title:
Development of an Ideal Observer that Incorporates Nuisance Parameters
  and Processes List-Mode Data

abstract:
  Observer models were developed to process data in list-mode format in order
to perform binary discrimination tasks for use in an arms-control-treaty
context. Data used in this study was generated using GEANT4 Monte Carlo
simulations for photons using custom models of plutonium inspection objects and
a radiation imaging system. Observer model performance was evaluated and
presented using the area under the receiver operating characteristic curve. The
ideal observer was studied under both signal-known-exactly conditions and in
the presence of unknowns such as object orientation and absolute count-rate
variability; when these additional sources of randomness were present, their
incorporation into the observer yielded superior performance.


title: Physical Version of Singularity Resolution in the Observable Universe

abstract:
  Based on the equivalence of the two different types of measurement protocols
and the asymmetry between the Schr\"odinger and Heisenberg pictures, it has
been previously proposed that negative sea fills the universe as a
nondeterministic computation - a time-reversal process of the irreversible
computations presented since the big bang. The goal of this paper is to extend
the proposed subjective universe model, i.e., the universe as a quantum
measurement: Motivated by the relationship between quantum theory and classical
probability theory with continuity, it is argued that the frame of reference of
the observer may be identified with classical probability theory where its
choice, along with big bang singularity, should correspond to the quantum
observable. That is, the physical version of singularity resolution corresponds
to the case, where big bang singularity is equivalent to the continuity of the
negative sea, or aether, filling the universe as a frame of reference of the
observer. Moreover, based on the holographic principle, we identify the choice
of the observer with the degrees of freedom proportional to the Planck area on
the horizon. We also discuss that the continuity or infinity present in every
formal language of choice acceptable in nondeterministic computation may be
associated with the universal grammar proposed by Chomsky in linguistics.


title: Lectures on Springer theories and orbital integrals

abstract:
  These are the expanded lecture notes from the author's mini-course during the
graduate summer school of the Park City Math Institute in 2015. The main topics
covered are: geometry of Springer fibers, affine Springer fibers and Hitchin
fibers; representations of (affine) Weyl groups arising from these objects;
relation between affine Springer fibers and orbital integrals.


title:
General Solution to Sequential Linear Conformable Fractional
  Differential Equations With Constant Coefficients

abstract:
  In this work, we give the general solution sequential linear conformable
fractional differential equations in the case of constant coefficients for
{\alpha}(\in)(0,1]. In homogeneous case, we use a fractional exponential
function which generalizes the corresponding ordinary function. In
non-homogeneous case, we present to fractional the method of variation of
parameters for a particular solution of sequential linear conformable
fractional differential equations.


title: Decoherence of a quantum two-level system by spectral diffusion

abstract:
  We study the dephasing of an individual high-frequency tunneling two-level
system (TLS) due to its interaction with an ensemble of low-frequency thermal
TLSs which are described by the standard tunneling model (STM). We show that
the dephasing by the bath of TLSs explains both the dependence of the Ramsey
dephasing rate on an externally applied strain as well as its order of
magnitude, as observed in a recent experiment [J. Lisenfeld et al.]. However,
the theory based on the STM predicts the Hahn-echo protocol to be much more
efficient, yielding too low echo dephasing rates, as compared to the
experiment. Also the strain dependence of the echo dephasing rate predicted by
the STM does not agree with the measured quadratic dependence, which would fit
to a high-frequency white noise environment. We suggest that few fast TLSs
which are coupled much more strongly to the strain fields than the usual TLSs
of the STM give rise to such a white noise. This explains the magnitude and
strong fluctuations of the echo dephasing rate observed in the experiment.


title: A matrix model for random nilpotent groups

abstract:
  We study random torsion-free nilpotent groups generated by a pair of random
words of length $\ell$ in the standard generating set of $U_n(\mathbb{Z})$.
Specifically, we give asymptotic results about the step properties of the group
when the lengths of the generating words are functions of $n$. We show that the
threshold function for asymptotic abelianness is $\ell = c \sqrt{n}$, for which
the probability approaches $e^{-2c^2}$, and also that the threshold function
for having full-step, the same step as $U_n(\mathbb{Z})$, is between $c n^2$
and $c n^3$.


title:
Electromagnetic radiation as a probe of the initial state and of viscous
  dynamics in relativistic nuclear collisions

abstract:
  The penetrating nature of electromagnetic signals makes them suitable probes
to explore the properties of the strongly-interacting medium created in
relativistic nuclear collisions. We examine the effects of the initial
conditions and shear relaxation time on the spectra and flow coefficients of
electromagnetic probes, using an event-by-event 3+1D viscous hydrodynamic
simulation (MUSIC).


