title:
Nonlinear Quantum Optomechanics via Individual Intrinsic Two-Level
  Defects

abstract:
  We propose to use the intrinsic two-level system (TLS) defect states found
naturally in integrated optomechanical devices for exploring cavity QED-like
phenomena with localized phonons. The Jaynes-Cummings-type interaction between
TLS and mechanics can reach the strong coupling regime for existing
nano-optomechanical systems, observable via clear signatures in the
optomechanical output spectrum. These signatures persist even at finite
temperature, and we derive an explicit expression for the temperature at which
they vanish. Further, the ability to drive the defect with a microwave field
allows for realization of phonon blockade, and the available controls are
sufficient to deterministically prepare non-classical states of the mechanical
resonator.


title: On De Graaf spaces of pseudoquotients

abstract:
  A space of pseudoquotients $\mathcal{B}(X,S)$ is defined as equivalence
classes of pairs $(x,f)$, where $x$ is an element of a non-empty set $X$, $f$
is an element of $S$, a commutative semigroup of injective maps from $X$ to
$X$, and $(x,f) \sim (y,g)$ if $gx=fy$. In this note we consider a
generalization of this construction where the assumption of commutativity of
$S$ by Ore type conditions. As in the commutative case, $X$ can be identified
with a subset of $\mathcal{B}(X,S)$ and $S$ can be extended to a group $G$ of
bijections on $\mathcal{B}(X,S)$. We introduce a natural topology on
$\mathcal{B}(X,S)$ and show that all elements of $G$ are homeomorphisms on
$\mathcal{B}(X,S)$.


title: Relaying Technologies for Smart Grid Communications

abstract:
  Wireless technologies can support a broad range of smart grid applications
including advanced metering infrastructure (AMI) and demand response (DR).
However, there are many formidable challenges when wireless technologies are
applied to the smart gird, e.g., the tradeoffs between wireless coverage and
capacity, the high reliability requirement for communication, and limited
spectral resources. Relaying has emerged as one of the most promising candidate
solutions for addressing these issues. In this article, an introduction to
various relaying strategies is presented, together with a discussion of how to
improve spectral efficiency and coverage in relay-based information and
communications technology (ICT) infrastructure for smart grid applications.
Special attention is paid to the use of unidirectional relaying, collaborative
beamforming, and bidirectional relaying strategies.


title:
Testing 24 micron and Infrared Luminosity as Star Formation Tracers for
  Galactic Star Forming Regions

abstract:
  We have tested some relations for star formation rates used in extra-galactic
studies for regions within the Galaxy. In nearby molecular clouds, where the
IMF is not fully-sampled, the dust emission at 24 micron greatly underestimates
star formation rates (by a factor of 100 on average) when compared to star
formation rates determined from counting YSOs. The total infrared emission does
no better. In contrast, the total far-infrared method agrees within a factor of
2 on average with star formation rates based on radio continuum emission for
massive, dense clumps that are forming enough massive stars to have the total
infrared luminosity exceed 10^4.5 Lsun. The total infrared and 24 micron also
agree well with each other for both nearby, low-mass star forming regions and
the massive, dense clumps regions.


title: The Relation Between Offset and Conchoid Constructions

abstract:
  The one-sided offset surface Fd of a given surface F is, roughly speaking,
obtained by shifting the tangent planes of F in direction of its oriented
normal vector. The conchoid surface Gd of a given surface G is roughly speaking
obtained by increasing the distance of G to a fixed reference point O by d.
Whereas the offset operation is well known and implemented in most CAD-software
systems, the conchoid operation is less known, although already mentioned by
the ancient Greeks, and recently studied by some authors. These two operations
are algebraic and create new objects from given input objects. There is a
surprisingly simple relation between the offset and the conchoid operation. As
derived there exists a rational bijective quadratic map which transforms a
given surface F and its offset surfaces Fd to a surface G and its conchoidal
surface Gd, and vice versa. Geometric properties of this map are studied and
illustrated at hand of some complete examples. Furthermore rational universal
parameterizations for offsets and conchoid surfaces are provided.


title: On cosmic hair and "de Sitter breaking" in linearized quantum gravity

abstract:
  We quantize linearized Einstein-Hilbert gravity on de Sitter backgrounds in a
covariant gauge. We verify the existence of a maximally-symmetric (i.e.de
Sitter-invariant) Hadamard state $\Omega$ for all globally hyperbolic de Sitter
backgrounds in all spacetime dimensions $D \ge 4$ by constructing the state's
2-point function in closed form. This 2-pt function is explicitly maximally
symmetric. We prove an analogue of the Reeh-Schlieder theorem for linearized
gravity. Using these results we prove a cosmic no-hair theorem for linearized
gravitons: for any state in the Hilbert space constructed from $\Omega$, the
late-time behavior of local observable correlation functions reduces to those
of $\Omega$ at an exponential rate with respect to proper time. We also provide
the explicitly maximally-symmetric graviton 2-pt functions in a class of
generalized de Donder gauges suitable for use in non-linear perturbation
theory. Along the way we clarify a few technical aspects which led previous
authors to conclude that these 2-pt functions do not exist.


title:
GPU-based Monte Carlo radiotherapy dose calculation using phase-space
  sources

abstract:
  A novel phase-space source implementation has been designed for GPU-based
Monte Carlo dose calculation engines. Due to the parallelized nature of GPU
hardware, it is essential to simultaneously transport particles of the same
type and similar energies but separated spatially to yield a high efficiency.
We present three methods for phase-space implementation that have been
integrated into the most recent version of the GPU-based Monte Carlo
radiotherapy dose calculation package gDPM v3.0. The first method is to
sequentially read particles from a patient-dependent phase-space and sort them
on-the-fly based on particle type and energy. The second method supplements
this with a simple secondary collimator model and fluence map implementation so
that patient-independent phase-space sources can be used. Finally, as the third
method (called the phase-space-let, or PSL, method) we introduce a novel
strategy to pre-process patient-independent phase-spaces and bin particles by
type, energy and position. Position bins located outside a rectangular region
of interest enclosing the treatment field are ignored, substantially decreasing
simulation time. The three methods were validated in absolute dose against
BEAMnrc/DOSXYZnrc and compared using gamma-index tests (2%/2mm above the 10%
isodose). It was found that the PSL method has the optimal balance between
accuracy and efficiency and thus is used as the default method in gDPM v3.0.
Using the PSL method, open fields of 4x4, 10x10 and 30x30 cm2 in water resulted
in gamma passing rates of 99.96%, 99.92% and 98.66%, respectively. Relative
output factors agreed within 1%. An IMRT patient plan using the PSL method
resulted in a passing rate of 97%, and was calculated in 50 seconds using a
single GPU compared to 8.4 hours (per CPU) for BEAMnrc/DOSXYZnrc.


title: Radiative Beta Decay for Studies of CP Violation

abstract:
  A triple-product correlation in the radiative \beta-decay rate of neutrons or
of nuclei, characterized by the kinematic variable \xi\equiv
(\vec{l}_\nu\times\vec{l}_e)\cdot\vec{k}, where, e.g., n(p) \to p(p') +
e^-(l_e) + \bar{\nu}_e(l_\nu) + \gamma(k), can be generated by the
pseudo-Chern-Simons term found by Harvey, Hill, and Hill as a consequence of
the baryon vector current anomaly and SU(2)_{L} x U(1)_Y gauge invariance at
low energies. The correlation probes the imaginary part of its coupling
constant, so that its observation at anticipated levels of sensitivity would
reflect the presence of sources of CP violation beyond the standard model. We
compute the size of the asymmetry in n\to p e^- \bar\nu_e \gamma decay in
chiral effective theory, compare it with the computed background from
standard-model final-state interactions, and consider the new physics scenarios
which would be limited by its experimental study.


title: Perspectives on Higgs Boson and Supersymmetry

abstract:
  We review the recent discovery of the Higgs like particle at $\sim 125$ GeV
and its implications for particle physics models. Specifically the implications
of the relatively high Higgs mass for the discovery of supersymmetry are
discussed. Several related topics such as naturalness and supersymmetry, dark
matter and unification are also discussed.


title: Quantum Information Science: Emerging No More

abstract:
  Short history of quantum information science. The chief message is that the
field is no longer emerging. It has arrived.


title:
New exponential, logarithm and q-probability in the non-extensive
  statistical physics

abstract:
  In this paper, a new exponential and logarithm related to the non-extensive
statistical physics is proposed by using the q-sum and q-product which satisfy
the distributivity. And we discuss the q-mapping from an ordinary probability
to q-probability. The q-entropy defined by the idea of q-probability is shown
to be q-additive.


title: Dynamics of scalar perturbations in f(R,T) gravity

abstract:
  In the context of f(R,T) theories of gravity, we study the evolution of
scalar cosmological perturbations in the metric formalism. According to
restrictions on the background evolution, a specific model within these
theories is assumed in order to guarantee the standard continuity equation.
Using a completely general procedure, we find the complete set of differential
equations for the matter density perturbations. In the case of sub-Hubble
modes, the density contrast evolution reduces to a second-order equation. We
show that for well-motivated f(R,T) Lagrangians the quasistatic approximation
yields to very different results from the ones derived in the frame of the
concordance {\Lambda}CDM model constraining severely the viability of such
theories.


title: Simulations of the non-linear thin shell instability

abstract:
  We use three-dimensional smoothed particle hydrodynamics simulations to study
the non-linear thin shell instability (NTSI) in supersonic colliding flows. We
show that for flows with monochromatic perturbations and for flows with
white-noise perturbations, growth speeds approximate quite well to the analytic
predictions of Vishniac (1994).
  For flows with subsonic turbulence, growth speeds match Vishniac's
predictions only at short wavelengths where the turbulence is weaker. We find
that supersonic turbulence, of a lower Mach number than the colliding flows,
completely suppresses the NTSI. Our results provide a diagnostic for
identifying the presence of the NTSI in colliding flows with turbulence.


