarce category of Of^+ supergiants present properties
that are intermediate between regular O-stars and Wolf-Rayet (WR) stars.
Significant similarities between these transitional stars and WN-type objects
are now clearly established, at least in the visible and near-infrared domains,
pointing to common stellar wind properties. In this study, we report on the
first dedicated X-ray observations of HD16691 (O4If^+) and HD14947 (O5f^+),
revealing a soft thermal spectrum in agreement with the expected X-ray emission
from a single O-type star. However, the X-ray luminosity of our targets is
slightly lower than expected for single O-type stars, suggesting that the
particular properties of their stellar wind has also a significant impact on
the X-ray emission of these objects on the way to the WN category. We argue
that the X-ray under-luminosity of HD16691 and HD14947 may be interpreted as
the signature in X-rays of the intermediate stage between O and WR stars, as a
consequence of enhanced wind density.


title: Using Megamaser Disks to Probe Black Hole Accretion

abstract:
  We examine the alignment between H_2O megamaser disks on sub-pc scales with
circumnuclear disks and bars on <500 pc scales observed with HST/WFC3. The HST
imaging reveals young stars, indicating the presence of gas. The megamaser
disks are not well aligned with the circumnuclear bars or disks as traced by
stars in the HST images. We speculate on the implications of the observed
misalignments for fueling supermassive black holes in gas-rich spiral galaxies.
In contrast, we find a strong preference for the rotation axes of the megamaser
disks to align with radio continuum jets observed on >50 pc scales, in those
galaxies for which radio continuum detections are available. Sub-arcsecond
observations of molecular gas with ALMA will enable a more complete
understanding of the interplay between circumnuclear structures.


title:
Microscopic Theory of a Quantum Hall Ising Nematic: Domain Walls and
  Disorder

abstract:
  We study the the interplay between spontaneously broken valley symmetry and
spatial disorder in multivalley semiconductors in the quantum Hall regime. In
cases where valleys have anisotropic electron dispersion a previous
long-wavelength analysis [Phys. Rev. B 82, 035428 (2010)] identified two new
phases exhibiting the QHE. The first is the quantum Hall Ising nematic (QHIN),
a phase with long-range orientational order manifested in macroscopic transport
anisotropies. The second is the quantum Hall random-field paramagnet (QHRFPM)
that emerges when the Ising ordering is disrupted by quenched disorder,
characterized by a domain structure with a distinctive response to a valley
symmetry-breaking strain field. Here we provide a more detailed microscopic
analysis of the QHIN, which allows us to (i) estimate its Ising ordering
temperature; (ii) study its domain-wall excitations, which play a central role
in determining its properties; and (iii) analyze its response to quenched
disorder from impurity scattering, which gives an estimate for domain size in
the descendant QHRFPM. Our results are directly applicable to AlAs
heterostructures, although their qualitative aspects inform other ferromagnetic
QH systems, such as Si(111) heterostructures and bilayer graphene with trigonal
warping.


title: A Dust-Obscured Massive Maximum-Starburst Galaxy at a Redshift of 6.34

abstract:
  Massive present-day early-type (elliptical and lenticular) galaxies probably
gained the bulk of their stellar mass and heavy elements through intense,
dust-enshrouded starbursts - that is, increased rates of star formation - in
the most massive dark matter halos at early epochs. However, it remains unknown
how soon after the Big Bang such massive starburst progenitors exist. The
measured redshift distribution of dusty, massive starbursts has long been
suspected to be biased low in redshift owing to selection effects, as confirmed
by recent findings of systems out to redshift z~5. Here we report the
identification of a massive starburst galaxy at redshift 6.34 through a
submillimeter color-selection technique. We unambiguously determined the
redshift from a suite of molecular and atomic fine structure cooling lines.
These measurements reveal a hundred billion solar masses of highly excited,
chemically evolved interstellar medium in this galaxy, which constitutes at
least 40% of the baryonic mass. A "maximum starburst" converts the gas into
stars at a rate more than 2,000 times that of the Milky Way, a rate among the
highest observed at any epoch. Despite the overall downturn of cosmic star
formation towards the highest redshifts, it seems that environments mature
enough to form the most massive, intense starbursts existed at least as early
as 880 million years after the Big Bang.


title: Markov bases and generalized Lawrence liftings

abstract:
  Minimal Markov bases of configurations of integer vectors correspond to
minimal binomial generating sets of the assocciated lattice ideal. We give
necessary and sufficient conditions for the elements of a minimal Markov basis
to be (a) inside the universal Gr{\" o}bner basis and (b) inside the Graver
basis. We study properties of Markov bases of generalized Lawrence liftings for
arbitrary matrices $A\in\mathcal{M}_{m\times n}(\Bbb{Z})$ and
$B\in\mathcal{M}_{p\times n}(\Bbb{Z})$ and show that in cases of interest the
{\em complexity} of any two Markov bases is the same.


title: Competing supersolids of Bose-Bose mixtures in a triangular lattice

abstract:
  We study the ground state properties of a frustrated two-species mixture of
hard-core bosons on a triangular lattice, as a function of tunable amplitudes
for tunnelling and interactions. By combining three different methods, a
self-consistent cluster mean-field, exact diagonalizations and effective
theories, we unravel a very rich and complex phase diagram. More specifically,
we discuss the existence of three original mixture supersolids: (i) a
commensurate with frozen densities and supersolidity in spin degrees of
freedom, in a regime of strong interspecies interactions; and (ii) when this
interaction is weaker, two mutually competing incommensurate supersolids.
Finally, we show how these phases can be stabilized by a quantum fluctuation
enhancement of peculiar insulating parent states.


title:
Canonical representatives for divisor classes on tropical curves and the
  Matrix-Tree Theorem

abstract:
  Let $\Gamma$ be a compact tropical curve (or metric graph) of genus $g$.
Using the theory of tropical theta functions, Mikhalkin and Zharkov proved that
there is a canonical effective representative (called a break divisor) for each
linear equivalence class of divisors of degree $g$ on $\Gamma$. We present a
new combinatorial proof of the fact that there is a unique break divisor in
each equivalence class, establishing in the process an "integral" version of
this result which is of independent interest. As an application, we provide a
"geometric proof" of (a dual version of) Kirchhoff's celebrated Matrix-Tree
Theorem. Indeed, we show that each weighted graph model $G$ for $\Gamma$ gives
rise to a canonical polyhedral decomposition of the $g$-dimensional real torus
${\rm Pic}^g(\Gamma)$ into parallelotopes $C_T$, one for each spanning tree $T$
of $G$, and the dual Kirchhoff theorem becomes the statement that the volume of
${\rm Pic}^g(\Gamma)$ is the sum of the volumes of the cells in the
decomposition.


title:
The quasi-state space of a C*-algebra is a topological quotient of the
  representation space

abstract:
  We show that for any C*-algebra $A$, a sufficiently large Hilbert space $H$
and a unit vector $\xi \in H$, the natural application $rep(A:H) \to Q(A)$,
$\pi \mapsto \langle \pi(-)\xi,\xi \rangle$ is a topological quotient, where
$rep(A:H)$ is the space of representations on $H$ and $Q(A)$ the set of
quasi-states, i.e. positive linear functionals with norm at most $1$. This
quotient might be a useful tool in the representation theory of C*-algebras. We
apply it to give an interesting proof of Takesaki-Bichteler duality for
C*-algebras which allows to drop a hypothesis.