title:
Coherent photoproduction of vector mesons in heavy ion ultraperipheral
  collisions: Update for run 2 at the CERN Large Hadron Collider

abstract:
  We make predictions for the cross sections of coherent photoproduction of
$\rho$, $\phi$, $J/\psi$, $\psi(2S)$, and $\Upsilon(1S)$ mesons in Pb-Pb
ultraperipheral collisions (UPCs) at $\sqrt{s_{NN}}=5.02$ TeV in the kinematics
of run 2 at the Large Hadron Collider extending the approaches successfully
describing the available Pb-Pb UPC data at $\sqrt{s_{NN}}=2.76$ TeV. Our
results illustrate the important roles of hadronic fluctuations of the photon
and inelastic nuclear shadowing in photoproduction of light vector mesons on
nuclei and the large leading twist nuclear gluon shadowing in photoproduction
of quarkonia on nuclei. We show that the ratio of $\psi(2S)$ and $J/\psi$
photoproduction cross sections in Pb-Pb UPCs is largely determined by the ratio
of these cross sections on the proton. We also argue that UPCs with
electromagnetic excitations of the colliding ions followed by the forward
neutron emission allows one to significantly increase the range of photon
energies accessed in vector meson photoproduction on nuclei.


title: Inverted pendulum state of a polariton Rabi oscillator

abstract:
  Exciton-photon beats known as polariton Rabi oscillations in semiconductor
microcavities are usually excited by short pulses of light. We consider a
different pumping scheme, assuming a cw pumping of the Rabi oscillator from an
exciton reservoir. We account for the initial pulse of light setting the phase,
exciton decay due to exciton-phonon and exciton-exciton scattering, photon
leakage, and blueshift of the exciton resonance due to interactions. We find
non-trivial stationary solutions reminiscent of Kapitza pendulum, where
polaritons are accumulated at the upper branch while the lower branch empties.


title:
Private Information Retrieval from MDS Coded Data in Distributed Storage
  Systems

abstract:
  The problem of providing privacy, in the private information retrieval (PIR)
sense, to users requesting data from a distributed storage system (DSS), is
considered. The DSS is coded by an $(n,k,d)$ Maximum Distance Separable (MDS)
code to store the data reliably on unreliable storage nodes. Some of these
nodes can be spies which report to a third party, such as an oppressive regime,
which data is being requested by the user. An information theoretic PIR scheme
ensures that a user can satisfy its request while revealing, to the spy nodes,
no information on which data is being requested. A user can trivially achieve
PIR by downloading all the data in the DSS. However, this is not a feasible
solution due to its high communication cost. We construct PIR schemes with low
download communication cost. When there is $b=1$ spy node in the DSS, we
construct PIR schemes with download cost $\frac{1}{1-R}$ per unit of requested
data ($R=k/n$ is the code rate), achieving the information theoretic limit for
linear schemes. The proposed schemes are universal since they depend on the
code rate, but not on the generator matrix of the code. Also, when $b\leq
n-\delta k$, for some $\delta \in \mathbb{N^+}$, we construct linear PIR
schemes with $cPoP = \frac{b+\delta k}{\delta}$.


title: Near-optimal protocols in complex nonequilibrium transformations

abstract:
  The development of sophisticated experimental means to control nanoscale
systems has motivated efforts to design driving protocols which minimize the
energy dissipated to the environment. Computational models are a crucial tool
in this practical challenge. We describe a general method for sampling an
ensemble of finite-time, nonequilibrium protocols biased towards a low average
dissipation. We show that this scheme can be carried out very efficiently in
several limiting cases. As an application, we sample the ensemble of
low-dissipation protocols that invert the magnetization of a 2D Ising model and
explore how the diversity of the protocols varies in response to constraints on
the average dissipation. In this example, we find that there is a large set of
protocols with average dissipation close to the optimal value, which we argue
is a general phenomenon.


title: On the maximal diphoton width

abstract:
  Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal
width into $\gamma\gamma$ that a neutral scalar can acquire through a loop of
charged fermions or scalars as function of the maximal scale at which the
theory holds, taking into account vacuum (meta)stability bounds. We show how an
extra gauge symmetry can qualitatively weaken such bounds, and explore collider
probes and connections with Dark Matter.


title:
Comment on "Breakdown of the expansion of finite-size corrections to the
  hydrogen Lamb shift in moments of charge distribution"

abstract:
  In a recent paper, Hagelstein and Pascalutsa examine the error associated
with an expansion of proton structure corrections to the Lamb shift in terms of
moments of the charge distribution. They propose a small modification to a
conventional parameterization of the proton's charge form factor and show that
this can resolve the proton radius puzzle. However, while the size of the
"bump" they add to the form factor is small, it is large compared to the total
proton structure effects in the initial parameterization, yielding a final form
factor that is unphysical. Reducing their modification to the point where the
resulting form factor is physical does not allow for a resolution of the radius
puzzle.