title: Seeking Inflation Fossils in the Cosmic Microwave Background

abstract:
  If during inflation the inflaton couples to a "fossil" field, some new
scalar, vector, or tensor field, it typically induces a scalar-scalar-fossil
bispectrum. Even if the fossil field leaves no direct physical trace after
inflation, it gives rise to correlations between different Fourier modes of the
curvature or, equivalently, a nonzero curvature trispectrum, but without a
curvature bispectrum. Here we quantify the effects of a fossil field on the
cosmic microwave background (CMB) temperature fluctuations in terms of bipolar
spherical harmonics (BiPoSHs). The effects of vector and tensor fossils can be
distinguished geometrically from those of scalars through the parity of the
BiPoSHs they induce. However, the two-dimensional nature of the CMB sky does
not allow vectors to be distinguished geometrically from tensors. We estimate
the detectability of a signal in terms of the scalar-scalar-fossil coupling for
scalar, vector, and tensor fossils, assuming a local-type coupling. We comment
on a divergence that arises in the quadrupolar BiPoSH from the
scalar-scalar-tensor correlation in single-field slow-roll inflation.


title: A universal fermionic analogue of the shear viscosity

abstract:
  We holographically compute supercharge diffusion constants in supersymmetric
field theories, dual to AdS black brane solutions of arbitrary dimension. This
includes the extension of earlier work by Kontoudi and Policastro for D3-branes
to M2- and M5-brane theories. We consider the case of vanishing chemical
potential. In particular, we relate the product of a diffusion constant and the
energy density to a universal result for the fermionic absorption cross
section. This relation is analogous to the famous proof of universality of
$\eta / s$. We calculate the diffusion constants in two different ways: First,
the computation is performed via the low frequency, low momentum pole of the
correlator of supersymmetry currents. This pole describes the hydrodynamic
phonino mode, the massless Goldstone fermion of spontaneous supersymmetry
breaking by temperature. Second, the calculation is carried out using the dual
transversal mode of the bulk gravitino, with the help of a new Kubo formula.
Moreover, we provide some evidence for the applicability of generalized
dimensional reduction for fermions when computing the corresponding D$p$-brane
diffusion constants.


title: Learning How to Count: A High Multiplicity Search for the LHC

abstract:
  We introduce a search technique that is sensitive to a broad class of signals
with large final state multiplicities. Events are clustered into large radius
jets and jet substructure techniques are used to count the number of subjets
within each jet. The search consists of a cut on the total number of subjets in
the event as well as the summed jet mass and missing energy. Two different
techniques for counting subjets are described and expected sensitivities are
presented for eight benchmark signals. These signals exhibit diverse
phenomenology, including 2-step cascade decays, direct three body decays, and
multi-top final states. We find improved sensitivity to these signals as
compared to previous high multiplicity searches as well as a reduced reliance
on missing energy requirements. One benefit of this approach is that it allows
for natural data driven estimates of the QCD background.


title:
Supermassive Black Hole Binary Evolution in Axisymmetric Galaxies: the
  final parsec problem is not a problem

abstract:
  During a galaxy merger, the supermassive black hole (SMBH) in each galaxy is
thought to sink to the center of the potential and form a supermassive black
hole binary; this binary can eject stars via 3-body scattering, bringing the
SMBHs ever closer. In a static spherical galaxy model, the binary stalls at a
separation of about a parsec after ejecting all the stars in its loss cone --
this is the well-known final parsec problem. Earlier work has shown that the
centrophilic orbits in triaxial galaxy models are key in refilling the loss
cone at a high enough rate to prevent the black holes from stalling. However,
the evolution of binary SMBHs has never been explored in axisymmetric galaxies,
so it is not clear if the final parsec problem persists in these systems. Here
we use a suite of direct N-body simulations to follow SMBH binary evolution in
galaxy models with a range of ellipticity. For the first time, we show that
mere axisymmetry can solve the final parsec problem; we find the the SMBH
evolution is independent of N for an axis ratio of c/a=0.8, and that the SMBH
binary separation reaches the gravitational radiation regime for c/a=0.75.


title: Improving Electro-Weak Fits with TeV-scale Sterile Neutrinos

abstract:
  We study the impact of TeV-scale sterile neutrinos on electro-weak precision
observables and lepton number and flavour violating decays in the framework of
a type-I see-saw extension of the Standard Model. At tree level sterile
neutrinos manifest themselves via non-unitarity of the PMNS matrix and at
one-loop level they modify the oblique radiative corrections. We derive
explicit formulae for the S,T,U parameters in terms of the neutrino masses and
mixings and perform a numerical fit to the electro-weak observables. We find
regions of parameter space with a sizable active-sterile mixing which provide a
better over-all fit compared to the case where the mixing is negligible.
Specifically we find improvements of the invisible Z-decay width, the
charged-to-neutral-current ratio for neutrino scattering experiments and of the
deviation of the W boson mass from the theoretical expectation.


title:
Digging supplementary buried channels: investigating the notch
  architecture within the CCD pixels on ESA's Gaia satellite

abstract:
  The European Space Agency (ESA) Gaia satellite has 106 CCD image sensors
which will suffer from increased charge transfer inefficiency (CTI) as a result
of radiation damage. To aid the mitigation at low signal levels, the CCD design
includes Supplementary Buried Channels (SBCs, otherwise known as `notches')
within each CCD column. We present the largest published sample of Gaia CCD SBC
Full Well Capacity (FWC) laboratory measurements and simulations based on 13
devices. We find that Gaia CCDs manufactured post-2004 have SBCs with FWCs in
the upper half of each CCD that are systematically smaller by two orders of
magnitude (<50 electrons) compared to those manufactured pre-2004 (thousands of
electrons). Gaia's faint star (13 < G < 20 mag) astrometric performance
predictions by Prod'homme et al. and Holl et al. use pre-2004 SBC FWCs as
inputs to their simulations. However, all the CCDs already integrated onto the
satellite for the 2013 launch are post-2004. SBC FWC measurements are not
available for one of our five post-2004 CCDs but the fact it meets Gaia's image
location requirements suggests it has SBC FWCs similar to pre-2004. It is too
late to measure the SBC FWCs onboard the satellite and it is not possible to
theoretically predict them. Gaia's faint star astrometric performance
predictions depend on knowledge of the onboard SBC FWCs but as these are
currently unavailable, it is not known how representative of the whole focal
plane the current predictions are. Therefore, we suggest Gaia's initial
in-orbit calibrations should include measurement of the onboard SBC FWCs. We
present a potential method to do this. Faint star astrometric performance
predictions based on onboard SBC FWCs at the start of the mission would allow
satellite operating conditions or CTI software mitigation to be further
optimised to improve the scientific return of Gaia.


title:
Interaction-driven transition between topological states in a Kondo
  insulator

abstract:
  Heavy fermion materials naturally combine strong spin-orbit interactions and
electronic correlations. When there is precisely one conduction electron per
impurity spin, the coherent heavy fermion state is insulating. This Kondo
insulating state has recently been argued to belong to the class of quantum
spin Hall states. Motivated by this conjecture and a very recent experimental
realization of this state, we investigate a model for Kondo insulators with
spin-orbit coupling. Using DMFT, we observe an interaction-driven transition
between two distinct topological states, indicated by a closing of the bulk gap
and a simultaneous change of the Z2 topological invariant. At large interaction
strength we find a topological heavy fermion state, characterized by strongly
renormalized heavy bulk bands, hosting a pair of zero-energy edge modes. The
model allows a detailed understanding of the temperature dependence of the
single particle spectral function and in particular the energy scales at which
one observes the appearance of edge states within the bulk gap.


title:
A New Timescale for Period Change in the Pulsating DA White Dwarf WD
  0111+0018

abstract:
  We report the most rapid rate of period change measured to date for a
pulsating DA (hydrogen atmosphere) white dwarf (WD), observed in the 292.9 s
mode of WD 0111+0018. The observed period change, faster than 10^{-12} s/s,
exceeds by more than two orders of magnitude the expected rate from cooling
alone for this class of slow and simply evolving pulsating WDs. This result
indicates the presence of an additional timescale for period evolution in these
pulsating objects. We also measure the rates of period change of nonlinear
combination frequencies and show that they share the evolutionary
characteristics of their parent modes, confirming that these combination
frequencies are not independent modes but rather artifacts of some nonlinear
distortion in the outer layers of the star.


title:
BUDHIES I: characterizing the environments in and around two clusters at
  z~0.2

abstract:
  We present the optical spectroscopy for the Blind Ultra Deep HI Environmental
Survey (BUDHIES). With the Westerbork Synthesis Radio Telescope, BUDHIES has
detected HI in over 150 galaxies in and around two Abell clusters at z~0.2.
With the aim of characterizing the environments of the HI-detected galaxies, we
obtained multi-fiber spectroscopy with the William Herschel Telescope. In this
paper, we describe the spectroscopic observations, report redshifts and EW[OII]
measurements for ~600 galaxies, and perform an environmental analysis. In
particular, we present cluster velocity dispersion measurements for 5 clusters
and groups in the BUDHIES volume, as well as a detailed substructure analysis.


title:
Observation and Spectroscopy of a Two-Electron Wigner Molecule in an
  Ultra-Clean Carbon Nanotube

abstract:
  Coulomb interactions can have a decisive effect on the ground state of
electronic systems. The simplest system in which interactions can play an
interesting role is that of two electrons on a string. In the presence of
strong interactions the two electrons are predicted to form a Wigner molecule,
separating to the ends of the string due to their mutual repulsion. This
spatial structure is believed to be clearly imprinted on the energy spectrum,
yet to date a direct measurement of such a spectrum in a controllable
one-dimensional setting is still missing. Here we use an ultra-clean suspended
carbon nanotube to realize this system in a tunable potential. Using tunneling
spectroscopy we measure the excitation spectra of two interacting carriers,
electrons or holes, and identify seven low-energy states characterized by their
spin and isospin quantum numbers. These states fall into two multiplets
according to their exchange symmetries. The formation of a strongly-interacting
Wigner molecule is evident from the small energy splitting measured between the
two multiplets, that is quenched by an order of magnitude compared to the
non-interacting value. Our ability to tune the two-electron state in space and
to study it for both electrons and holes provides an unambiguous demonstration
of the fundamental Wigner molecule state.


title:
Renormalization of Entanglement Entropy and the Gravitational Effective
  Action

abstract:
  The entanglement entropy associated with a spatial boundary in quantum field
theory is UV divergent, with the leading term proportional to the area of the
boundary. For a class of quantum states defined by a path integral, the
Callan-Wilczek formula gives a geometrical definition of the entanglement
entropy. We show that, for this class of quantum states, the entanglement
entropy is rendered UV-finite by precisely the counterterms required to cancel
the UV divergences in the gravitational effective action. In particular, the
leading contribution to the entanglement entropy is given by the renormalized
Bekenstein-Hawking formula, in accordance with a proposal of Susskind and
Uglum. We show that the subleading UV-divergent terms in the entanglement
entropy depend nontrivially on the quantum state. We compute new subleading
terms in the entanglement entropy and find agreement with the Wald entropy
formula for black hole spacetimes with bifurcate Killing horizons. We speculate
that the entanglement entropy of an arbitrary spatial boundary may be a
well-defined observable in quantum gravity.