title: A short proof of d'Alemberts theorem

abstract:
  A classical theorem of d'Alembert states that if a polynomial P(x) with real
coefficients has a non-real root x=a+ib, then it also has a root x=a-ib. We
give a short and elementary inductive proof that avoids any properties of the
complex conjugation operator.


title: Probing the perturbative dynamics of exclusive meson pair production

abstract:
  We present the results of a recent novel application of the `hard exclusive'
perturbative formalism to the process gg --> MMbar at large angles, where M
(Mbar) is a light meson (anti-meson). As well as discussing the important
theoretical features of the relevant leading-order gg --> qqbar(gg) qqbar(gg)
6-parton amplitudes, we also comment on their phenomenological implications. In
particular, we consider the central exclusive production of meson pairs at
comparatively large transverse momentum k_t, which is expected to proceed via
this mechanism. We show that this leads to various non-trivial predictions for
a range of exclusive processes, and that the cross sections for the eta' and
eta mesons display significant sensitivity to any valence gg component of the
meson wavefunctions.


title: On the K-theory of groups with Finite Decomposition Complexity

abstract:
  It is proved that the assembly map in algebraic K- and L-theory with respect
to the family of finite subgroups is injective for groups $\Gamma$ with finite
quotient finite decomposition complexity (a strengthening of finite
decomposition complexity introduced by Guentner, Tesser and Yu) that admit a
finite dimensional model for $\underbar E\Gamma$ and have an upper bound on the
order of their finite subgroups. In particular this applies to finitely
generated linear groups over fields with characteristic zero with a finite
dimensional model for $\underbar E\Gamma$.


title:
Extended solutions of the harmonic map equation in the special unitary
  group

abstract:
  We classify all harmonic maps of finite uniton number from a Riemann surface
into SU(n) in terms of certain pieces of the Bruhat decomposition of the
subgroup of algebraic loops in SU(n). We give a description of the "Frenet
frame data" for such harmonic maps in a given class.


title:
CFHTLenS: The relation between galaxy dark matter haloes and baryons
  from weak gravitational lensing

abstract:
  We present a study of the relation between dark matter halo mass and the
baryonic content of host galaxies, quantified via luminosity and stellar mass.
Our investigation uses 154 deg2 of Canada-France-Hawaii Telescope Lensing
Survey (CFHTLenS) lensing and photometric data, obtained from the CFHT Legacy
Survey. We employ a galaxy-galaxy lensing halo model which allows us to
constrain the halo mass and the satellite fraction. Our analysis is limited to
lenses at redshifts between 0.2 and 0.4. We express the relationship between
halo mass and baryonic observable as a power law. For the luminosity-halo mass
relation we find a slope of 1.32+/-0.06 and a normalisation of
1.19+0.06-0.07x10^13 h70^-1 Msun for red galaxies, while for blue galaxies the
best-fit slope is 1.09+0.20-0.13 and the normalisation is 0.18+0.04-0.05x10^13
h70^-1 Msun. Similarly, we find a best-fit slope of 1.36+0.06-0.07 and a
normalisation of 1.43+0.11-0.08x10^13 h70^-1 Msun for the stellar mass-halo
mass relation of red galaxies, while for blue galaxies the corresponding values
are 0.98+0.08-0.07 and 0.84+0.20-0.16x10^13 h70^-1 Msun. For red lenses, the
fraction which are satellites tends to decrease with luminosity and stellar
mass, with the sample being nearly all satellites for a stellar mass of 2x10^9
h70^-2 Msun. The satellite fractions are generally close to zero for blue
lenses, irrespective of luminosity or stellar mass. This, together with the
shallower relation between halo mass and baryonic tracer, is a direct
confirmation from galaxy-galaxy lensing that blue galaxies reside in less
clustered environments than red galaxies. We also find that the halo model,
while matching the lensing signal around red lenses well, is prone to
over-predicting the large-scale signal for faint and less massive blue lenses.
This could be a further indication that these galaxies tend to be more isolated
than assumed. [abridged]


title:
An ALMA survey of submillimeter galaxies in the Extended Chandra Deep
  Field South: Source catalog and multiplicity

abstract:
  We present an Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 0
survey of 126 submillimeter sources from the LABOCA ECDFS Submillimeter Survey
(LESS). Our 870 micron survey with ALMA (ALESS) has produced maps ~3X deeper
and with a beam area ~200X smaller than the original LESS observations,
doubling the current number of interferometrically-observed submillimeter
sources. The high resolution of these maps allows us to resolve sources that
were previously blended and accurately identify the origin of the submillimeter
emission. We discuss the creation of the ALESS submillimeter galaxy (SMG)
catalog, including the main sample of 99 SMGs and a supplementary sample of 32
SMGs. We find that at least 35% (possibly up to 50%) of the detected LABOCA
sources have been resolved into multiple SMGs, and that the average number of
SMGs per LESS source increases with LESS flux density. Using the (now precisely
known) SMG positions, we empirically test the theoretical expectation for the
uncertainty in the single-dish source positions. We also compare our catalog to
the previously predicted radio/mid-infrared counterparts, finding that 45% of
the ALESS SMGs were missed by this method. Our ~1.6" resolution allows us to
measure a size of ~9 kpc X 5 kpc for the rest-frame ~300 um emission region in
one resolved SMG, implying a star formation rate surface density of 80 M_sol
yr^-1 kpc^-2, and we constrain the emission regions in the remaining SMGs to be
<10 kpc. As the first statistically reliable survey of SMGs, this will provide
the basis for an unbiased multiwavelength study of SMG properties.


title: Inclusion Logic and Fixed Point Logic

abstract:
  We investigate the properties of Inclusion Logic, that is, First Order Logic
with Team Semantics extended with inclusion dependencies. We prove that
Inclusion Logic is equivalent to Greatest Fixed Point Logic, and we prove that
all union-closed first-order definable properties of relations are definable in
it. We also provide an Ehrenfeucht-Fra\"iss\'e game for Inclusion Logic, and
give an example illustrating its use.


title:
Spontaneous time-reversal symmetry breaking in the boundary Majorana
  flat bands

abstract:
  We study the boundary Majorana modes for the single component p-wave weak
topological superconductors or superfluids, which form zero energy flat bands
protected by time-reversal symmetry in the orbital channel. However, due to the
divergence of density of states, the band flatness of the edge Majorana modes
is unstable under spontaneously generated spatial variations of Cooper pairing
phases. Staggered current loops appear near the boundary and thus time-reversal
symmetry is spontaneously broken in the orbital channel. This effect can appear
in both condensed matter and ultra-cold atom systems.

categories: cond-mat.supr-con cond-mat.mes-hall cond-mat.quant-gas cond-mat.str-el


title:
Energy dissipation in DC-field driven electron lattice coupled to
  fermion baths

abstract:
  Electron transport in electric-field-driven tight-binding lattice coupled to
fermion baths is comprehensively studied. We reformulate the problem by using
the scattering state method within the Coulomb gauge. Calculations show that
the formulation justifies direct access to the steady-state bypassing the
time-transient calculations, which then makes the steady-state methods
developed for quantum dot theories applicable to lattice models. We show that
the effective temperature of the hot-electron induced by a DC electric field
behaves as $T_{\rm eff}=C\gamma(\Omega/\Gamma)$ with a numerical constant $C$,
tight-binding parameter $\gamma$, the Bloch oscillation frequency $\Omega$ and
the damping parameter $\Gamma$. In the small damping limit $\Gamma/\Omega\to
0$, the steady-state has a singular property with the electron becoming
extremely hot in an analogy to the short-circuit effect. This leads to the
conclusion that the dissipation mechanism cannot be considered as an implicit
process, as treated in equilibrium theories. Finally, using the energy flux
relation, we derive a steady-state current for interacting models where only
on-site Green's functions are necessary.