title:
Bayesian Estimates of Astronomical Time Delays between Gravitationally
  Lensed Stochastic Light Curves

abstract:
  The gravitational field of a galaxy can act as a lens and deflect the light
emitted by a more distant object such as a quasar. Strong gravitational lensing
causes multiple images of the same quasar to appear in the sky. Since the light
in each gravitationally lensed image traverses a different path length from the
quasar to the Earth, fluctuations in the source brightness are observed in the
several images at different times. The time delay between these fluctuations
can be used to constrain cosmological parameters and can be inferred from the
time series of brightness data or light curves of each image. To estimate the
time delay, we construct a model based on a state-space representation for
irregularly observed time series generated by a latent continuous-time
Ornstein-Uhlenbeck process. We account for microlensing, an additional source
of independent long-term extrinsic variability, via a polynomial regression.
Our Bayesian strategy adopts a Metropolis-Hastings within Gibbs sampler. We
improve the sampler by using an ancillarity-sufficiency interweaving strategy
and adaptive Markov chain Monte Carlo. We introduce a profile likelihood of the
time delay as an approximation of its marginal posterior distribution. The
Bayesian and profile likelihood approaches complement each other, producing
almost identical results; the Bayesian method is more principled but the
profile likelihood is simpler to implement. We demonstrate our estimation
strategy using simulated data of doubly- and quadruply-lensed quasars, and
observed data from quasars Q0957+561 and J1029+2623.


title:
Interactions between discontinuities for binary mixture separation
  problem and hodograph method

abstract:
  The Cauchy problem for first-order PDE with the initial data which have a
piecewise discontinuities localized in different spatial points is completely
solved. The interactions between discontinuities arising after breakup of
initial discontinuities are studied with the help of the hodograph method. The
solution is constructed in analytical implicit form. To recovery the explicit
form of solution we propose the transformation of the PDEs into some ODEs on
the level lines (isochrones) of implicit solution. In particular, this method
allows us to solve the Goursat problem with initial data on characteristics.
The paper describes a specific problem for zone electrophoresis (method of the
mixture separation). However, the method proposed allows to solve any system of
two first-order quasilinear PDEs for which the second order linear PDE, arising
after the hodograph transformation, has the Riemann-Green function in explicit
form.

categories: math.AP math-ph math.MP math.NA physics.chem-ph


title: Latent-Class Hough Forests for 6 DoF Object Pose Estimation

abstract:
  In this paper we present Latent-Class Hough Forests, a method for object
detection and 6 DoF pose estimation in heavily cluttered and occluded
scenarios. We adapt a state of the art template matching feature into a
scale-invariant patch descriptor and integrate it into a regression forest
using a novel template-based split function. We train with positive samples
only and we treat class distributions at the leaf nodes as latent variables.
During testing we infer by iteratively updating these distributions, providing
accurate estimation of background clutter and foreground occlusions and, thus,
better detection rate. Furthermore, as a by-product, our Latent-Class Hough
Forests can provide accurate occlusion aware segmentation masks, even in the
multi-instance scenario. In addition to an existing public dataset, which
contains only single-instance sequences with large amounts of clutter, we have
collected two, more challenging, datasets for multiple-instance detection
containing heavy 2D and 3D clutter as well as foreground occlusions. We provide
extensive experiments on the various parameters of the framework such as patch
size, number of trees and number of iterations to infer class distributions at
test time. We also evaluate the Latent-Class Hough Forests on all datasets
where we outperform state of the art methods.


title: Dark Sunshine: Detecting Dark Matter through Dark Photons from the Sun

abstract:
  Dark matter may interact with the Standard Model through the kinetic mixing
of dark photons, $A'$, with Standard Model photons. Such dark matter will
accumulate in the Sun and annihilate into dark photons. The dark photons may
then leave the Sun and decay into pairs of charged Standard Model particles
that can be detected by the Alpha Magnetic Spectrometer. The directionality of
this "dark sunshine" is distinct from all astrophysical backgrounds, providing
an opportunity for unambiguous dark matter discovery by AMS. We perform a
complete analysis of this scenario including Sommerfeld enhancements of dark
matter annihilation and the effect of the Sun's magnetic field on the signal,
and we define a set of cuts to optimize the signal probability. With the three
years of data already collected, AMS may discover dark matter with mass 1 TeV
$\lesssim m_X \lesssim$ 10 TeV, dark photon masses $m_{A'} \sim \mathcal
O(100)$ MeV, and kinetic mixing parameters $10^{-10} \lesssim \varepsilon
\lesssim 10^{-8}$. The proposed search extends beyond existing beam dump and
supernova bounds, and it is complementary to direct detection, probing the same
region of parameter space for elastic dark matter, but potentially far more in
the case of inelastic dark matter.