title:
The Comparative Chemical Evolution of an Isolated Dwarf Galaxy: A VLT
  and Keck Spectroscopic Survey of WLM

abstract:
  Building on our previous spectroscopic and photometric analysis of the
isolated Local Group dwarf irregular (dIrr) galaxy WLM, we present a comparison
of the metallicities of its RGB stars with respect to the well studied Local
Group dwarf spheroidal galaxies (dSphs) and Magellanic Clouds. We calculate a
mean metallicity of [Fe/H]$ = -1.28 \pm 0.02$, and intrinsic spread in
metallicity of $\sigma = 0.38 \pm 0.04$ dex, similar to the mean and spread
observed in the massive dSph Fornax and the Small Magellanic Cloud. Thus,
despite its isolated environment the global metallicity still follows
expectations for WLM's mass and its global chemical evolution is similar to
other nearby luminous dwarf galaxies (gas-rich or gas-poor). The data also show
a radial gradient in [Fe/H] of $\rm{d[Fe/H]/dr_{c}} = -0.04 \pm 0.04$ dex
$\rm{r_{c}^{-1}}$, which is flatter than that seen in the unbiased and
spatially extended surveys of dSphs. Comparison of the spatial distribution of
[Fe/H] in WLM, the Magellanic Clouds, and a sample of Local Group dSphs, shows
an apparent dichotomy in the sense that the dIrrs have statistically flatter
radial [Fe/H] gradients than the low angular momentum dSphs. The correlation
between angular momentum and radial metallicity gradient is further supported
when considering the Local Group dEs. This chemodynamic relationship offers a
new and useful constraint for environment driven dwarf galaxy evolution models
in the Local Group.


title: Finite temperature R-squared quantum gravity

abstract:
  The quantum gravity path integral's measure can be written as the product of
classical backgrounds and quantum fluctuations about each background. After
proving that fluctuations about the background do not diffuse in Hilbert space
and obey the laws of many-body statistics, their probability distributions,
entropy, and expected background are determined. This background obeys
expectation-valued Einstein equations and features an entropy-based positive
cosmological constant. From the fluctuation probability distributions, a finite
temperature, R-squared, quantum gravity path integral is constructed whose
action presents an interaction picture of quantum gravity that `moves with' the
expected background in Hilbert space. Within this interaction picture of
quantum fluctuations about an expected background, the fields required to
describe quantum gravity have been transformed into `ordinary' quantum fields
propagating on this `rigid' or `fixed' expected background. Back-reaction has
been fully accounted for, and the quantum formulation is manifestly background
independent.


title:
Wigner time-delay distribution in chaotic cavities and freezing
  transition

abstract:
  Using the joint distribution for proper time-delays of a chaotic cavity
derived by Brouwer, Frahm & Beenakker [Phys. Rev. Lett. {\bf 78}, 4737 (1997)],
we obtain, in the limit of large number of channels $N$, the large deviation
function for the distribution of the Wigner time-delay (the sum of proper
times) by a Coulomb gas method. We show that the existence of a power law tail
originates from narrow resonance contributions, related to a (second order)
freezing transition in the Coulomb gas.


title: Acceleration detection of large (probably) prime numbers

abstract:
  In order to avoid unnecessary applications of Miller-Rabin algorithm to the
number in question, we resort to trial division by a few initial prime numbers,
since such a division take less time.
  How far we should go with such a division is the that we are trying to answer
in this paper?For the theory of the matter is fully resolved. However, that in
practice we do not have much use.
  Therefore, we present a solution that is probably irrelevant to theorists,
but it is very useful to people who have spent many nights to produce large
(probably) prime numbers using its own software.


title: Mesh patterns with superfluous mesh

abstract:
  Mesh patterns are a generalization of classical permutation patterns that
encompass classical, bivincular, Bruhat-restricted patterns, and some barred
patterns. In this paper, we describe all mesh patterns whose avoidance is
coincident with classical avoidance, in a sense declaring that the additional
data of a mesh was unnecessary for these patterns. We also describe the
permutations having the fewest superfluous meshes, and the permutations having
the most, enumerating the superfluous meshes in each case.


abstract:
  Simulating from a gamma distribution with small shape parameter is a
challenging problem. Towards an efficient method, we obtain a limiting
distribution for a suitably normalized gamma distribution when the shape
parameter tends to zero. Then this limiting distribution provides insight to
the construction of a new, simple, and highly efficient acceptance--rejection
algorithm. Comparisons based on acceptance rates show that the proposed
procedure is more efficient than existing acceptance--rejection methods.


title:
Reflection and refraction in Robert Grosseteste's De Lineis, Angulis et
  Figuris

abstract:
  In his scientific treatise entitled De Lineis, Angulis et Figuris, seu
Fractionibus et Reflexionibus Radiorum, Robert Grosseteste is discussing some
qualitative geometric rules about reflection and refraction. However, he is
also discussing about the power of reflected and refracted light. The reading
of these discussions is quite interesting, and what Grosseteste is telling
seems well-posed, when compared with the Fresnel reflectance.


title: Collective Motion of Moshers at Heavy Metal Concerts

abstract:
  Human collective behavior can vary from calm to panicked depending on social
context. Using videos publicly available online, we study the highly energized
collective motion of attendees at heavy metal concerts. We find these extreme
social gatherings generate similarly extreme behaviors: a disordered gas-like
state called a mosh pit and an ordered vortex-like state called a circle pit.
Both phenomena are reproduced in flocking simulations demonstrating that human
collective behavior is consistent with the predictions of simplified models.


title: CMB Tensor Anisotropies in f(R) Gravity

abstract:
  The cosmic microwave background (CMB) carries information from the last
scattering surface that puts constraints on the multitude of proposed
cosmological models and the gravitation theories they are based on. One class
of such theories is $f(R)$ gravity, which has become an interesting endeavour
to correct for the degeneracies of the concordance model.
  We presents a description of CMB anisotropies generated by tensor
perturbations in $f(R)$ theories of gravity. The temperature and the $E$-mode
polarisation power spectra in the special case of $f(R)=R^n$ are computed using
a modified version of CAMB package.


title: Compatibility of Kisin modules for different uniformizers

abstract:
  Let p be a prime and T a lattice inside a semi-stable representation V. We
prove that Kisin modules associated to T by selecting different uniformizers
are isomorphic after tensoring a subring in W(R). As consequences, we show that
several lattices inside the filtered (phi, N)-module of V constructed from
Kisin modules are independent on the choice of uniformizers. Finally we use a
similar strategy to show that the Wach module can be recovered from the
(\varphi, \hat G)-module associated to T when V is crystalline and the base
field is unramified.


title:
Strange Quark PDF Uncertainty and its Implications for W/Z Production at
  the LHC

abstract:
  We investigate the impact of parton distribution functions (PDFs)
uncertainties on W/Z production at the LHC, concentrating on the strange quark
PDF. Additionally we examine the extent to which precise measurements at the
LHC can provide additional information on the proton flavor structure.


title:
Thermal Conductivity and Phonon Transport in Suspended Few-Layer
  Hexagonal Boron Nitride

abstract:
  The thermal conductivity of suspended few-layer hexagonal boron nitride
(h-BN) was measured using a micro-bridge device with built-in resistance
thermometers. Based on the measured thermal resistance values of 11-12 atomic
layer h-BN samples with suspended length ranging between 3 and 7.5 um, the
room-temperature thermal conductivity of a 11-layer sample was found to be
about 360 Wm-1K-1, approaching the basal plane value reported for bulk h-BN.
The presence of a polymer residue layer on the sample surface was found to
decrease the thermal conductivity of a 5-layer h-BN sample to be about 250
Wm-1K-1 at 300 K. Thermal conductivities for both the 5 layer and the 11 layer
samples are suppressed at low temperatures, suggesting increasing scattering of
low frequency phonons in thin h-BN samples by polymer residue.


title: The LHCb experiment: status and recent results

abstract:
  The LHCb experiment is one of the major research projects at the Large Hadron
Collider. Its acceptance and instrumentation is optimised to perform
high-precision studies of flavour physics and particle production in a unique
kinematic range at unprecedented collision energies. Using large data samples
accumulated in the years 2010-2012, the LHCb collaboration has conducted a
series of measurements providing a sensitive test of the Standard Model and
strengthening our knowledge of flavour physics, QCD and electroweak processes.
The status of the experiment and some of its recent results are presented here.


title: Formation of giant planets and brown dwarfs on wide orbits

abstract:
  Context: We studied numerically the formation of giant planet (GP) and brown
dwarf (BD) embryos in gravitationally unstable protostellar disks and compared
our findings with directly-imaged, wide-orbit (>= 50 AU) companions known
to-date. The viability of the disk fragmentation scenario for the formation of
wide-orbit companions in protostellar disks around (sub-)solar mass stars was
investigated. Methods: We used numerical hydrodynamics simulations of disk
formation and evolution with an accurate treatment of disk thermodynamics. The
use of the thin-disk limit allowed us to probe the long-term evolution of
protostellar disks. We focused on models that produced wide-orbit GP/BD
embryos, which opened a gap in the disk and showed radial migration timescales
similar to or longer than the typical disk lifetime. Results: While disk
fragmentation was seen in the majority of our models, only 6 models out of 60
revealed the formation of quasi-stable, wide-orbit GP/BD embryos. Disk
fragmentation produced GP/BD embryos with masses in the 3.5-43 M_J range,
covering the whole mass spectrum of directly-imaged, wide-orbit companions to
(sub-)solar mass stars. On the other hand, our modelling failed to produce
embryos on orbital distances <= 170 AU, whereas several directly-imaged
companions were found at smaller orbits down to a few AU. Disk fragmentation
also failed to produce wide-orbit companions around stars with mass <= 0.7
Msun, in disagreement with observations. Conclusions: Disk fragmentation is
unlikely to explain the whole observed spectrum of wide-orbit companions to
(sub-)solar-mass stars and other formation mechanisms, e.g., dynamical
scattering of closely-packed companions onto wide orbits, should be invoked to
account for companions at orbital distance from a few tens to \approx 150 AU
and wide-orbit companions with masses of the host star <= 0.7 Msun. (abridged)


title: Scalar-tensor gravitation and the Bakry-Emery-Ricci tensor

abstract:
  The Bakry-Emery generalized Ricci tensor arises in scalar-tensor gravitation
theories in the conformal gauge known as the Jordan frame. Recent results from
the mathematics literature show that standard singularity and splitting
theorems that hold when an energy condition is applied in general relativity
also hold when that energy condition is applied to the Bakry-Emery tensor. We
show here that a direct consequence is that the Hawking-Penrose singularity
theorem and the timelike splitting theorem hold for scalar-tensor theory in the
Jordan frame. As examples, we consider dilaton gravity (including totally
anti-symmetric torsion) and the Brans-Dicke family of scalar-tensor theories.
For Brans-Dicke theory the theorems do not extend to cover the entire space of
values of the Brans-Dicke family parameter omega, and so may fail to hold for
omega<-1. Observations show that this range of values does not describe our
Universe, but the result is in accord with examples in the literature of
Brans-Dicke spacetimes that have no singularity in the Jordan frame and do not
split as a Riemannian product.