title:
Steady-State Entanglement by Engineered Quasi-Local Markovian
  Dissipation

abstract:
  We characterize and construct time-independent Markovian dynamics that drive
a finite-dimensional multipartite quantum system into a target (pure) entangled
steady state, subject to physical locality constraints. In situations where the
desired stabilization task can not be attained solely based on local
dissipative means, we allow for local Hamiltonian control or, if the latter is
not an option, we suitably restrict the set of admissible initial states. In
both cases, we provide algorithms for constructing a master equation that
achieves the intended objective and show how this can genuinely extend the
manifold of stabilizable states. In particular, we present quasi-local control
protocols for dissipatively engineering multipartite GHZ "cat" states and W
states on $n$ qubits. For GHZ states, we find that no scalable procedure exists
for achieving stabilization from arbitrary initial states, whereas this is
possible for a target W state by a suitable combination of a two-body
Hamiltonian and dissipators. Interestingly, for both entanglement classes, we
show that quasi-local stabilization may be scalably achieved conditional to
initialization of the system in a large, appropriately chosen subspace.


title: Rankin-Selberg methods for closed strings on orbifolds

abstract:
  In recent work we have developed a new unfolding method for computing
one-loop modular integrals in string theory involving the Narain partition
function and, possibly, a weak almost holomorphic elliptic genus. Unlike the
traditional approach, the Narain lattice does not play any role in the
unfolding procedure, T-duality is kept manifest at all steps, a choice of Weyl
chamber is not required and the analytic structure of the amplitude is
transparent. In the present paper, we generalise this procedure to the case of
Abelian Z_N orbifolds, where the integrand decomposes into a sum of orbifold
blocks that can be organised into orbits of the Hecke congruence subgroup
{\Gamma}_0(N). As a result, the original modular integral reduces to an
integral over the fundamental domain of {\Gamma}_0(N), which we then evaluate
by extending our previous techniques. Our method is applicable, for instance,
to the evaluation of one-loop corrections to BPS-saturated couplings in the low
energy effective action of closed string models, of quantum corrections to the
K\"ahler metric and, in principle, of the free-energy of superstring vacua.


title: Free Convex Algebraic Geometry

abstract:
  This chapter is a tutorial on techniques and results in free convex algebraic
geometry and free real algebraic geometry (RAG). The term free refers to the
central role played by algebras of noncommutative polynomials R<x> in free
(freely noncommuting) variables x=(x_1,...,x_g). The subject pertains to
problems where the unknowns are matrices or Hilbert space operators as arise in
linear systems engineering and quantum information theory.
  The subject of free RAG flows in two branches. One, free positivity and
inequalities is an analog of classical real algebraic geometry, a theory of
polynomial inequalities embodied in algebraic formulas called
Positivstellens\"atze; often free Positivstellens\"atze have cleaner statements
than their commutative counterparts. Free convexity, the second branch of free
RAG, arose in an effort to unify a torrent of ad hoc optimization techniques
which came on the linear systems engineering scene in the mid 1990's.
Mathematically, much as in the commutative case, free convexity is connected
with free positivity through the second derivative: A free polynomial is convex
if and only if its Hessian is positive. However, free convexity is a very
restrictive condition, for example, free convex polynomials have degree 2 or
less.
  This article describes for a beginner techniques involving free convexity. As
such it also serves as a point of entry into the larger field of free real
algebraic geometry.


title: The Quartic Public Key Transformation

abstract:
  This paper presents the quartic public key transformation which can be used
for public key applications if side information is also used. This extends an
earlier work where the cubic transformation was similarly used. Such a
transformation can be used in multiparty communications protocols.


title:
Entropic stabilization of the folded states of RNA due to macromolecular
  crowding

abstract:
  We review the effects of macromolecular crowding on the folding of RNA by
considering the simplest scenario when excluded volume interactions between
crowding particles and RNA dominate. Using human telomerase enzyme as an
example, we discuss how crowding can alter the equilibrium between pseudoknot
and hairpin states of the same RNA molecule - a key aspect of crowder-RNA
interactions. We summarize data showing that the crowding effect is significant
only if the size of the spherical crowding particle is smaller than the radius
of gyration of the RNA in the absence of crowding particles. The implication
for function of the wild type and mutants of human telomerase is outlined by
using a relationship between enzyme activity and its conformational
equilibrium. In addition, we discuss the interplay between macromolecular
crowding and ionic strength of the RNA buffer. Finally, we briefly review
recent experiments which illustrate the connection between excluded volume due
to macromolecular crowding and the thermodynamics of RNA folding.


title:
Biased cosmological parameter estimation with galaxy cluster counts in
  the presence of primordial non-Gaussianities

abstract:
  The redshift dependence of the abundance of galaxy clusters is very sensitive
to the statistical properties of primordial density perturbations. It can thus
be used to probe small deviations from Gaussian initial conditions. Such
deviations constitute a very important signature of many inflationary
scenarios, and are thus expected to provide crucial information on physical
processes which took place in the very early Universe.
  We have determined the biases which may be introduced in the estimation of
cosmological parameters by wrongly assuming the absence of primordial
non-Gaussianities. Although we find that the estimation of the present-day dark
energy density using cluster counts is not very sensitive to the non-Gaussian
properties of the density field, we show that the biases can be considerably
larger in the estimation of the dark energy equation of state parameter $w$ and
of the amplitude of the primordial density perturbations.
  Our results suggest that a significant level of non-Gaussianity at cluster
scales may be able to reconcile the constraint on the amplitude of the
primordial perturbations obtained using galaxy cluster number counts from the
Planck Sunyaev-Zeldovich Catalog with that obtained from the primary Cosmic
Microwave Background anisotropies measured by the Planck satellite.


title: Pions: Experimental Tests of Chiral Symmetry Breaking

abstract:
  Based on the spontaneous breaking of chiral symmetry, chiral perturbation
theory (ChPT) is believed to approximate confinement scale QCD. Dedicated and
increasingly accurate experiments and improving lattice calculations are
confirming this belief, and we are entering a new era in which we can test
confinement scale QCD in some well chosen reactions. This is demonstrated with
an overview of low energy experimental tests of ChPT predictions of $\pi\pi$
scattering, pion properties, $\pi$N scattering and electromagnetic pion
production. These predictions have been shown to be consistent with QCD in the
meson sector by increasingly accurate lattice calculations. At present there is
good agreement between experiment and ChPT calculations, including the $\pi\pi$
and $\pi$N s wave scattering lengths and the $\pi^{0}$ lifetime. Recent,
accurate pionic atom data are in agreement with chiral calculations once
isospin breaking effects due to the mass difference of the up and down quarks
are taken into account, as was required to extract the $\pi\pi$ scattering
lengths. In addition to tests of the theory, comparisons between $\pi\pi$ and
$\pi$N interactions based on general chiral principles are discussed. Lattice
calculations are now providing results for the fundamental, long and
inconclusively studied, $\pi$N $\sigma$ term and the contribution of the
strange quark to the mass of the proton. Increasingly accurate experiments in
electromagnetic pion production experiments from the proton which test ChPT
calculations (and their energy region of validity) are presented. These
experiments are also beginning to measure the final state $\pi$N interaction.
This paper is based on the concluding remarks made at the Chiral Dynamics
Workshop CD12 held at Jefferson Lab in Aug. 2012.