title: Graphene-based extremely wide-angle tunable metamaterial absorber

abstract:
  We investigate the absorption properties of graphene-based anisotropic
metamaterial structures where the metamaterial layer possesses an
electromagnetic response corresponding to a near-zero permittivity. We find
that through analytical and numerical studies, near perfect absorption arises
over an unusually broad range of beam incidence angles. Due to the presence of
graphene, the absorption is tunable via a gate voltage, providing dynamic
control of the energy transmission. We show that this strongly enhanced
absorption arises due to a coupling between light and a fast wave-mode
propagating along the graphene/metamaterial hybrid.


title: Period-Luminosity-Colour Relation for Early-Type Contact Binaries

abstract:
  This work describes the analysis of 64 early-type, massive contact or
near-contact eclipsing systems from the Large Magellanic Cloud discovered by
the OGLE-III survey. It presents the determination of the
period-luminosity-colour relation followed by these objects, that is different
from the one previously known for late-type W UMa stars. The relation for
massive stars has a significantly steeper dependence on the colour, which is
related to a much higher bolometric correction, however it is shallower in the
period term. This leads to the conclusion, that the relation for the total
population of main sequence contact binaries is non-linear. When studied
separately, genuinely-contact and near-contact systems follow two slightly
different relations.


title: External inverse-Compton emission from jetted tidal disruption events

abstract:
  The recent discoveries of Swift J1644+57 and J2058+05 show that tidal
disruption events (TDEs) can launch relativistic jets. Super-Eddington
accretion produces a strong radiation field of order Eddington luminosity. In a
jetted TDE, electrons in the jet will inverse-Compton scatter the external
radiation field from the accretion disk and wind. Motivated by observations of
thermal optical-UV spectra in Swift J2058+05 and several other TDEs, we assume
the spectrum of the external radiation field intercepted by the relativistic
jet to be blackbody. Hot electrons in the jet scatter this thermal radiation
and produce luminosities 10^45-10^48 erg/s in the X/gamma-ray band.
  This model of thermal plus inverse-Compton radiation is applied to Swift
J2058+05. First, we show that the blackbody component in the optical-UV
spectrum most likely has its origin in the super-Eddington wind from the disk.
Then, using the observed blackbody component as the external radiation field,
we show that the X-ray luminosity and spectrum are consistent with the
inverse-Compton emission, under the following conditions: (1) the jet Lorentz
factor is ~5-10; (2) electrons in the jet have a powerlaw distribution with
minimum Lorentz factor ~1 and powerlaw index p = 2.4; (3) the wind is mildly
relativistic (Lorentz factor >~1.5) and has isotropic-equivalent mass-loss rate
~5 M_sun/yr. We describe the implications for jet composition and the radius
where jet energy is converted to radiation.


title:
Topological magnetic dipolar interaction and non-local electric
  magnetization control in topological insulator heterostructures

abstract:
  The magnetoelectric effect predicted in topological insulators makes
heterostructures that combine magnetic materials and such insulators promising
candidates for spintronics applications. Here, we theoretically consider a
setup that exhibits two well-separated interfaces between a topological
insulator and a ferromagnetic insulator. We show that there is a topological
magnetic dipole-dipole interaction stemming from long-range Coulomb
interactions. We analytically derive the magnetization dynamics at the two
interfaces and discuss how the long-range coupling can be applied to
non-locally induce the formation of a magnetic texture at one interface by
suitably gating the other interface.


title: ABC of multi-fractal spacetimes and fractional sea turtles

abstract:
  We clarify what it means to have a spacetime fractal geometry in quantum
gravity and show that its properties differ from those of usual fractals. A
weak and a strong definition of multi-scale and multi-fractal spacetimes are
given together with a sketch of the landscape of multi-scale theories of
gravitation. Then, in the context of the fractional theory with
$q$-derivatives, we explore the consequences of living in a multi-fractal
spacetime. To illustrate the behavior of a non-relativistic body, we take the
entertaining example of a sea turtle. We show that, when only the time
direction is fractal, sea turtles swim at a faster speed than in an ordinary
world, while they swim at a slower speed if only the spatial directions are
fractal. The latter type of geometry is the one most commonly found in quantum
gravity. For time-like fractals, relativistic objects can exceed the speed of
light, but strongly so only if their size is smaller than the range of
particle-physics interactions. We also find new results about log-oscillating
measures, the measure presentation and their role in physical observations and
in future extensions to nowhere-differentiable stochastic spacetimes.