title:
Finite-size scaling investigation of the liquid-liquid critical point in
  ST2 water and its stability with respect to crystallization

abstract:
  The liquid-liquid critical point scenario of water hypothesizes the existence
of two metastable liquid phases---low-density liquid (LDL) and high-density
liquid (HDL)---deep within the supercooled region. The hypothesis originates
from computer simulations of the ST2 water model, but the stability of the LDL
phase with respect to the crystal is still being debated. We simulate
supercooled ST2 water at constant pressure, constant temperature and constant
number of molecules N for N<=729 and times up to 1000 ns. We observe clear
differences between the two liquids, both structural and dynamical. Using
several methods, including finite-size scaling, we confirm the presence of a
liquid-liquid phase transition ending in a critical point. We find that the LDL
is stable with respect to the crystal in 98% of our runs (we perform 372 runs
for LDL or LDL-like states), and in 100% of our runs for the two largest system
sizes (N=512 and 729, for which we perform 136 runs for LDL or LDL-like
states). In all these runs tiny crystallites grow and then melt within 1000 ns.
Only for N<=343 we observe six events (over 236 runs for LDL or LDL-like
states) of spontaneous crystallization after crystallites reach an estimated
critical size of about 70+/-10 molecules.


title:
Connectivity of the Icosahedral Network and a Dramatically Growing
  Static Length Scale in Cu-Zr Binary Metallic Glasses

abstract:
  We report on and characterize, via molecular dynamics (MD) studies, the
evolution of the structure of Cu50Zr50 and Cu64Zr36 metallic glasses (MGs) as
temperature is varied. Interestingly, a percolating icosahedral network appears
in the Cu64Zr36 system as it is supercooled. This leads us to introduce a
static length scale, which grows dramatically as this three dimensional system
approaches the glass transition. Amidst interpenetrating connections,
non-interpenetrating connections between icosahedra are shown to become
prevalent upon supercooling and to greatly enhance the connectivity of the MG's
icosahedral network. Additionally, we characterize the chemical compositions of
the icosahedral networks and their components. These findings demonstrate the
importance of non-interpenetrating connections for facilitating extensive
structural networks in Cu-Zr MGs, which in turn drive dynamical slowing in
these materials.


title:
Status of Leading-Order Hadronic Vacuum Polarization Dispersion
  Calculation

abstract:
  The leading-order hadronic contribution to the muon magnetic anomaly a_{\mu}
= (g_{\mu} - 2)/2, calculated using a dispersion integral of e+e- annihilation
data and tau decay data, is briefly reviewed. This contribution has the largest
uncertainty to the predicted value of a_{\mu}, which differs from the
experimental value by ~3.6 (2.4) standard deviations for the e+e- (tau) based
analysis. New results since the last workshop and main open issues on the
subject are discussed.


title: Pulsar scintillations from corrugated reconnection sheets in the ISM

abstract:
  We show that surface waves along interstellar current sheets closely aligned
with the line of sight lead to pulsar scintillation properties consistent with
those observed. This mechanism naturally produces the length and density scales
of the ISM scattering lenses that are required to explain the magnitude and
dynamical spectrum of the scintillations. In this picture, the parts of warm
ionized interstellar medium that are responsible for the scintillations are
relatively quiescent, with scintillation and scattering resulting from weak
waves propagating along magnetic domain boundary current sheets, which are both
expected from helicity conservation and have been observed in numerical
simulations. The model statistically predicts the spacing and amplitudes of
inverted parabolic arcs seen in Fourier-transformed dynamical spectra of
strongly scintillating pulsars with only 3 parameters. Multi-frequency,
multi-epoch low frequency VLBI observations can quantitatively test this
picture. If successful, in addition to mapping the ISM, this may open the door
to precise nanoarcsecond pulsar astrometry, distance measurements, and emission
studies using these 10AU interferometers in the sky.


title: New measurement and QCD analysis of DIS data from HERA

abstract:
  This talk covers three contributions from H1: "Measurement of the inclusive
e^\pm p scattering cross section at high inelasticity y and of the structure
function F_L", "Determination of the integrated luminosity at HERA using
elastic QED Compton events" and "Inclusive deep inelastic scattering at high Q2
with longitudinally polarized lepton beams at HERA". These are new measurements
mainly based on the full HREA-II data but include also those from HERA-I in the
combination whenever it is relevant. The main results of these measurements are
briefly summarized here.


title: Variability of Hypervelocity Stars

abstract:
  We present time-series photometry of 11 hypervelocity stars (HVSs) to
constrain their nature. Known HVSs are mostly late-B spectral type objects that
may be either main-sequence (MS) or evolved blue horizontal branch (BHB) stars.
Fortunately, MS stars at these effective temperatures, $T_{eff} \sim$ 12,000 K,
are good candidates for being a class of variable stars known as slowly
pulsating B stars (SPBs). We obtained photometry on four nights at the WIYN 3.5
m telescope, and on six nights on the 2.4 m Hiltner telescope. Using sinusoidal
fits, we constrain four of our targets to have periods between $P \sim 0.2 - 2$
days, with a mean value of 0.6 days. Our amplitudes vary between $A = 0.5 -
3$%. This suggests that these four HVSs are SPBs. We discuss a possible origin
for these stars, and why further observations are necessary.


title: Generalized Thue-Morse Continued Fractions

abstract:
  The Thue-Morse sequence is generalized to the $TM_m$ sequences and two
equivalent definitions are given. This generalization leads to transcendental
numbers and has Queff\'elec's theorem on Thue-Morse continued fractions as a
special case. It is also shown that the theorem of Adamczewski and Bugeaud for
palindromic continued fractions cannot be applied in this case.


title:
Relational Access Control with Bivalent Permissions in a Social
  Web/Collaboration Architecture

abstract:
  We describe an access control model that has been implemented in the web
content management framework "Deme" (which rhymes with "team"). Access control
in Deme is an example of what we call "bivalent relation object access
control"(BROAC). This model builds on recent work by Giunchiglia et al. on
relation-based access control (RelBAC), as well as other work on relational,
flexible, fine-grained, and XML access control models. We describe Deme's
architecture and review access control models, motivating our approach. BROAC
allows for both positive and negative permissions, which may conflict with each
other. We argue for the usefulness of defining access control rules as objects
in the target database, and for the necessity of resolving permission conflicts
in a social Web/collaboration architecture. After describing how Deme access
control works, including the precedence relations between different permission
types in Deme, we provide several examples of realistic scenarios in which
permission conflicts arise, and show how Deme resolves them. Initial
performance tests indicate that permission checking scales linearly in time on
a practical Deme website.


title:
Practical Analysis of Codebook Design and Frequency Offset Estimation
  for Virtual-MIMO Systems

abstract:
  A virtual multiple-input multiple-output (MIMO) wireless system using the
receiver-side cooperation with the compress-and-forward (CF) protocol, is an
alternative to a point-to-point MIMO system, when a single receiver is not
equipped with multiple antennas. It is evident that the practicality of CF
cooperation will be greatly enhanced if an efficient source coding technique
can be used at the relay. It is even more desirable that CF cooperation should
not be unduly sensitive to carrier frequency offsets (CFOs). This paper
presents a practical study of these two issues. Firstly, codebook designs of
the Voronoi vector quantization (VQ) and the tree-structure vector quantization
(TSVQ) to enable CF cooperation at the relay are described. A comparison in
terms of the codebook design and encoding complexity is analyzed. It is shown
that the TSVQ is much simpler to design and operate, and can achieve a
favorable performance-complexity tradeoff. Furthermore, this paper demonstrates
that CFO can lead to significant performance degradation for the virtual MIMO
system. To overcome this, it is proposed to maintain clock synchronization and
jointly estimate the CFO between the relay and the destination. This approach
is shown to provide a significant performance improvement.


title:
An Efficient Approximation to the Likelihood for Gravitational Wave
  Stochastic Background Detection Using Pulsar Timing Data

abstract:
  Direct detection of gravitational waves by pulsar timing arrays will become
feasible over the next few years. In the low frequency regime ($10^{-7}$ Hz --
$10^{-9}$ Hz), we expect that a superposition of gravitational waves from many
sources will manifest itself as an isotropic stochastic gravitational wave
background. Currently, a number of techniques exist to detect such a signal;
however, many detection methods are computationally challenging. Here we
introduce an approximation to the full likelihood function for a pulsar timing
array that results in computational savings proportional to the square of the
number of pulsars in the array. Through a series of simulations we show that
the approximate likelihood function reproduces results obtained from the full
likelihood function. We further show, both analytically and through
simulations, that, on average, this approximate likelihood function gives
unbiased parameter estimates for astrophysically realistic stochastic
background amplitudes.


title:
A Unified Approach to Integration and Optimization of Parametric
  Ordinary Differential Equations

abstract:
  Parameter estimation in ordinary differential equations, although applied and
refined in various fields of the quantitative sciences, is still confronted
with a variety of difficulties. One major challenge is finding the global
optimum of a log-likelihood function that has several local optima, e.g. in
oscillatory systems. In this publication, we introduce a formulation based on
continuation of the log-likelihood function that allows to restate the
parameter estimation problem as a boundary value problem. By construction, the
ordinary differential equations are solved and the parameters are estimated
both in one step. The formulation as a boundary value problem enables an
optimal transfer of information given by the measurement time courses to the
solution of the estimation problem, thus favoring convergence to the global
optimum. This is demonstrated explicitly for the fully as well as the partially
observed Lotka-Volterra system.