title: Patterning droplets with durotaxis

abstract:
  Numerous cell-types have shown a remarkable ability to detect and move along
gradients in stiffness of an underlying substrate -- a process known as
durotaxis. The mechanisms underlying durotaxis are still unresolved, but
generally believed to involve active sensing and locomotion. Here, we show that
simple liquid droplets also undergo durotaxis. By modulating substrate
stiffness, we obtain fine control of droplet position on soft, flat substrates.
Unlike other control mechanisms, droplet durotaxis works without imposing
chemical, thermal, electrical or topographical gradients. This enables a new
approach to large-scale droplet patterning and is potentially useful for many
applications, such as microfluidics, thermal control and microfabrication.


title: Dendroidal weak 2-categories

abstract:
  We discuss the dendroidal notion of weak higher categories introduced by
Moerdijk and Weiss and we prove that dendroidal weak 2-categories are
equivalent to bicategories.


title: Silicon Detector Dark Matter Results from the Final Exposure of CDMS II

abstract:
  We report results of a search for Weakly Interacting Massive Particles
(WIMPS) with the silicon detectors of the CDMS II experiment. This blind
analysis of 140.2 kg-days of data taken between July 2007 and September 2008
revealed three WIMP-candidate events with a surface-event background estimate
of 0.41^{+0.20}_{-0.08}(stat.)^{+0.28}_{-0.24}(syst.). Other known backgrounds
from neutrons and 206Pb are limited to < 0.13 and <0.08 events at the 90%
confidence level, respectively. The exposure of this analysis is equivalent to
23.4 kg-days for a recoil energy range of 7-100 keV for a WIMP of mass 10
GeV/c2. The probability that the known backgrounds would produce three or more
events in the signal region is 5.4%. A profile likelihood ratio test of the
three events that includes the measured recoil energies gives a 0.19%
probability for the known-background-only hypothesis when tested against the
alternative WIMP+background hypothesis. The highest likelihood occurs for a
WIMP mass of 8.6 GeV/c2 and WIMP-nucleon cross section of 1.9e-41 cm2.

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


title: Navigability on Networks: A Graph Theoretic Perspective

abstract:
  Human navigation has been of interest to psychologists and cognitive
scientists since the past few decades. It was in the recent past that a study
of human navigational strategies was initiated with a network analytic
approach, instigated mainly by Milgrams small world experiment. We brief the
work in this direction and provide answers to the algorithmic questions raised
by the previous study. It is noted that humans have a tendency to navigate
using centers of the network - such paths are called the
center-strategic-paths. We show that the problem of finding a
center-strategic-path is an easy one. We provide a polynomial time algorithm to
find a center-strategic-path between a given pair of nodes. We apply our
finding in empirically checking the navigability on synthetic networks and
analyze few special types of graphs.


title:
Generalized unitarity and the worldsheet S matrix in AdS_n x S^n x
  M^(10-2n)

abstract:
  The integrability-based solution of string theories related to
AdS(n)/CFT(n-1) dualities relies on the worldsheet S matrix. Using generalized
unitarity we construct the terms with logarithmic dependence on external
momenta at one- and two-loop order in the worldsheet S matrix for strings in a
general integrable worldsheet theory. We also discuss aspects of calculations
at higher orders. The S-matrix elements are expressed as sums of integrals with
coefficients given in terms of tree-level worldsheet four-point scattering
amplitudes. One-loop rational functions, not determined by two-dimensional
unitarity cuts, are fixed by symmetry considerations. They play an important
role in the determination of the two-loop logarithmic contributions. We
illustrate the general analysis by computing the logarithmic terms in the one-
and two-loop four-particle S-matrix elements in the massive worldsheet sectors
of string theory in AdS_5 x S^5, AdS_4 x CP^3, AdS_3 x S^3 x S^3 x S^1 and
AdS_3 x S^3 x T^4. We explore the structure of the S matrices and provide
explicit evidence for the absence of higher-order logarithms and for the
exponentiation of the one-loop dressing phase.


title:
Greedy Approach for Subspace Clustering from Corrupted and Incomplete
  Data

abstract:
  We describe the Greedy Sparse Subspace Clustering (GSSC) algorithm providing
an efficient method for clustering data belonging to a few low-dimensional
linear or affine subspaces from incomplete corrupted and noisy data. We provide
numerical evidences that, even in the simplest implementation, the greedy
approach increases the subspace clustering capability of the existing
state-of-the art SSC algorithm significantly.


title:
KOI-142, the King of Transit Variations, is a Pair of Planets near the
  2:1 Resonance

abstract:
  The Transit Timing Variations (TTVs) can be used as a diagnostic of
gravitational interactions between planets in a multi-planet system. Many
Kepler Objects of Interest (KOIs) exhibit significant TTVs, but KOI-142.01
stands out among them with an unrivaled, 12-hour TTV amplitude. Here we report
a thorough analysis of KOI-142.01's transits. We discover periodic Transit
Duration Variations (TDVs) of KOI-142.01 that are nearly in phase with the
observed TTVs. We show that KOI-142.01's TTVs and TDVs uniquely detect a
non-transiting companion with a mass 0.7 that of Jupiter (KOI-142c).
KOI-142.01's mass inferred from the transit variations is consistent with the
measured transit depth, suggesting a Neptune class planet (KOI-142b). The
orbital period ratio P_c/P_b=2.03 indicates that the two planets are just wide
of the 2:1 resonance. The present dynamics of this system, characterized here
in detail, can be used to test various formation theories that have been
proposed to explain the near-resonant pairs of exoplanets.


title:
Levy distributions of the currents intensities in metal dielectric
  systems

abstract:
  Levy distributions are involved in many physical phenomenon. The purpose of
our study is to understand metal insulator transitions in composite systems
using the above distributions. The exact method (EM) based on the calculation
of Kirchhoff s equations solutions is used to compute currents intensities in
each network division. Currents intensities distributions are studies for
different widths of the system. We interpret these distributions in terms of
Levy s law. Keywords: Levy distribution, percolation, composite materials,
resistors network.


title: Cost-Effective Broadcast in Cellular Networks

abstract:
  In recent years, video-related services such as YouTube and Netflix have
generated huge amounts of traffic and the network neutrality debate has emerged
as a major issue. In this paper, we consider feasibility of using a hybrid of
unicast and broadcast in cellular networks for high-traffic services (e.g.,
video streaming), from the perspective of cost effectiveness. To reflect
spatial characteristics of base stations (BSs) and mobile users (MUs), we use
the stochastic geometry approach where BSs and MUs are modeled as independent
homogeneous Poisson point processes (PPPs). With these assumptions and results,
we show how to cope with the trade-off between broadcast and unicast for
providing the service with affordable cost levels and reduced network load.
Moreover, we propose the so called periodic broadcasting service, where popular
video contents are periodically broadcast over cellular networks. This service
will make a positive impact on the network neutrality debate by stimulating
cooperation between mobile network operators (MNOs) and content providers
(CPs).


title: (a,b)-rectangle patterns in permutations and words

abstract:
  In this paper, we introduce the notion of a $(a,b)$-rectangle pattern on
permutations that not only generalizes the notion of successive elements
(bonds) in permutations, but is also related to mesh patterns introduced
recently by Br\"and\'en and Claesson. We call the $(k,k)$-rectangle pattern the
$k$-box pattern. To provide an enumeration result on the maximum number of
occurrences of the 1-box pattern, we establish an enumerative result on
pattern-avoiding signed permutations.
  Further, we extend the notion of $(k,\ell)$-rectangle patterns to words and
binary matrices, and provide distribution of $(1,\ell)$-rectangle patterns on
words; explicit formulas are given for up to 7 letter alphabets where $\ell \in
\{1,2\}$, while obtaining distributions for larger alphabets depends on
inverting a matrix we provide. We also provide similar results for the
distribution of bonds over words. As a corollary to our studies we confirm a
conjecture of Mathar on the number of "stable LEGO walls" of width 7 as well as
prove three conjectures due to Hardin and a conjecture due to Barker. We also
enumerate two sequences published by Hardin in the On-Line Encyclopedia of
Integer Sequences.