title:
Response to comment on "Broken translational and rotational symmetry via
  charge stripe order in underdoped YBa2Cu3O6+y"

abstract:
  Fine questions our interpretation of unidirectional-stripes over
bidirectional-checkerboard, and illustrates his criticism by simulating a
momentum space structure consistent with our data and corresponding to a
checkerboard-looking real space density. Here we use a local
rotational-symmetry analysis to demonstrate that the simulated image is in
actuality composed of locally unidirectional modulations of the charge density,
consistent with our original conclusions.


title: Carbon Chains and Methanol toward Embedded Protostars

abstract:
  Large interstellar organic molecules are potential precursors of prebiotic
molecules. Their formation pathways and chemical relationships with one another
and simpler molecules are therefore of great interest. In this paper, we
address the relationship between two classes of large organic molecules, carbon
chains and saturated complex organic molecules (COMs), at the early stages of
star formation through observations of C4H and CH3OH. We surveyed these
molecules with the IRAM 30m telescope toward 16 deeply embedded low-mass
protostars selected from the Spitzer c2d ice survey. We find that CH3OH and C4H
are positively correlated indicating that these two classes of molecules can
coexist during the embedded protostellar stage. The C4H/CH3OH gas abundance
ratio tentatively correlates with the CH4/CH3OH ice abundance ratio in the same
lines of sight. This relationship supports a scenario where carbon chain
formation in protostellar envelopes begins with CH4 ice desorption.


title: Chaos in Matrix Models and Black Hole Evaporation

abstract:
  Is the evaporation of a black hole described by a unitary theory? In order to
shed light on this question ---especially aspects of this question such as a
black hole's negative specific heat---we consider the real-time dynamics of a
solitonic object in matrix quantum mechanics, which can be interpreted as a
black hole (black zero-brane) via holography. We point out that the chaotic
nature of the system combined with the flat directions of its potential
naturally leads to the emission of D0-branes from the black brane, which is
suppressed in the large $N$ limit. Simple arguments show that the black
zero-brane, like the Schwarzschild black hole, has negative specific heat, in
the sense that the temperature goes up when it evaporates by emitting
D0-branes. While the largest Lyapunov exponent grows during the evaporation,
the Kolmogorov-Sinai entropy decreases. These are consequences of the generic
properties of matrix models and gauge theory. Based on these results, we give a
possible geometric interpretation of the eigenvalue distribution of matrices in
terms of gravity.
  Applying the same argument in the M-theory parameter region, we provide a
scenario to derive the Hawking radiation of massless particles from the
Schwarzschild black hole. Finally, we suggest that by adding a fraction of the
quantum effects to the classical theory, we can obtain a matrix model whose
classical time evolution mimics the entire life of the black brane, from its
formation to the evaporation.


title: Exploring the Nature of Gravity

abstract:
  I clarify the differences between various approaches in the literature which
attempt to link gravity and thermodynamics. I then describe a new perspective
based on the following features: (1) As in the case of any other matter field,
the gravitational field equations should also remain unchanged if a constant is
added to the Lagrangian; in other words, the field equations of gravity should
remain invariant under the transformation $T^a_b \to T^a_b + \delta^a_b
$(constant). (2) Each event of spacetime has a certain number ($f$) of
microscopic degrees of freedom (`atoms of spacetime'). This quantity $f$ is
proportional to the area measure of an equi-geodesic surface, centered at that
event, when the geodesic distance tends to zero. The spacetime should have a
zero-point length in order for $f$ to remain finite. (3) The dynamics is
determined by extremizing the heat density at all events of the spacetime. The
heat density is the sum of a part contributed by matter and a part contributed
by the atoms of spacetime, with the latter being $L_P^{-4} f$. The implications
of this approach are discussed.


title:
Low-energy electromagnetic radiation as an indirect probe of black-hole
  evaporation

abstract:
  We study the influence of black-hole evaporation on light propagation. The
framework employed is based on the non-linear QED effective action at one-loop
level. We show that the light-cone condition is modified for low-energy
radiation due to black-hole evaporation. We discuss conditions under which the
phase velocity of this low-energy radiation is greater than $c$. We also
compute the modified light-deflection angle, which turns out to be
significantly different from the standard GR value for black-hole masses in the
range $M_\text{Pl} \ll M \lesssim 10^{19}\;M_\text{Pl}$.