title:
The catalogue of radial velocity standard stars for Gaia I. Pre-launch
  release

abstract:
  The Radial Velocity Spectrograph (RVS) on board of Gaia needs to be
calibrated using stable reference stars known in advance. The catalogue
presented here has being built for that purpose. It includes 1420 radial
velocity standard star candidates selected on strict criteria in order to
fulfill the Gaia-RVS requirements. A large programme of ground based
observations is underway since 2006 to monitor these stars and verify their
stability which has to be better than 300 m/s over several years. The
observations have been made on the echelle spectrographs ELODIE and SOPHIE on
the 1.93-m telescope at Observatoire de Haute-Provence (OHP), NARVAL on the
Telescope Bernard Lyot at Observatoire du Pic du Midi and CORALIE on the
Euler-Swiss Telescope at La Silla. Data from the OHP and Geneva Observatory
archives have also been retrieved as well as HARPS spectra from the ESO
archive. We provide for each star a mean radial velocity in the SOPHIE scale,
derived from the combination of velocities measured with those instruments,
after having carefully estimated their differences of zero-points. In total
10214 radial velocity measurements have been obtained for the 1420 stars. With
a mean time baseline of 6.35 years, 92.9% of the candidates fulfill a target
stability criterion of 300 m/s. 343 stars are found to be constant at the level
of 100 m/s over 10 years. Comparisons with the catalogues of Nidever et
al.(2002) and Chubak et al.(2012) show an excellent agreement for FGK stars,
with zero-point differences lower than 100 m/s and a remarkably low RMS scatter
of 33 m/s in the case of Nidever et al.(2002), suggesting that the precision of
the catalogue presented here is better than this value. This catalog will
likely be useful for other large-scale spectroscopic surveys such as APOGEE,
Gaia-ESO, HERMES and LAMOST.


title: Propagators in Polymer Quantum Mechanics

abstract:
  Polymer Quantum Mechanics is based on some of the techniques used in the loop
quantization of gravity that are adapted to describe systems possessing a
finite number of degrees of freedom. It has been used in two ways: on one hand
it has been used to represent some aspects of the loop quantization in a
simpler context, and, on the other, it has been applied to each of the infinite
mechanical modes of other systems. Indeed, this polymer approach was recently
implemented for the free scalar field propagator. In this work we compute the
polymer propagators of the free particle and a particle in a box; amusingly,
just as in the non polymeric case, the one of the particle in a box may be
computed also from that of the free particle using the method of images. We
verify the propagators hereby obtained satisfy standard properties such as:
consistency with initial conditions, composition and Green's function
character. Furthermore they are also shown to reduce to the usual Schr\"odinger
propagators in the limit of small parameter $\mu_0$, the length scale
introduced in the polymer dynamics and which plays a role analog of that of
Planck length in Quantum Gravity.


title: e+e- results from BABAR and implications for g-2

abstract:
  The BABAR collaboration has nearly completed a program of precise
measurements of the cross sections for the dominant channels of e+e- -->
hadrons from threshold to an energy of 3-5 GeV using the initial-state
radiation (ISR) method, i.e. the measurement of the cross sections e+e- -->
gamma hadrons with the energetic photon detected at large angle to the beams.
These data are used as input to vacuum polarization dispersion integrals, in
particular the hadronic contribution to the muon g-2 anomaly. In addition to
the recently measured pi+pi- cross section, giving the dominant contibution,
many multihadronic channels have been investigated, with some recent examples
presented here. We give preliminary results for the process e+e- -->
K+K-(gamma) using 232 fb-1 of data collected with the BABAR detector at e+e-
center-of-mass energies near 10.6 GeV. The lowest-order contribution to the
hadronic vacuum polarization term in the muon magnetic anomaly is obtained for
this channel: amu-KK-LO=(22.95 +-0.14(stat) +-0.22(syst)) 10^-10, which is
about a factor of three more precise than the previous world average value.


title: Phase diagram of the quantum O(2)-model in 2+1 dimensions

abstract:
  The quantum O(2) model in 2+1 dimensions is studied by simulating the 3d O(2)
model near criticality. Finite densities are introduced by a non-zero chemical
potential mu, and the worm algorithm is used to circumvent the sign problem.
The renormalisation is discussed in some detail. We find that the onset value
of the chemical potential coincides with the mass gap. The mu-dependence of the
density rules out Bose-Einstein condensation and might be compatible with an
interacting Fermi gas. The mu-T phase diagram is explored using the density and
the magnetic susceptibility. In the cold, but dense regime of the phase
diagram, we find a superfluid phase.


title:
Noise reduction by coupling of stochastic processes and canalization in
  biology

abstract:
  Randomness is an unavoidable feature of the intracellular environment due to
chemical reactants being present in low copy number. That phenomenon, predicted
by Delbr\"uck long ago \cite{delbruck40}, has been detected in both prokaryotic
\cite{elowitz02,cai06} and eukaryotic \cite{blake03} cells after the
development of the fluorescence techniques. On the other hand, developing
organisms, e.g. {\em D. melanogaster}, exhibit strikingly precise
spatio-temporal patterns of protein/mRNA concentrations
\cite{gregor07b,manu09a,manu09b,boettiger09}. Those two characteristics of
living organisms are in apparent contradiction: the precise patterns of protein
concentrations are the result of multiple mutually interacting random chemical
reactions. The main question is to establish biochemical mechanisms for
coupling random reactions so that canalization, or fluctuations reduction
instead of amplification, takes place. Here we explore a model for coupling two
stochastic processes where the noise of the combined process can be smaller
than that of the isolated ones. Such a canalization occurs if, and only if,
there is negative covariance between the random variables of the model. Our
results are obtained in the framework of a master equation for a negatively
self-regulated -- or externally regulated -- binary gene and show that the
precise control due to negative self regulation \cite{becskei00} is because it
may generate negative covariance. Our results suggest that negative covariance,
in the coupling of random chemical reactions, is a theoretical mechanism
underlying the precision of developmental processes.


title:
Symmetric (2,3,5) distributions, an interesting ODE of 7th order and
  Plebanski metric

abstract:
  We show that the unique 7th order ODE having 10 contact symmetries appears
naturally in the theory of generic 2-distributions in dimension five.


title:
Correcting beliefs in the mean-field and Bethe approximations using
  linear response

abstract:
  Approximating marginals of a graphical model is one of the fundamental
problems in the theory of networks. In a recent paper a method was shown to
construct a variational free energy such that the linear response estimates,
and maximum entropy estimates (for beliefs) are in agreement, with implications
for direct and inverse Ising problems[1]. In this paper we demonstrate an
extension of that method, incorporating new information from the response
matrix, and we recover the adaptive-TAP equations as the first order
approximation[2]. The method is flexible with respect to applications of the
cluster variational method, special cases of this method include Naive Mean
Field (NMF) and Bethe. We demonstrate that the new framework improves
estimation of marginals by orders of magnitude over standard implementations in
the weak coupling limit. Beyond the weakly coupled regime we show there is an
improvement in a model where the NMF and Bethe approximations are known to be
poor for reasons of frustration and short loops.


title: Testing and Evaluation of Service Oriented Systems

abstract:
  Evaluation of service oriented system has been a challenge, though there are
large number of evaluation metrics exist but none of them is efficient to
evaluate these systems effectively.This paper discusses the different testing
tools and evaluation methods available for SOA and summarizes their limitation
and support in context of service oriented architectures.


title:
On Randomized Sensing and Access Schemes in Wireless Ad-Hoc Cognitive
  Networks

abstract:
  Over the past decade we have witnessed a rapid growth and development in
wireless communication systems, to the point that conventional spectrum
allocation policies may not be able to fulfill them all. Federal Communications
Commission (FCC) licenses certain frequency segments to a particular user in a
particular geographic area. Industrial, Scientific and Medical (ISM) radio
bands have also been envisioned for all other unlicensed user to share, as long
as they follow certain power regulations. But with the recent boom in the
wireless technologies, these open channels have become overcrowded with
everything from wireless networks to wireless controllers.
  Therefore, the regulatory and standardization agencies have been working on
new spectrum regulation policies for wireless communication systems. The
underlying idea is to let unlicensed users to use the licensed band as long as
they can guarantee low interference to the licensed users. Though seemingly
simple, sophisticated interference management protocols are needed to meet the
expected level of transparency accepted by licensed users. In this report we
adopt the dynamic spectrum access approach to limit the interference to primary
users and analyze the performance of the cognitive MAC protocols based on
randomized sensing and access schemes.


title: Spontaneous synchrony in power-grid networks

abstract:
  An imperative condition for the functioning of a power-grid network is that
its power generators remain synchronized. Disturbances can prompt
desynchronization, which is a process that has been involved in large power
outages. Here we derive a condition under which the desired synchronous state
of a power grid is stable, and use this condition to identify tunable
parameters of the generators that are determinants of spontaneous
synchronization. Our analysis gives rise to an approach to specify parameter
assignments that can enhance synchronization of any given network, which we
demonstrate for a selection of both test systems and real power grids. Because
our results concern spontaneous synchronization, they are relevant both for
reducing dependence on conventional control devices, thus offering an
additional layer of protection given that most power outages involve equipment
or operational errors, and for contributing to the development of "smart grids"
that can recover from failures in real time.


title:
Gamma Rays from Cosmic-Ray Proton Scattering in AGN Jets: the
  Intra-Cluster Gas vastly outshines Dark Matter

abstract:
  Active Galactic Nuclei (AGN) host powerful jets containing high-energy
electrons and protons. The astrophysical environment where AGNs and their jets
are found is characterized by large concentrations of both dark matter (DM) and
intra-cluster medium (ICM) gas. As the high-energy jet particles transverse the
DM and the ICM, elastic and inelastic scattering processes generically lead to
the production of final-state photons. As first envisioned by Bloom and Wells
(1998), and as more recently pointed out by us and others, the scattering of
electrons off of DM could lead to a potentially detectable gamma-ray signal,
with the parton-level contribution from protons offering dimmer perspectives.
Recently, Chang et al. argued that taking into account photons from
hadronization and showering, the actual photon flux is substantially increased.
Here, we point out that the proton-jets have to be highly collimated, contrary
to what predicted by simple blob-geometry jet-models sometimes employed in
these studies, otherwise they would produce a very large flux of photons from
inelastic collisions with ICM nucleons, which would outshine by many orders of
magnitude the signal from DM, for almost any reasonable ICM and DM density
profiles.