title: Relativisation makes contradictions harder for Resolution

abstract:
  We provide a number of simplified and improved separations between pairs of
Resolution-with-bounded-conjunction refutation systems, Res(d), as well as
their tree-like versions, Res*(d). The contradictions we use are natural
combinatorial principles: the Least number principle, LNP_n and an ordered
variant thereof, the Induction principle, IP_n.
  LNP_n is known to be easy for Resolution. We prove that its relativisation is
hard for Resolution, and more generally, the relativisation of LNP_n iterated d
times provides a separation between Res(d) and Res(d+1). We prove the same
result for the iterated relativisation of IP_n, where the tree-like variant
Res*(d) is considered instead of Res(d).
  We go on to provide separations between the parameterized versions of Res(1)
and Res(2). Here we are able again to use the relativisation of the LNP_n, but
the classical proof breaks down and we are forced to use an alternative.
Finally, we separate the parameterized versions of Res*(1) and Res*(2). Here,
the relativisation of IP_n will not work as it is, and so we make a vectorising
amendment to it in order to address this shortcoming


title: Fourier coefficients of vector-valued modular forms of dimension 2

abstract:
  We prove the following theorem. Suppose that $F=(f_1, f_2)$ is a
2-dimensional vector-valued modular form on $SL_2(Z)$ whose component functions
$f_1, f_2$ have rational Fourier coefficients with bounded denominators. Then
$f_1$ and $f_2$ are classical modular forms on a congruence subgroup of the
modular group.


title:
Observation of Intense Second Harmonic Generation from MoS$_{2}$ Atomic
  Crystals

abstract:
  Since de discovery of graphene, the family of 2-dimensional materials has
attracted much recent attention. In this work, the nonlinear optical properties
of few-layer MoS2 two-dimensional crystals are studied using femtosecond laser
pulses. We observed highly efficient second harmonic generation from the
odd-layer crystals, which shows a polarization intensity dependence that
directly reveals the underlying symmetry and orientation of the crystal.
Additionally, the measured second-order susceptibility spectra provide
information about the electronic structure of the material. Our results open up
new opportunities for studying the non-linear optical properties in these novel
2D crystals.


title: Classes of complete intersection numerical semigroups

abstract:
  We consider several classes of complete intersection numerical semigroups,
aris- ing from many different contexts like algebraic geometry, commutative
algebra, coding theory and factorization theory. In particular, we determine
all the logical implications among these classes and provide examples. Most of
these classes are shown to be well-behaved with respect to the operation of
gluing.


title: Multidimensional Tauberian theorems for vector-valued distributions

abstract:
  We prove several Tauberian theorems for regularizing transforms of
vector-valued distributions. The regularizing transform of $f$ is given by the
integral transform $M^{f}_{\varphi}(x,y)=(f\ast\varphi_{y})(x),$
$(x,y)\in\mathbb{R}^{n}\times\mathbb{R}_{+}$, with kernel
$\varphi_{y}(t)=y^{-n}\varphi(t/y)$. We apply our results to the analysis of
asymptotic stability for a class of Cauchy problems, Tauberian theorems for the
Laplace transform, the comparison of quasiasymptotics in distribution spaces,
and we give a necessary and sufficient condition for the existence of the trace
of a distribution on $\left\{x_0\right\}\times \mathbb R^m$. In addition, we
present a new proof of Littlewood's Tauberian theorem.


title: Relative error due to a single bit-flip in floating-point arithmetic

abstract:
  We consider the error due to a single bit-flip in a floating point number. We
assume IEEE 754 double precision arithmetic, which encodes binary floating
point numbers in a 64-bit word. We assume that the bit-flip happens randomly so
it has equi-probability (1/64) to hit any of the 64 bits. Since we want to
mitigate the assumption on our initial floating-point number, we assume that it
is uniformly picked among all normalized number. With this framework, we can
summarize our findings as follows. The probability for a single bit flip to
cause a relative error less than 10^-11 in a normalized floating-point number
is above 25%; The probability for a single bit flip to cause a relative error
less than 10^-6 in a normalized floating-point number is above 50%; Etc.


title:
Extended duality relations between birth-death processes and partial
  differential equations

abstract:
  Duality relations between continuous-state and discrete-state stochastic
processes with continuous-time have already been studied and used in various
research fields. We propose extended duality relations, which enable us to
derive discrete-state stochastic processes from arbitrary diffusion-type
partial differential equations. The derivation is based on the Doi-Peliti
formalism and the algebraic probability theory, and it will be clarified that
additional states for the discrete-state stochastic processes must be
considered in some cases.


title: Torsion-free generalized connections and Heterotic Supergravity

abstract:
  This work revisits the notions of connection and curvature in generalized
geometry, with emphasis on torsion-free generalized connections on a transitive
Courant algebroid, compatible with a generalized metric. Non-exact Courant
algebroids have been considered recently by R. Rubio in the context of
$B_n$-generalised geometry and arise naturally from the theory of generalized
reduction of Burzstyn, Cavalcanti and Gualtieri. As an application, we provide
a mathematical derivation of the equations of motion of heterotic supergravity,
inspired by the work of Coimbra, Strickland-Constable and Waldram.


title: Boundary blow up under Sobolev mappings

abstract:
  We prove that for mappings $W^{1,n}(B^n, \R^n),$ continuous up to the
boundary, with modulus of continuity satisfying certain divergence condition,
the image of the boundary of the unit ball has zero $n$-Hausdorff measure. For
H\"older continuous mappings we also prove an essentially sharp generalized
Hausdorff dimension estimate.


title:
On a 1D transport equation with nonlocal velocity and supercritical
  dissipation

abstract:
  We study a 1D transport equation with nonlocal velocity. First, we prove
eventual regularization of the viscous regularization when dissipation is in
the supercritical range with non-negative initial data. Next, we will prove
global regularity for solutions when dissipation is slightly supercritical.
Both results utilize a nonlocal maximum principle.


title: Particles motion on topological Lifshitz black holes in 3+1 dimensions

abstract:
  In the present paper we study the causal structure of a topological black
hole presented by Mann R. B. JHEP 06, 075 (2009) by mean the standard
Lagrangian procedure, which allow us analyze qualitatively the behavior of test
particles using the effective potential. Then, the geodesic motion of massive
and massless particles is obtained analytically. We find that confined orbits
are forbidden on this spacetime, however radial photons can escape to infinity
in an infinite proper time but in a finite coordinate time, this correspond to
an interesting and novel result.


title:
On the $\mu$-invariant of the cyclotomic derivative of Katz p-adic
  L-function

abstract:
  When the branch character has root number -1, the corresponding
anticyclotomic Katz p-adic L-function identically vanishes. In this case, we
study the $\mu$-invariant of the cyclotomic derivative of Katz p-adic
L-function. As an application, this proves the non-vanishing of the
anticyclotomic regulator of a self-dual CM modular form with the root number
-1. The result also plays a crucial role in the recent work of Hsieh on the
Eisenstein ideal approach to a one-sided divisibility of the CM main
conjecture.