title:
Pseudoscalar susceptibilities and quark condensates: chiral restoration
  and lattice screening masses

abstract:
  We derive the formal Ward identities relating pseudoscalar susceptibilities
and quark condensates in three-flavor QCD, including consistently the
$\eta$-$\eta'$ sector and the $U_A(1)$ anomaly. These identities are verified
in the low-energy realization provided by ChPT, both in the standard $SU(3)$
framework for the octet case and combining the use of the $U(3)$ framework and
the large-$N_c$ expansion of QCD to account properly for the nonet sector and
anomalous contributions. The analysis is performed including finite temperature
corrections as well as the calculation of $U(3)$ quark condensates and all
pseudoscalar susceptibilities, which together with the full set of Ward
identities, are new results of this work. Finally, the Ward identities are used
to derive scaling relations for pseudoscalar masses, which explain the behavior
with temperature of lattice screening masses near chiral symmetry restoration.


title: Designing Quantum Spin-Orbital Liquids in Artificial Mott Insulators

abstract:
  Quantum spin-orbital liquids are elusive strongly correlated states of matter
that emerge from quantum frustration between spin and orbital degrees of
freedom. A promising route towards the observation of those states is the
creation of artificial Mott insulators where antiferromagnetic correlations
between spins and orbitals can be designed. We show that Coulomb impurity
lattices on the surface of gapped honeycomb substrates, such as graphene on
SiC, can be used to simulate SU(4) symmetric spin-orbital lattice models. We
exploit the property that massive Dirac fermions form mid-gap bound states with
spin and valley degeneracies in the vicinity of a Coulomb impurity. Due to
electronic repulsion, the antiferromagnetic correlations of the impurity
lattice are driven by a super-exchange interaction with SU(4) symmetry, which
emerges from the bound states degeneracy at quarter filling. We propose that
quantum spin-orbital liquids can be engineered in artificially designed
solid-state systems at vastly higher temperatures than achievable in optical
lattices with cold atoms. We discuss the experimental setup and possible
scenarios for candidate quantum spin-liquids in Coulomb impurity lattices of
various geometries.


title: Rational Mixed Tate Motivic Graphs

abstract:
  In this paper, we study the combinatorics of a subcomplex of the Bloch-Kriz
cycle complex [4] used to construct the category of mixed Tate motives. The
algebraic cycles we consider properly contain the subalgebra of cycles that
correspond to multiple logarithms (as defined in [12]). We associate an algebra
of graphs to our subalgebra of algebraic cycles. We give a purely graphical
criterion for admissibilty. We show that sums of bivalent graphs correspond to
coboundary elements of the algebraic cycle complex. Finally, we compute the
Hodge realization for an infinite family of algebraic cycles represented by
sums of graphs that are not describable in the combinatorial language of [12].


title: Renormalization on noncommutative torus

abstract:
  We study a self-interacting scalar $\varphi^4$ theory on the $d$-dimensional
noncommutative torus. We determine, for the particular cases $d=2$ and $d=4$,
the counterterms required by one-loop renormalization. We discuss higher loops
in two dimensions and two-loop contributions to the self-energy in four
dimensions. Our analysis points toward the absence of any problems related to
the UV/IR mixing and thus to renormalizability of the theory. However, we find
another potentially troubling phenomenon which is a wild behavior of the
two-point amplitude as a function of the noncommutativity matrix $\theta$.


title:
SPOKES: an End-to-End Simulation Facility for Spectroscopic Cosmological
  Surveys

abstract:
  The nature of dark matter, dark energy and large-scale gravity pose some of
the most pressing questions in cosmology today. These fundamental questions
require highly precise measurements, and a number of wide-field spectroscopic
survey instruments are being designed to meet this requirement. A key component
in these experiments is the development of a simulation tool to forecast
science performance, define requirement flow-downs, optimize implementation,
demonstrate feasibility, and prepare for exploitation. We present SPOKES
(SPectrOscopic KEn Simulation), an end-to-end simulation facility for
spectroscopic cosmological surveys designed to address this challenge. SPOKES
is based on an integrated infrastructure, modular function organization,
coherent data handling and fast data access. These key features allow
reproducibility of pipeline runs, enable ease of use and provide flexibility to
update functions within the pipeline. The cyclic nature of the pipeline offers
the possibility to make the science output an efficient measure for design
optimization and feasibility testing. We present the architecture, first
science, and computational performance results of the simulation pipeline. The
framework is general, but for the benchmark tests, we use the Dark Energy
Spectrometer (DESpec), one of the early concepts for the upcoming project, the
Dark Energy Spectroscopic Instrument (DESI). We discuss how the SPOKES
framework enables a rigorous process to optimize and exploit spectroscopic
survey experiments in order to derive high-precision cosmological measurements
optimally.