title: Estimation of Distribution Overlap of Urn Models

abstract:
  A classical problem in statistics is estimating the expected coverage of a
sample, which has had applications in gene expression, microbial ecology,
optimization, and even numismatics. Here we consider a related extension of
this problem to random samples of two discrete distributions. Specifically, we
estimate what we call the dissimilarity probability of a sample, i.e., the
probability of a draw from one distribution not being observed in k draws from
another distribution. We show our estimator of dissimilarity to be a
U-statistic and a uniformly minimum variance unbiased estimator of
dissimilarity over the largest appropriate range of k. Furthermore, despite the
non-Markovian nature of our estimator when applied sequentially over k, we show
it converges uniformly in probability to the dissimilarity parameter, and we
present criteria when it is approximately normally distributed and admits a
consistent jackknife estimator of its variance. As proof of concept, we analyze
V35 16S rRNA data to discern between various microbial environments. Other
potential applications concern any situation where dissimilarity of two
discrete distributions may be of interest. For instance, in SELEX experiments,
each urn could represent a random RNA pool and each draw a possible solution to
a particular binding site problem over that pool. The dissimilarity of these
pools is then related to the probability of finding binding site solutions in
one pool that are absent in the other.


title: Dark Matter Subhalos and the X-ray Morphology of the Coma Cluster

abstract:
  Structure formation models predict that clusters of galaxies contain numerous
massive subhalos. The gravity of a subhalo in a cluster compresses the
surrounding intracluster gas and enhances its X-ray emission. We present a
simple model, which treats subhalos as slow moving and gasless, for computing
this effect. Recent weak lensing measurements by Okabe et al. have determined
masses of ~ 10^13 solar masses for three mass concentrations projected within
300 kpc of the center of the Coma Cluster, two of which are centered on the
giant elliptical galaxies NGC 4889 and NGC 4874. Adopting a smooth spheroidal
beta-model for the gas distribution in the unperturbed cluster, we model the
effect of these subhalos on the X-ray morphology of the Coma Cluster, comparing
our results to Chandra and XMM-Newton X-ray data. The agreement between the
models and the X-ray morphology of the central Coma Cluster is striking. With
subhalo parameters from the lensing measurements, the distances of the three
subhalos from the Coma Cluster midplane along our line of sight are all tightly
constrained. Using the model to fit the subhalo masses for NGC 4889 and NGC
4874 gives 9.1 x 10^12 and 7.6 x 10^12 solar masses, respectively, in good
agreement with the lensing masses. These results lend strong support to the
argument that NGC 4889 and NGC 4874 are each associated with a subhalo that
resides near the center of the Coma Cluster. In addition to constraining the
masses and 3-d location of subhalos, the X-ray data show promise as a means of
probing the structure of central subhalos.


title: Isolated and Binary Neutron Stars in Dynamical Chern-Simons Gravity

abstract:
  We study isolated and binary neutron stars in dynamical Chern-Simons gravity.
This theory modifies the Einstein-Hilbert action through the introduction of a
dynamical scalar field coupled to the Pontryagin density. We here treat this
theory as an effective model, working to leading order in the Chern-Simons
coupling. We first construct isolated neutron star solutions in the
slow-rotation expansion to quadratic order in spin. We find that isolated
neutron stars acquire a scalar dipole charge that corrects its spin angular
momentum to linear order in spin and corrects its mass and quadrupole moment to
quadratic order in spin, as measured by an observer at spatial infinity. We
then consider neutron stars binaries that are widely separated and solve for
their orbital evolution in this modified theory. We find that the evolution of
post-Keplerian parameters is modified, with the rate of periastron advance
being the dominant correction at first post-Newtonian order. We conclude by
applying these results to observed pulsars with the aim to place constraints on
dynamical Chern-Simons gravity. We find that the modifications to the observed
mass are degenerate with the neutron star equation of state, which prevents us
from testing the theory with the inferred mass of the millisecond pulsar
J1614-2230. We also find that the corrections to the post-Keplerian parameters
are too small to be observable today even with data from the double binary
pulsar J0737-3039. Our results suggest that pulsar observations are not
currently capable of constraining dynamical Chern-Simons gravity, and thus,
gravitational-wave observations may be the only path to a stringent constraint
of this theory in the imminent future.


title: Normal numbers and normality measure

abstract:
  The normality measure $\mathcal{N}$ has been introduced by Mauduit and
S{\'a}rk{\"o}zy in order to describe the pseudorandomness properties of finite
binary sequences. Alon, Kohayakawa, Mauduit, Moreira and R{\"o}dl proved that
the minimal possible value of the normality measure of an $N$-element binary
sequence satisfies $$ (1/2 + o(1)) \log_2 N \leq \min_{E_N \in \{0,1\}^N}
\mathcal{N}(E_N) \leq 3 N^{1/3} (\log N)^{2/3} $$ for sufficiently large $N$.
In the present paper we improve the upper bound to $c (\log N)^2$ for some
constant $c$, by this means solving the problem of the asymptotic order of the
minimal value of the normality measure up to a logarithmic factor, and
disproving a conjecture of Alon \emph{et al.}. The proof is based on relating
the normality measure of binary sequences to the discrepancy of normal numbers
in base 2.


abstract:
  In this paper, we present an automated technique SWATI: Synthesizing
Wordlengths Automatically Using Testing and Induction, which uses a combination
of Nelder-Mead optimization based testing, and induction from examples to
automatically synthesize optimal fixedpoint implementation of numerical
routines. The design of numerical software is commonly done using
floating-point arithmetic in design-environments such as Matlab. However, these
designs are often implemented using fixed-point arithmetic for speed and
efficiency reasons especially in embedded systems. The fixed-point
implementation reduces implementation cost, provides better performance, and
reduces power consumption. The conversion from floating-point designs to
fixed-point code is subject to two opposing constraints: (i) the word-width of
fixed-point types must be minimized, and (ii) the outputs of the fixed-point
program must be accurate. In this paper, we propose a new solution to this
problem. Our technique takes the floating-point program, specified accuracy and
an implementation cost model and provides the fixed-point program with
specified accuracy and optimal implementation cost. We demonstrate the
effectiveness of our approach on a set of examples from the domain of automated
control, robotics and digital signal processing.


title:
Improving Quality of Service and Reducing Power Consumption with WAN
  accelerator in Cloud Computing Environments

abstract:
  The widespread use of cloud computing services is expected to deteriorate a
Quality of Service and toincrease the power consumption of ICT devices, since
the distance to a server becomes longer than before. Migration of virtual
machines over a wide area can solve many problems such as load balancing and
power saving in cloud computing environments.
  This paper proposes to dynamically apply WAN accelerator within the network
when a virtual machine is moved to a distant center, in order to prevent the
degradation in performance after live migration of virtual machines over a wide
area. mSCTP-based data transfer using different TCP connections before and
after migration is proposed in order to use a currently available WAN
accelerator. This paper does not consider the performance degradation of live
migration itself. Then, this paper proposes to reduce the power consumption of
ICT devices, which consists of installing WAN accelerators as part of cloud
resources actively and increasing the packet transfer rate of communication
link temporarily. It is demonstrated that the power consumption with WAN
accelerator could be reduced to one-tenth of that without WAN accelerator.


title: Adelic divisors on arithmetic varieties

abstract:
  In this article, we generalize several fundamental results for arithmetic
divisors, such as the continuity of the volume function, the generalized Hodge
index theorem, Fujita's approximation theorem for arithmetic divisors and
Zariski decompositions for arithmetic divisors on arithmetic surfaces, to the
case of the adelic arithmetic divisors.


title: Update XML Views

abstract:
  View update is the problem of translating an update to a view to some updates
to the source data of the view. In this paper, we show the factors determining
XML view update translation, propose a translation procedure, and propose
translated updates to the source document for different types of views. We
further show that the translated updates are precise. The proposed solution
makes it possible for users who do not have access privileges to the source
data to update the source data via a view.


title:
Macroscopic Quantum Mechanics: Theory and Experimental Concepts of
  Optomechanics

abstract:
  Rapid experimental progress has recently allowed the use of light to prepare
macroscopic mechanical objects into nearly pure quantum states. This research
field of quantum optomechanics opens new doors toward testing quantum
mechanics, and possibly other laws of physics, in new regimes. In the first
part of this paper, I will review a set of techniques of quantum measurement
theory that are often used to analyze quantum optomechanical systems. Some of
these techniques were originally designed to analyze how a classical driving
force passes through a quantum system, and can eventually be detected with
optimal signal-to-noise ratio --- while others focus more on the quantum state
evolution of a mechanical object under continuous monitoring. In the second
part of this paper, I will review a set of experimental concepts that will
demonstrate quantum mechanical behavior of macroscopic objects --- quantum
entanglement, quantum teleportation, and the quantum Zeno effect. Taking the
interplay between gravity and quantum mechanics as an example, I will review a
set of speculations on how quantum mechanics can be modified for macroscopic
objects, and how these speculations --- and their generalizations --- might be
tested by optomechanics.


title:
Time in the theory of relativity: on natural clocks, proper time, the
  clock hypothesis, and all that

abstract:
  When addressing the notion of proper time in the theory of relativity, it is
usually taken for granted that the time read by an accelerated clock is given
by the Minkowski proper time. However, there are authors like Harvey Brown that
consider necessary an extra assumption to arrive at this result, the so-called
clock hypothesis. In opposition to Brown, Richard T. W. Arthur takes the clock
hypothesis to be already implicit in the theory. In this paper I will present a
view different from these authors by recovering Einstein's notion of natural
clock and showing its relevance to the debate.


title:
Time-dependent density-functional studies on strength functions in
  neutron-rich nuclei

abstract:
  The electric dipole (E1) strength functions have been systematically
calculated based on the time-dependent density functional theory (TDDFT), using
the finite amplitude method and the real-time approach to the TDDFT with
pairing correlations. The low-energy E1 strengths in neutron-rich isotopes show
peculiar behaviors, such as sudden enhancement and reduction, as functions of
the neutron numbers.They seem to be due to the interplay between the neutron
shell effect and the deformation effect.


title:
Solutions to the ultradiscrete KdV equation expressed as the maximum of
  a quadratic function

abstract:
  We propose the functions defined by the maximum of a discrete quadratic form
and satisfying the ultradiscrete KdV equation. These functions includes not
only soliton solutions but also pseudo-periodic solutions. In the proof, we
employ some facts of discrete convex analysis.