title:
Atom Based Vector Microwave Electrometry Using Rubidium Rydberg Atoms in
  a Vapor Cell

abstract:
  It is clearly important to pursue atomic standards for quantities like
electromagnetic fields, time, length and gravity. We have recently shown, using
Rydberg states, that Rb atoms in a vapor cell can serve as a practical, compact
standard for microwave electric field strength. Here, we demonstrate, for the
first time, that Rb atoms excited in a vapor cell can also be used for vector
microwave electrometry by using Rydberg atom electromagnetically induced
transparency. We describe the measurements necessary to obtain an arbitrary
microwave electric field polarization at a resolution of $0.5^\circ$. The
experiments are compared to theory and found to be in excellent agreement.


title:
Nonparametric Multivariate L1-median Regression Estimation with
  Functional Covariates

abstract:
  In this paper, a nonparametric estimator is proposed for estimating the
L1-median for multivariate conditional distribution when the covariates take
values in an infinite dimensional space. The multivariate case is more
appropriate to predict the components of a vector of random variables
simultaneously rather than predicting each of them separately. While estimating
the conditional L1-median function using the well-known Nadarya-Waston
estimator, we establish the strong consistency of this estimator as well as the
asymptotic normality. We also present some simulations and provide how to built
conditional con?fidence ellipsoids for the multivariate L1-median regression in
practice. Some numerical study in chemiometrical real data are carried out to
compare the multivariate L1-median regression with the vector of marginal
median regression when the covariate X is a curve as well as X is a random
vector.


title:
Waiting time distributions for the transport through a quantum dot
  tunnel coupled to one normal and one superconducting lead

abstract:
  We have studied the Waiting Time Distributions (WTDs) for sub-gap transport
through a single-level quantum dot tunnel coupled to one normal and one
superconducting lead. The WTDs reveal the internal dynamics of the system in
particular the coherent transfer of Cooper pairs between the dot and the
superconductor. The WTDs exhibit oscillations that can be directly associated
to the coherent oscillation between the empty and doubly occupied dot. The
oscillation frequency is equal to the energy splitting between the Andreev
bound states. These effects are more pronounced when the empty state and double
occupied state are in resonance.


title:
A Framework for Modelling Probabilistic Uncertainty in Rainfall Scenario
  Analysis

abstract:
  Predicting future probable values of model parameters, is an essential
pre-requisite for assessing model decision reliability in an uncertain
environment. Scenario Analysis is a methodology for modelling uncertainty in
water resources management modelling. Uncertainty if not considered
appropriately in decision making will decrease reliability of decisions,
especially in long-term planning. One of the challenges in Scenario Analysis is
how scenarios are made. One of the most approved methods is statistical
modelling based on Auto-Regressive models. Stream flow future scenarios in
developed basins that human has made changes to the natural flow process could
not be generated directly by ARMA modelling. In this case, making scenarios for
monthly rainfall and using it in a water resources system model makes more
sense. Rainfall is an ephemeral process which has zero values in some months
which introduces some limitations in making use of monthly ARMA model.
Therefore, a two stage modelling approach is adopted here which in the first
stage yearly modelling is done. Within this yearly model three ranges are
identified: Dry, Normal and Wet. In the normal range yearly ARMA modelling is
used. Dry and Wet range are considered as random processes and are modeled by
frequency analysis. Monthly distribution of rainfall, which is extracted from
available data from a moving average are considered to be deterministic and
fixed in time. Each rainfall scenario is composed of a yearly ARMA process
super-imposed by dry and wet events according to the frequency analysis. This
modelling framework is applied to available data from three rain-gauge stations
in Iran. Results show this modelling approach has better consistency with
observed data in comparison with making use of ARMA modelling alone.


title: Learning and Verifying Quantified Boolean Queries by Example

abstract:
  To help a user specify and verify quantified queries --- a class of database
queries known to be very challenging for all but the most expert users --- one
can question the user on whether certain data objects are answers or
non-answers to her intended query. In this paper, we analyze the number of
questions needed to learn or verify qhorn queries, a special class of Boolean
quantified queries whose underlying form is conjunctions of quantified Horn
expressions. We provide optimal polynomial-question and polynomial-time
learning and verification algorithms for two subclasses of the class qhorn with
upper constant limits on a query's causal density.


title:
Kernel-smoothed conditional quantiles of randomly censored functional
  stationary ergodic data

abstract:
  This paper, investigates the conditional quantile estimation of a scalar
random response and a functional random covariate (i.e. valued in some
infinite-dimensional space) whenever {\it functional stationary ergodic data
with random censorship} are considered. We introduce a kernel type estimator of
the conditional quantile function. We establish the strong consistency with
rate of this estimator as well as the asymptotic normality which induces a
confidence interval that is usable in practice since it does not depend on any
unknown quantity. An application to electricity peak demand interval prediction
with censored smart meter data is carried out to show the performance of the
proposed estimator.


title: Nonconforming finite element methods on quadrilateral meshes

abstract:
  It is well-known that it is comparatively difficult to design nonconforming
finite elements on quadrilateral meshes by using Gauss-Legendre points on each
edge of triangulations. One reason lies in that these degrees of freedom
associated to these Gauss-Legendre points are not all linearly independent for
usual expected polynomial spaces, which explains why only several lower order
nonconforming quadrilateral finite elements can be found in literature. The
present paper proposes two families of nonconforming finite elements of any odd
order and one family of nonconforming finite elements of any even order on
quadrilateral meshes. Degrees of freedom are given for these elements, which
are proved to be well-defined for their corresponding shape function spaces in
a unifying way. These elements generalize three lower order nonconforming
finite elements on quadrilaterals to any order. In addition, these
nonconforming finite element spaces are shown to be full spaces which is
somehow not discussed for nonconforming finite elements in literature before.


title:
Dependence of Substrate Irradiation Reaction Rate Stimulation on Lactic
  Dehydrogenase Source

abstract:
  Stimulation of LDH initial reaction rates by timed pre-irradiation of
crystalline sodium pyruvate and lithium lactate is reported for enzymes
isolated from rabbit muscle, pig heart, human erythrocytes and chicken heart.
The phenomenon investigated is referred to as the Comorosan effect. For the
mammalian source enzymes, the pyruvate irradiation stimulations occurred at
irradiation times of 5 and 35 sec. and the lactate irradiation times at 15 and
45 seconds. In contrast, for the chicken heart enzyme, the pyruvate irradiation
stimulations occurred at 15 and 35 sec., while those for lactate occurred at 5
and 20 sec. Thus, a shift in stimulatory irradiation times is found on going
from the mammalian enzymes to the avian enzyme. A similar shift between
mammalian and yeast enzymes has been established by Comorosan and co-workers.
For the chicken heart LDH, the separation between successive irradiation times
is different for the forward and reverse reactions. This is the first reported
incidence of the separation not being the same.


title: Hyperbolicity of the graph of non-separating multicurves

abstract:
  A non-separating multicurve of a surface S of genus g with m punctures is a
multicurve c so that S-c is connected. For k>0 define the graph of
non-separting k-multicurves to be the graph whose vertices are non-separating
multicurves with k components and where two such multicurves are connected by
an edge if they can be realized disjointly. We show that if k is smaller than
g/2+1 then this graph is hyperbolic.