title:
Differential equations and dispersion relations for Feynman amplitudes.
  The two-loop massive sunrise and the kite integral

abstract:
  It is shown that the study of the imaginary part and of the corresponding
dispersion relations of Feynman graph amplitudes within the differential
equations method can provide a powerful tool for the solution of the equations,
especially in the massive case. The main features of the approach are
illustrated by discussing the simple cases of the 1-loop self-mass and of a
particular vertex amplitude, and then used for the evaluation of the two-loop
massive sunrise and the QED kite graph (the problem studied by Sabry in 1962),
up to first order in the (d-4) expansion.


title:
Nematic quantum phase transition of composite Fermi liquids in
  half-filled Landau levels and their geometric response

abstract:
  We present a theory of the isotropic-nematic quantum phase transition in the
composite Fermi liquid arising in half-filled Landau levels. We show that the
quantum phase transition between the isotropic and the nematic phase is
triggered by an attractive quadrupolar interaction between electrons, as in the
case of conventional Fermi liquids. We derive the theory of the nematic state
and of the phase transition. This theory is based on the flux attachment
procedure which maps an electron liquid in half-filled Landau levels into the
composite Fermi liquid close to a nematic transition. We show that the local
fluctuations of the nematic order parameters act as an effective dynamical
metric interplaying with the underlying Chern-Simons gauge fields associated
with the flux attachment. Both the fluctuations of the Chern-Simons gauge field
and the nematic order parameter can destroy the composite fermion
quasiparticles and drive the system into a non-Fermi liquid state. The
effective field theory for the isotropic-nematic phase transition has $z = 3$
dynamical exponent due to Landau damping effects. We show that there is a Berry
phase type term which governs the effective dynamics of the nematic order
parameter fluctuations, which can be interpreted as a non-universal "Hall
viscosity" of the dynamical metric. We show that the effective field theory has
a Wen-Zee-type term. Both terms originate from the time-reversal breaking
fluctuation of the Chern-Simons gauge fields. We present a perturbative
computation of the Hall viscosity and also show that this term is also obtained
by a Ward identity. We show that the disclination of the nematic fluid, carries
an electric charge. We show that a resonance observed in radio-frequency
conductivity experiments can be interpreted as a Goldstone nematic mode gapped
by lattice effects.


title:
A Distributed Algorithm for Computing a Common Fixed Point of a Family
  of Paracontractions

abstract:
  A distributed algorithm is described for finding a common fixed point of a
family of $m>1$ nonlinear maps $M_i : \mathbb{R}^n \rightarrow \mathbb{R}^n$
assuming that each map is a paracontraction and that such a common fixed point
exists. The common fixed point is simultaneously computed by $m$ agents
assuming each agent $i$ knows only $M_i$, the current estimates of the fixed
point generated by its neighbors, and nothing more. Each agent recursively
updates its estimate of the fixed point by utilizing the current estimates
generated by each of its neighbors. Neighbor relations are characterized by a
time-dependent directed graph $\mathbb{N}(t)$ whose vertices correspond to
agents and whose arcs depict neighbor relations. It is shown that for any
family of paracontractions $M_i, i \in \{1,2,\ldots,m\}$ which has at least one
common fixed point, and any sequence of strongly connected neighbor graphs
$\mathbb{N}(t)$, $t=1,2,\ldots$, the algorithm causes all agent estimates to
converge to a common fixed point.


title: Knots and Links from Random Projections

abstract:
  In this paper we study a model of random knots obtained by fixing a space
curve in $n$-dimensional Euclidean space with $n>3$, and orthogonally
projecting the space curve on to random $3$ dimensional subspaces. By varying
the space curve we obtain different models of random parametrized knots, and we
will study how the expectation value of the curvature changes as a function of
the initial parametrized space curve. In the case when the initial data is a
pair of space curves, or more generally a pair of manifolds satisfying certain
conditions on their dimension, then we obtain models of random links for which
we will give methods to compute the second moment of the linking number. As an
application of our computations, we will study numerous models of random knots
and links, and how to recover these models by appropriately choosing the
initial space curves to be projected.


title: Direct Evidence of Octupole Deformation in Neutron-Rich $^{144}$Ba

abstract:
  The neutron-rich nucleus $^{144}$Ba ($t_{1/2}$=11.5 s) is expected to exhibit
some of the strongest octupole correlations among nuclei with mass numbers $A$
less than 200. Until now, indirect evidence for such strong correlations has
been inferred from observations such as enhanced $E1$ transitions and
interleaving positive- and negative-parity levels in the ground-state band. In
this experiment, the octupole strength was measured directly by sub-barrier,
multi-step Coulomb excitation of a post-accelerated 650-MeV $^{144}$Ba beam on
a 1.0-mg/cm$^2$ $^{208}$Pb target. The measured value of the matrix element,
$\langle 3_1^- \| \mathcal{M}(E3) \| 0_1^+ \rangle=0.65(^{+17}_{-23})$
$e$b$^{3/2}$, corresponds to a reduced $B(E3)$ transition probability of
48($^{+25}_{-34}$) W.u. This result represents an unambiguous determination of
the octupole collectivity, is larger than any available theoretical prediction,
and is consistent with octupole deformation.