title: High density matter

abstract:
  The microscopic composition and properties of matter at super-saturation
densities have been the subject of intense investigation for decades. The
scarcity of experimental and observational data has lead to the necessary
reliance on theoretical models. However, there remains great uncertainty in
these models, which, of necessity, have to go beyond the over-simple assumption
that high density matter consists only of nucleons and leptons. Heavy strange
baryons, mesons and quark matter in different forms and phases have to be
included to fulfil basic requirements of fundamental laws of physics. In this
review the latest developments in construction of the Equation of State (EoS)
of high-density matter at zero and finite temperature assuming different
composition of the matter are surveyed. Critical comparison of model EoS with
available observational data on neutron stars, including gravitational masses,
radii and cooling patterns is presented. The effect of changing rotational
frequency on the composition of neutron stars during their lifetime is
demonstrated. Compatibility of EoS of high-density, low temperature compact
objects and low density, high temperature matter created in heavy-ion
collisions is discussed.


title: ZL-amenability constants of finite groups with two character degrees

abstract:
  We calculate the exact amenability constant of the centre of $\ell^1(G)$ when
$G$ is one of the following classes of finite group: dihedral; extraspecial; or
Frobenius with abelian complement and kernel. This is done using a formula
which applies to all finite groups with two character degrees. In passing, we
answer in the negative a question raised in work of the third author with
Azimifard and Spronk (J. Funct. Anal. 2009).


title: Linear Approximation of Rear Stagnation-point Flow

abstract:
  This paper investigates the nature of the development of two-dimensional
steady flow of an incompressible fluid at the rear stagnation-point.


title: Coding for Combined Block-Symbol Error Correction

abstract:
  We design low-complexity error correction coding schemes for channels that
introduce different types of errors and erasures: on the one hand, the proposed
schemes can successfully deal with symbol errors and erasures, and, on the
other hand, they can also successfully handle phased burst errors and erasures.


title:
Generalized Counting Constraint Satisfaction Problems With Determinantal
  Circuits

abstract:
  Generalized counting constraint satisfaction problems include Holant problems
with planarity restrictions; polynomial-time algorithms for such problems
include matchgates and matchcircuits, which are based on Pfaffians. In
particular, they use gates which are expressible in terms of a vector of
sub-Pfaffians of a skew-symmetric matrix. We introduce a new type of circuit
based instead on determinants, with seemingly different expressive power. In
these determinantal circuits, a gate is represented by the vector of all minors
of an arbitrary matrix. Determinantal circuits permit a different class of
gates. Applications of these circuits include proofs of theorems from algebraic
graph theory including the Chung-Langlands formula for the number of rooted
spanning forests of a graph and computing Tutte Polynomials of certain
matroids. They also give a strategy for simulating quantum circuits with closed
timelike curves. Monoidal category theory provides a useful language for
discussing such counting problems, turning combinatorial restrictions into
categorical properties. We introduce the counting problem in monoidal
categories and count-preserving functors as a way to study FP subclasses of
problems in settings which are generally #P-hard. Using this machinery we show
that, surprisingly, determinantal circuits can be simulated by Pfaffian
circuits at quadratic cost.


title:
Self-Consistent Measurement and State Tomography of an Exchange-Only
  Spin Qubit

abstract:
  We report initialization, complete electrical control, and single-shot
readout of an exchange-only spin qubit. Full control via the exchange
interaction is fast, yielding a demonstrated 75 qubit rotations in under 2 ns.
Measurement and state tomography are performed using a maximum-likelihood
estimator method, allowing decoherence, leakage out of the qubit state space,
and measurement fidelity to be quantified. The methods developed here are
generally applicable to systems with state leakage, noisy measurements, and
non-orthogonal control axes.


title: Gap Opening by Extremely Low Mass Planets in a Viscous Disk

abstract:
  By numerically integrating the compressible Navier-Stokes equations in two
dimensions, we calculate the criterion for gap formation by a very low mass (q
~10^{-4}) protoplanet on a fixed orbit in a thin viscous disk. In contrast with
some previously proposed gap-opening criteria, we find that a planet can open a
gap even if the Hill radius is smaller than the disk scale height. Moreover, in
the low-viscosity limit, we find no minimum mass necessary to open a gap for a
planet held on a fixed orbit. In particular, a Neptune-mass planet will open a
gap in a minimum mass solar nebula with suitably low viscosity (\alpha
<10^{-4}). We find that the mass threshold scales as the square root of
viscosity in the low mass regime. This is because the gap width for critical
planet masses in this regime is a fixed multiple of the scale height, not of
the Hill radius of the planet.


title:
A complete architecture of integrated photonic circuits based on AND and
  NOT logic gates of exciton-polaritons in semiconductor microcavities

abstract:
  In this letter we introduce a complete photonic logic gate architecture,
making use of the non-linear and spintronic properties of exciton-polaritons in
semiconductor microcavities. This hybrid light-matter design is highly compact
and offers the advantages expected of photonic circuits including: no
distance-dependent loss or signal gradation; electrical isolation and immunity
to electromagnetic interference; reduced error-checking overhead; and direct
coupling to external light, useful for fibre optic communication.


title: On triangulations, quivers with potentials and mutations

abstract:
  In this survey article we give a brief account of constructions and results
concerning the quivers with potentials associated to triangulations of surfaces
with marked points. Besides the fact that the mutations of these quivers with
potentials are compatible with the flips of triangulations, we mention some
recent results on the representation type of Jacobian algebras and the
uniqueness of non-degenerate potentials. We also mention how the the quivers
with potentials associated to triangulations give rise to CY2 and CY3
triangulated categories that have turned out to be useful in the subject of
stability conditions and in theoretical physics.


title:
Embedding agents in business applications using enterprise integration
  patterns

abstract:
  This paper addresses the issue of integrating agents with a variety of
external resources and services, as found in enterprise computing environments.
We propose an approach for interfacing agents and existing message routing and
mediation engines based on the endpoint concept from the enterprise integration
patterns of Hohpe and Woolf. A design for agent endpoints is presented, and an
architecture for connecting the Jason agent platform to the Apache Camel
enterprise integration framework using this type of endpoint is described. The
approach is illustrated by means of a business process use case, and a number
of Camel routes are presented. These demonstrate the benefits of interfacing
agents to external services via a specialised message routing tool that
supports enterprise integration patterns.


title: Electron Heating in Quasi-Perpendicular Shocks

abstract:
  Seventy crossings of the Earths bow shock by the THEMIS satellites have been
used to study thermal electron heating in collisionless, quasi-perpendicular
shocks. It was found that the temperature increase of thermal electrons
differed from the magnetic field increase by factors as great as three, that
the parallel electron temperature increase was not produced by parallel
electric fields, and that the parallel and perpendicular electron temperature
increases were the same on the average. It was also found that the
perpendicular and parallel electron heating occurred simultaneously so that the
isotropization time is the same as the heating time. These results cannot be
explained by energy transfer from waves to electrons or by the motion of
magnetized electrons through the shock. Electric field fluctuations on the
scale of the electron gyro-diameter were found to be of finite amplitude in the
shock ramp, which requires that the electron trajectories be more random and
chaotic than orderly and adiabatic. The data may be explained by the large
amplitude electric field fluctuations that demagnetize electrons as they move
through the cross-shock electric field


title: HTC Scientific Computing in a Distributed Cloud Environment

abstract:
  This paper describes the use of a distributed cloud computing system for
high-throughput computing (HTC) scientific applications. The distributed cloud
computing system is composed of a number of separate
Infrastructure-as-a-Service (IaaS) clouds that are utilized in a unified
infrastructure. The distributed cloud has been in production-quality operation
for two years with approximately 500,000 completed jobs where a typical
workload has 500 simultaneous embarrassingly-parallel jobs that run for
approximately 12 hours. We review the design and implementation of the system
which is based on pre-existing components and a number of custom components. We
discuss the operation of the system, and describe our plans for the expansion
to more sites and increased computing capacity.


title: Scaling Analysis of Nanowire Phase Change Memory

abstract:
  This letter analyzes the scaling property of nanowire (NW) phase change
memory (PCM) using analytic and numerical methods. The scaling scenarios of the
three widely-used NW PCM peration schemes (constant electric field, voltage,
and current) are studied and compared. It is shown that if the device size is
downscaled by a factor of 1/k (k>1), the peration energy (current) will be
reduced by more than k3 (k) times, and the operation speed will be increased by
k2 times. It is also shown that more than 90% of operation energy is wasted as
thermal flux into substrate and electrodes. We predict that, if the wasted
thermal flux is effectively reduced by heat confinement technologies, the
energy consumed per RESET operation can be decreased from about 1 pJ to less
than 100 fJ. It is shown that reducing NW aspect ratio (AR) helps decreasing
PCM energy consumption. It is revealed that cross-cell thermal proximity
disturbance is counter-intuitively alleviated by scaling, leading to a
desirable scaling scenario.


title:
Low-bias electron transport properties of germanium telluride ultrathin
  films

abstract:
  The nanometer-scale size-dependent electronic transport properties of
crystalline (c-) and amorphous (a-) germanium telluride (GeTe) ultrathin films
sandwiched by titanium nitride (TiN) electrodes are investigated using ab
initio molecular dynamics (AIMD), density functional theory (DFT), and Green's
function calculations. We find that a-GeTe ultrathin films scaled down to about
38 Angstrom (12 atomic layers) still shows a band gap and the electrical
conductance is mainly due to electron transport via intra-gap states. If the
ultrathin films are further scaled, the a-GeTe band gap disappears due to
overlap of the two metal induced gap states (MIGS) regions near the TiN
electrodes, leading to sharp increase of a-GeTe conductance and significant
decrease of c-GeTe/a-GeTe conductance ratio. The c-GeTe/a-GeTe conductance
ratio drops below one order of magnitude if the ultrathin films are scaled
below about 33 Angstrom, making it difficult to reliably perform read
operations in thin film based phase change memory devices. This overlap of the
MIGS regions sets up the ultimate scaling limit of phase change memory
technology. Our results suggest that the ultimate scaling limit can be pushed
to even smaller size, by using phase change material (PCM) with larger
amorphous phase band gap than a-GeTe.