title: Diffractive phenomena in high energy processes

abstract:
  We review the evolution of the studies of diffractive processes in the strong
interaction over the last 60 years. First, we briefly outline the early
developments of the theory based on analyticity and unitarity of the S-matrix,
including the derivation and exploration of the Regge trajectories and related
moving cuts. Special attention is paid to the concept of the Pomeron trajectory
introduced for description of total, elastic and diffractive cross sections at
high energies and to the emergence of the dynamics of multi-Pomeron
interactions.The role of large longitudinal distances and color coherent
phenomena for the understanding of inelastic diffraction in hadron-hadron
scattering and deep inelastic scattering is emphasized. The connection of these
phenomena to the cancellation of the contribution of the Glauber approximation
in hadron-nucleus collisions and to the understanding of the Gribov-Glauber
approximation is explained. The presence of different scales in perturbative
QCD due to masses of heavy quarks has led to the emergence of numerous new
phenomena including non-universality of the slopes of Regge trajectories made
of light and heavy quarks and non-universal energy dependence of elastic cross
sections. The application of the perturbative QCD techniques allowed us to
calculate from the first principles the interaction of small transverse size
color singlets with hadrons leading to the development of the quantitative
theory of hard exclusive reactions and to the successful prediction of many
regularities in hard large mass diffraction. It also led to the prediction of
the phenomenon of complete transparency of nuclear matter in QCD in special
processes. The conflict of perturbative QCD with probability conservation for
high energy processes of virtual photon-nucleon scattering is explained. Some
properties of the new QCD regime are outlined.


title: Closed expressions for averages of set partition statistics

abstract:
  In studying the enumerative theory of super characters' of the group of upper
triangular matrices over a finite field we found that the moments (mean,
variance and higher moments) of novel statistics on set partitions have simple
closed expressions as linear combinations of shifted bell numbers. It is shown
here that families of other statistics have similar moments. The coefficients
in the linear combinations are polynomials in $n$. This allows exact
enumeration of the moments for small $n$ to determine exact formulae for all
$n$.


title: Epidemic fronts in complex networks with metapopulation structure

abstract:
  Infection dynamics have been studied extensively on complex networks,
yielding insight into the effects of heterogeneity in contact patterns on
disease spread. Somewhat separately, metapopulations have provided a paradigm
for modeling systems with spatially extended and "patchy" organization. In this
paper we expand on the use of multitype networks for combining these paradigms,
such that simple contagion models can include complexity in the agent
interactions and multiscale structure. We first present a generalization of the
Volz-Miller mean-field approximation for Susceptible-Infected-Recovered (SIR)
dynamics on multitype networks. We then use this technique to study the special
case of epidemic fronts propagating on a one-dimensional lattice of
interconnected networks - representing a simple chain of coupled population
centers - as a necessary first step in understanding how macro-scale disease
spread depends on micro-scale topology. Using the formalism of front
propagation into unstable states, we derive the effective transport
coefficients of the linear spreading: asymptotic speed, characteristic
wavelength, and diffusion coefficient for the leading edge of the pulled
fronts, and analyze their dependence on the underlying graph structure. We also
derive the epidemic threshold for the system and study the front profile for
various network configurations. To our knowledge, this is the first such
application of front propagation concepts to random network models.


title: A Model for Scaling in Firms' Size and Growth Rate Distribution

abstract:
  We introduce a simple agent-based model which allows us to analyze three
stylized facts: a fat-tailed size distribution of companies, a `tent-shaped'
growth rate distribution, the scaling relation of the growth rate variance with
firm size, and the causality between them. This is achieved under the simple
hypothesis that firms compete for a scarce quantity (either aggregate demand or
workforce) which is allocated probabilistically. The model allows us to relate
size and growth rate distributions. We compare the results of our model to
simulations with other scaling relationships, and to similar models and relate
it to existing theory. Effects arising from binning data are discussed.


title:
Blue straggler evolution caught in the act in the Large Magellanic Cloud
  globular cluster Hodge 11

abstract:
  High-resolution {\sl Hubble Space Telescope} imaging observations show that
the radial distribution of the field-decontaminated sample of 162 'blue
straggler' stars (BSs) in the $11.7^{+0.2}_{-0.1}$ Gyr-old Large Magellanic
Cloud cluster Hodge 11 exhibits a clear bimodality. In combination with their
distinct loci in color--magnitude space, this offers new evidence in support of
theoretical expectations that suggest different BS formation channels as a
function of stellar density. In the cluster's color--magnitude diagram, the BSs
in the inner 15$"$ (roughly corresponding to the cluster's core radius) are
located more closely to the theoretical sequence resulting from stellar
collisions, while those in the periphery (at radii between 85$"$ and 100$"$)
are preferentially found in the region expected to contain objects formed
through binary mass transfer or coalescence. In addition, the objects'
distribution in color--magntiude space provides us with the rare opportunity in
an extragalactic environment to quantify the evolution of the cluster's
collisionally induced BS population and the likely period that has elapsed
since their formation epoch, which we estimate to have occurred $\sim$4--5 Gyr
ago.


title:
Graceful exit from inflation for minimally coupled Bianchi A scalar
  field models

abstract:
  We consider the dynamics of Bianchi A scalar field models which undergo
inflation. The main question is under which conditions does inflation come to
an end and is succeeded by a decelerated epoch. This so-called "graceful exit"
from inflation is an important ingredient in the standard model of cosmology,
but is, at this stage, only understood for restricted classes of solutions. We
present new results obtained by a combination of analytical and numerical
techniques.


title:
A Three-Charge-Coupled-Device Camera Based on Multiplexed Volume
  Hologram

abstract:
  We present a three-Charge-Coupled-Device (three-CCD) camera constructed upon
multiplexed volume holographic gratings. Three incoherent gratings are written
on the same holographic plate to guide the incident light into the three
monochromatic channels, where images of red, green and blue light are recorded
separately by CCD cameras. The reconstructed chromatic image from the
monochromatic images shows superior qualities over the images taken by a single
CCD camera.


title:
Spectrum of the Laplacian on a covering graph with pendant edges I: The
  one-dimensional lattice and beyond

abstract:
  In this paper, we examine covering graphs that are obtained from the
$d$-dimensional integer lattice by adding pendant edges. In the case of $d=1$,
we show that the Laplacian on the graph has a spectral gap and establish a
necessary and sufficient condition under which the Laplacian has no
eigenvalues. In the case of $d=2$, we show that there exists an arrangement of
the pendant edges such that the Laplacian has no spectral gap.


title:
Localization of Wiener Functionals of Fractional Regularity and
  Applications

abstract:
  In this paper we localize some of Watanabe's results on fractional Wiener
functionals, and use them to give a precise estimate of the difference between
two Donsker's delta functionals even with fractional differentiability. As an
application, the convergence rate of the density of the Euler scheme for
non-Markovian stochastic differential equations is obtained.


title:
On resolving singularities of piecewise-smooth discontinuous vector
  fields via small perturbations

abstract:
  A two-fold singularity is a point on a discontinuity surface of a
piecewise-smooth vector field at which the vector field is tangent to the
surface on both sides. Due to the double tangency, forward evolution from a
two-fold is typically ambiguous. This is an especially serious issue for
two-folds that are reached by the forward orbits of a non-zero measure set of
initial points. The purpose of this paper is to explore the concept of
perturbing the vector field so that forward evolution is well-defined, and
characterising the perturbed dynamics in the limit that the size of the
perturbation tends to zero. This concept is applied to a two-fold in two
dimensions. Three forms of perturbation: hysteresis, time-delay, and noise, are
analysed individually. In each case, the limit leads to a novel probabilistic
notion of forward evolution from the two-fold.