title: Surveillance Video Processing Using Compressive Sensing

abstract:
  A compressive sensing method combined with decomposition of a matrix formed
with image frames of a surveillance video into low rank and sparse matrices is
proposed to segment the background and extract moving objects in a surveillance
video. The video is acquired by compressive measurements, and the measurements
are used to reconstruct the video by a low rank and sparse decomposition of
matrix. The low rank component represents the background, and the sparse
component is used to identify moving objects in the surveillance video. The
decomposition is performed by an augmented Lagrangian alternating direction
method. Experiments are carried out to demonstrate that moving objects can be
reliably extracted with a small amount of measurements.


title:
Superconductivity in the noncentrosymmetric half-Heusler compound LuPtBi
  : A possible topological superconductor

abstract:
  We report superconductivity in the ternary half-Heusler compound LuPtBi, with
Tc = 1.0 K and Hc2 = 1.6 T. The crystal structure of LuPtBi lacks inversion
symmetry, hence the material is a noncentrosymmetric superconductor.
Magnetotransport data show semimetallic behavior in the normal state, which is
evidence for the importance of spin-orbit interaction. Theoretical calculations
indicate that the strong spin-orbit interaction in LuPtBi should cause strong
band inversion, making this material a promising candidate for 3D topological
superconductivity.


title: Stereochemistry of Polypeptide Conformation in Coarse Grained Analysis

abstract:
  The conformations available to polypeptides are determined by the interatomic
forces acting on the peptide units, whereby backbone torsion angles are
restricted as described by the Ramachandran plot. Although typical proteins are
composed predominantly from {\alpha}-helices and {\beta}-sheets, they
nevertheless adopt diverse tertiary structure, each folded as dictated by its
unique amino-acid sequence. Despite such uniqueness, however, the functioning
of many proteins involves changes between quite different conformations. The
study of large-scale conformational changes, particularly in large systems, is
facilitated by a coarse-grained representation such as provided by virtually
bonded C{\alpha} atoms. We have developed a virtual atom molecular mechanics
(VAMM) force field to describe conformational dynamics in proteins and a
VAMM-based algorithm for computing conformational transition pathways. Here we
describe the stereochemical analysis of proteins in this coarse-grained
representation, comparing the relevant plots in coarse-grained conformational
space to the corresponding Ramachandran plots, having contoured each at levels
determined statistically from residues in a large database. The distributions
shown for an all-{\alpha} protein, two all-{\beta} proteins and one
{\alpha}+{\beta} protein serve to relate the coarse-grained distributions to
the familiar Ramachandran plot.


title: A Stochastic Conjugate Gradient Method for Approximation of Functions

abstract:
  A stochastic conjugate gradient method for approximation of a function is
proposed. The proposed method avoids computing and storing the covariance
matrix in the normal equations for the least squares solution. In addition, the
method performs the conjugate gradient steps by using an inner product that is
based stochastic sampling. Theoretical analysis shows that the method is
convergent in probability. The method has applications in such fields as
predistortion for the linearization of power amplifiers.


title:
Experimental realization of quantum algorithm for solving linear systems
  of equations

abstract:
  Quantum computers have the potential of solving certain problems
exponentially faster than classical computers. Recently, Harrow, Hassidim and
Lloyd proposed a quantum algorithm for solving linear systems of equations:
given an $N\times{N}$ matrix $A$ and a vector $\vec b$, find the vector $\vec
x$ that satisfies $A\vec x = \vec b$. It has been shown that using the
algorithm one could obtain the solution encoded in a quantum state $|x$ using
$O(\log{N})$ quantum operations, while classical algorithms require at least
O(N) steps. If one is not interested in the solution $\vec{x}$ itself but
certain statistical feature of the solution ${x}|M|x$ ($M$ is some quantum
mechanical operator), the quantum algorithm will be able to achieve exponential
speedup over the best classical algorithm as $N$ grows. Here we report a
proof-of-concept experimental demonstration of the quantum algorithm using a
4-qubit nuclear magnetic resonance (NMR) quantum information processor. For all
the three sets of experiments with different choices of $\vec b$, we obtain the
solutions with over 96% fidelity. This experiment is a first implementation of
the algorithm. Because solving linear systems is a common problem in nearly all
fields of science and engineering, we will also discuss the implication of our
results on the potential of using quantum computers for solving practical
linear systems.


title: A new compressive video sensing framework for mobile broadcast

abstract:
  A new video coding method based on compressive sampling is proposed. In this
method, a video is coded using compressive measurements on video cubes. Video
reconstruction is performed by minimization of total variation (TV) of the
pixelwise DCT coefficients along the temporal direction. A new reconstruction
algorithm is developed from TVAL3, an efficient TV minimization algorithm based
on the alternating minimization and augmented Lagrangian methods. Video coding
with this method is inherently scalable, and has applications in mobile
broadcast.


title: Randomized partition trees for exact nearest neighbor search

abstract:
  The k-d tree was one of the first spatial data structures proposed for
nearest neighbor search. Its efficacy is diminished in high-dimensional spaces,
but several variants, with randomization and overlapping cells, have proved to
be successful in practice. We analyze three such schemes. We show that the
probability that they fail to find the nearest neighbor, for any data set and
any query point, is directly related to a simple potential function that
captures the difficulty of the point configuration. We then bound this
potential function in two situations of interest: the first, when data come
from a doubling measure, and the second, when the data are documents from a
topic model.


title: Brillouin cavity optomechanics with microfluidic devices

abstract:
  Cavity optomechanics allows the parametric coupling of phonon- and
photon-modes in microresonators and is presently investigated in a broad
variety of solid-state systems. Optomechanics with superfluids has been
proposed as a path towards ultra-low optical- and mechanical-dissipation.
However, there have been no optomechanics experiments reported with non-solid
phases of matter. Direct liquid immersion of optomechanics experiments is
challenging since the acoustic energy simply leaks out to the higher-impedance
liquid surrounding the device. Conversely, here we confine liquids inside
hollow resonators thereby enabling optical excitation of mechanical
whispering-gallery modes at frequencies ranging from 2 MHz to 11,000 MHz (for
example, with mechanical Q = 4700 at 99 MHz). Vibrations are sustained even
when we increase the fluid viscosity to be higher than that of blood. Our
device enables optomechanical investigation with liquids, while light is
conventionally coupled from the outer dry side of the capillary, and liquids
are provided by means of a standard microfluidic inlet.


title:
Shrinkage estimation of a mean matrix of a multivariate complex normal
  distribution

abstract:
  The problem of estimating a mean matrix of a multivariate complex normal
distribution with an unknown covariance matrix is considered under an invariant
loss function. By using complex versions of the Stein identity, the Stein-Haff
identity, and calculus on eigenvalues, a formula is obtained for an unbiased
estimate of the risk of an invariant class of estimators, from which several
minimax shrinkage estimators are constructed.


title: Editorial: Making GIScience Research More Open Access

abstract:
  This is the editorial for the special issue on "data-intensive geospatial
computing", which I guest edited with the International Journal of Geographical
Information Science (Taylor & Francis). As remarked in the editorial, the
special issue is particularly special in the sense that all source and data are
published together with the published papers. This editorial elaborates on
scholarly communication, with particular attention to publishing data alongside
papers and the emergence of open access journals, in order to make our research
more open access.


title: A converse to linear independence criteria, valid almost everywhere

abstract:
  We prove a weighted analogue of the Khintchine-Groshev Theorem, where the
distance to the nearest integer is replaced by the absolute value. This is
subsequently applied to proving the optimality of several linear independence
criteria over the field of rational numbers.


title:
Virtual decuplet effects on octet baryon masses in covariant baryon
  chiral perturbation theory

abstract:
  We extend a previous analysis of the lowest-lying octet baryon masses in
covariant baryon chiral perturbation theory (ChPT) by explicitly taking into
account the contribution of the virtual decuplet baryons. Up to
next-to-next-to-next-to-leading order (N$^3$LO), the effects of these heavier
degrees of freedom are systematically studied. Their effects on the light-quark
mass dependence of the octet baryon masses are shown to be relatively small and
can be absorbed by the available low-energy constants up to N$^3$LO.
Nevertheless, a better description of the finite-volume corrections of the
lattice QCD data can be achieved, particularly those with small $M_\phi L$
($<4$), which is demonstrated by a careful study of the NPLQCD and QCDSF-UKQCD
small-volume data. Finally, we show that the predicted pion- and
strangeness-baryon sigma terms are only slightly changed by the inclusion of
the virtual decuplet baryons.


title: On a Catalogue of Metrics for Evaluating Commercial Cloud Services

abstract:
  Given the continually increasing amount of commercial Cloud services in the
market, evaluation of different services plays a significant role in
cost-benefit analysis or decision making for choosing Cloud Computing. In
particular, employing suitable metrics is essential in evaluation
implementations. However, to the best of our knowledge, there is not any
systematic discussion about metrics for evaluating Cloud services. By using the
method of Systematic Literature Review (SLR), we have collected the de facto
metrics adopted in the existing Cloud services evaluation work. The collected
metrics were arranged following different Cloud service features to be
evaluated, which essentially constructed an evaluation metrics catalogue, as
shown in this paper. This metrics catalogue can be used to facilitate the
future practice and research in the area of Cloud services evaluation.
Moreover, considering metrics selection is a prerequisite of benchmark
selection in evaluation implementations, this work also supplements the
existing research in benchmarking the commercial Cloud services.


title:
Dissipative hydrodynamic evolution of hot quark matter at finite baryon
  density

abstract:
  High-energy heavy ion collider experiments at RHIC and LHC have revealed that
relativistic hydrodynamic models describe the hot and dense quark matter
quantitatively. In this study, I develop a novel dissipative hydrodynamic model
at finite baryon density to investigate the net baryon rapidity distribution.
The results show that the distribution is widened in hydrodynamic evolution,
which implies that the transparency of the collisions is effectively enhanced.
This suggests that the kinetic energy loss for medium production at the initial
stage could be larger. Furthermore, the net baryon distribution is found
sensitive to baryon diffusion, implying that dissipative hydrodynamic modeling
would be important for understanding the hot medium.


title: The Perturbed Maxwell Operator as Pseudodifferential Operator

abstract:
  As a first step to deriving effective dynamics and ray optics, we prove that
the perturbed periodic Maxwell operator in d = 3 can be seen as a
pseudodifferential operator. This necessitates a better understanding of the
periodic Maxwell operator M_0. In particular, we characterize the behavior of
M_0 and the physical initial states at small crystal momenta $k$ and small
frequencies |\omega|. Among other things, we prove that generically the band
spectrum is symmetric with respect to inversions at k = 0 and that there are
exactly 4 ground state bands with approximately linear dispersion near k = 0.