title:
Nuclear "pasta" structures in low-density nuclear matter and neutron
  star crust

abstract:
  In neutron star crust, non-uniform structure of nuclear matter is expected,
which is called the "pasta" structure. From the recent studies of giant flares
in magnetars, these structures might be related to some observables and
physical quantities of the neutron star crust. To investigate the above
quantities, we numerically explore the pasta structures with a fully
threedimensional geometry and study the properties of low-density nuclear
matter, based on the relativistic mean-field model and the Thomas-Fermi
approximation. We observe typical pasta structures for fixed proton
number-fraction and two of them for cold catalyzed matter. We also discuss the
crystalline configuration of "pasta".


title: New Actions for Modified Gravity and Supergravity

abstract:
  We extend the f(R) gravity action by including a generic dependence upon the
Weyl tensor, and further generalize it to supergravity by using the
super-curvature (R) and super-Weyl (W) chiral superfields in N=1 chiral curved
superspace. We argue that our (super)gravitational actions are the meaningful
extensions of the phenomenological f(R) gravity and its locally supersymmetric
generalization towards their UV completion and their embedding into superstring
theories. The proposed actions can be used for study of cosmological
perturbations and gravitational instabilities due to a nonvanishing Weyl tensor
in gravity and supergravity.


title:
An Algorithm for Computing Constrained Reflection Paths in Simple
  Polygon

abstract:
  Let $s$ be a source point and $t$ be a destination point inside an $n$-vertex
simple polygon $P$. Euclidean shortest paths and minimum-link paths between $s$
and $t$ inside $P$ have been well studied. Both these kinds of paths are simple
and piecewise-convex. However, computing optimal paths in the context of
diffuse or specular reflections does not seem to be an easy task. A path from a
light source $s$ to $t$ inside $P$ is called a diffuse reflection path if the
turning points of the path lie in the interiors of the boundary edges of $P$. A
diffuse reflection path is said to be optimal if it has the minimum number of
turning points amongst all diffuse reflection paths between $s$ and $t$. The
minimum diffuse reflection path may not be simple. The problem of computing the
minimum diffuse reflection path in low degree polynomial time has remained
open.
  In our quest for understanding the geometric structure of the minimum diffuse
reflection paths vis-a-vis shortest paths and minimum link paths, we define a
new kind of diffuse reflection path called a constrained diffuse reflection
path where (i) the path is simple, (ii) it intersects only the eaves of the
Euclidean shortest path between $s$ and $t$, and (iii) it intersects each eave
exactly once. For computing a minimum constrained diffuse reflection path from
$s$ to $t$, we present an $O(n(n+\beta))$ time algorithm, where $\beta =\Theta
(n^2)$ in the worst case. Here, $\beta$ depends on the shape of the polygon. We
also establish some properties relating minimum constrained diffuse reflection
paths and minimum diffuse reflection paths. Constrained diffuse reflection
paths introduced in this paper provide new geometric insights into the hitherto
unknown structures and shapes of optimal reflection paths.


title: Polar Codes: Speed of polarization and polynomial gap to capacity

abstract:
  We prove that, for all binary-input symmetric memoryless channels, polar
codes enable reliable communication at rates within $\epsilon > 0$ of the
Shannon capacity with a block length, construction complexity, and decoding
complexity all bounded by a {\em polynomial} in $1/\epsilon$. Polar coding
gives the {\em first known explicit construction} with rigorous proofs of all
these properties; previous constructions were not known to achieve capacity
with less than $\exp(1/\epsilon)$ decoding complexity except for erasure
channels.
  We establish the capacity-achieving property of polar codes via a direct
analysis of the underlying martingale of conditional entropies, without relying
on the martingale convergence theorem. This step gives rough polarization
(noise levels $\approx \epsilon$ for the "good" channels), which can then be
adequately amplified by tracking the decay of the channel Bhattacharyya
parameters. Our effective bounds imply that polar codes can have block length
(and encoding/decoding complexity) bounded by a polynomial in $1/\epsilon$. The
generator matrix of such polar codes can be constructed in polynomial time by
algorithmically computing an adequate approximation of the polarization
process.


title:
Non-abelian Self-Dual String and M2-M5 Branes Intersection in
  Supergravity

abstract:
  We consider the non-abelian theory (http://arxiv.org/abs/arXiv:1203.4224) for
an arbitrary number $N_5$ of five-branes and construct self-dual string
solution with an arbitrary $N_2$ unit of self-dual charges. This generalizes
the previous solution of non-abelian self-dual string
(http://arxiv.org/abs/arXiv:1207.1095) of $N_5=2, N_2=1$. The radius-transverse
distance relation describing the M2-branes spike, particularly its dependence
on $N_2$ and $N_5$, is obtained and is found to agree precisely with the
supergravity description of an intersecting M2-M5 branes system.


title: Ramsey spectroscopy with squeezed light

abstract:
  Traditional Ramsey spectroscopy has the frequency resolution $2\pi/T$, where
$T$ is the time separation between two light fields. Using squeezed states and
two-atom excitation joint detection, we present a new scheme achieving a higher
resolution $\pi/T$. We use two mode squeezed light which exhibits strong
entanglement.


title:
Popularity Prediction in Microblogging Network: A Case Study on Sina
  Weibo

abstract:
  Predicting the popularity of content is important for both the host and users
of social media sites. The challenge of this problem comes from the inequality
of the popularity of con- tent. Existing methods for popularity prediction are
mainly based on the quality of content, the interface of social media site to
highlight contents, and the collective behavior of user- s. However, little
attention is paid to the structural charac- teristics of the networks spanned
by early adopters, i.e., the users who view or forward the content in the early
stage of content dissemination. In this paper, taking the Sina Weibo as a case,
we empirically study whether structural character- istics can provide clues for
the popularity of short messages. We find that the popularity of content is
well reflected by the structural diversity of the early adopters. Experimental
results demonstrate that the prediction accuracy is signif- icantly improved by
incorporating the factor of structural diversity into existing methods.


title: Itinerant vs Localized Heavy-Electron Magnetism

abstract:
  It is demonstrated that itinerant-localized transition of heavy electrons
occurs inside the magnetically ordered phase of the Kondo-Heisenberg lattice.
The phase diagram and electronic structure are derived by means of the
continuous-time quantum Monte Carlo combined with the dynamical mean-field
theory. Around the itinerant-localized transition, nearly flat bands appear on
the Fermi surface with almost vanishing quasi-particle renormalization factor.
At the same time, there emerges a strong local magnetic fluctuation with a
minute energy scale. Considering both antiferromagnetic and ferromagnetic
Heisenberg interactions, coherent understanding is achieved on rich phase
diagrams observed in CeRh$_{1-x}$Co$_x$In$_5$, CeRu$_2$(Si$_x$Ge$_{1-x}$)$_2$,
UGe$_2$ and CeT$_2$Al$_{10}$ (T=Fe,Ru,Os).


title: Distributed Abstraction Algorithm for Online Predicate Detection

abstract:
  Analyzing a distributed computation is a hard problem in general due to the
combinatorial explosion in the size of the state-space with the number of
processes in the system. By abstracting the computation, unnecessary
explorations can be avoided. Computation slicing is an approach for abstracting
dis- tributed computations with respect to a given predicate. We focus on
regular predicates, a family of predicates that covers a large number of
commonly used predicates for runtime verification. The existing algorithms for
computation slicing are centralized in nature in which a single process is
responsible for computing the slice in either offline or online manner. In this
paper, we present a distributed online algorithm for computing the slice of a
distributed computation with respect to a regular predicate. Our algorithm
distributes the work and storage requirements across the system, thus reducing
the space and computation complexities per process. In addition, for
conjunctive predicates, our algorithm also reduces the message load per
process.