title: Duality Structure, Asymptotic analysis and Emergent Fractal sets

abstract:
  A new, extended nonlinear framework of the ordinary real analysis
incorporating a novel concept of {\em duality structure} and its applications
into various nonlinear dynamical problems is presented. The duality structure
is an asymptotic property that should affect the late time asymptotic behaviour
of a nonlinear dynamical system in a nontrivial way leading naturally to
signatures generic to a complex system. We argue that the present formalism
would offer a natural framework to understand the abundance of complex systems
in natural, biological, financial and related problems. We show that the power
law attenuation of a dispersive, lossy wave equation, conventionally deduced
from fractional calculus techniques, could actually arise from the present
asymptotic duality structure. Differentiability on a Cantor type fractal set is
also formulated.


title: Emergent Super-Virasoro on Magnetic Branes

abstract:
  The low energy limit of the stress tensor, gauge current, and supercurrent
two-point correlators are calculated in the background of the supersymmetric
magnetic brane solution to gauged five-dimensional supergravity constructed by
Almuhairi and Polchinski. The resulting correlators provide evidence for the
emergence of an N=2 super-Virasoro algebra of right-movers, in addition to a
bosonic Virasoro algebra and a $U(1) \oplus U(1)$-current algebra of
left-movers (or the parity transform of left- and right-movers depending on the
sign of the magnetic field), in the holographically dual strongly interacting
two-dimensional effective field theory of the lowest Landau level.


title:
Entanglement Entropy Renormalization for the NC scalar field coupled to
  classical BTZ geometry

abstract:
  In this work, we consider a noncommutative (NC) massless scalar field coupled
to the classical nonrotational BTZ geometry. In a manner of the theories where
the gravity emerges from the underlying scalar field theory, we study the
effective action and the entropy derived from this noncommutative model. In
particular, the entropy is calculated by making use of the two different
approaches, the brick wall method and the heat kernel method designed for
spaces with conical singularity. We show that the UV divergent structures of
the entropy, obtained through these two different methods, agree with each
other. It is also shown that the same renormalization condition that removes
the infinities from the effective action can also be used to renormalize the
entanglement entropy for the same system. Besides, the interesting feature of
the NC model considered here is that it allows an interpretation in terms of an
equivalent system comprising of a commutative massive scalar field, but in a
modified geometry; that of the rotational BTZ black hole, the result that hints
at a duality between the commutative and noncommutative systems in the
background of a BTZ black hole.


title:
Full range of proximity effect probed with
  Superconductor/Graphene/Superconductor junctions

abstract:
  The high tunability of the density of states of graphene makes it an ideal
probe of quantum transport in different regimes. In particular, the
supercurrent that can flow through a non-superconducting (N) material connected
to two superconducting electrodes, crucially depends on the lenghth of the N
relative to the superconducting coherence length. Using graphene as the N
material we have investigated the full range of the superconducting proximity
effect, from short to long diffusive junctions. By combining several
S/graphene/S samples with different contacts and lengths, and measuring their
gate-dependent critical currents ($ I_c $) and normal state resistance $ R_N $,
we compare the product $eR_NI_c$ to the relevant energies, the Thouless energy
in long junctions and the superconducting gap of the contacts in short
junctions, over three orders of magnitude of Thouless energy. The experimental
variations strikingly follow a universal law, close to the predictions of the
proximity effect both in the long and short junction regime, as well as in the
crossover region, thereby revealing the interplay of the different energy
scales. Differences in the numerical coefficients reveal the crucial role
played by the interfacial barrier between graphene and the superconducting
electrodes, which reduces the supercurrent in both short and long junctions.
Surprisingly the reduction of supercurrent is independent of the gate voltage
and of the nature of the electrodes. A reduced induced gap and Thouless energy
are extracted, revealing the role played by the dwell time in the barrier in
the short junction, and an effective increased diffusion time in the long
junction. We compare our results to the theoretical predictions of Usadel
equations and numerical simulations which better reproduce experiments with
imperfect NS interfaces.


title: No-slip billiards in dimension two

abstract:
  We investigate the dynamics of no-slip billiards, a model in which small
rotating disks may exchange linear and angular momentum at collisions with the
boundary. We give new results on periodicity and boundedness of orbits which
suggest that a class of billiards (including all polygons) is not ergodic.
Computer generated phase portraits demonstrate non-ergodic features, suggesting
chaotic no-slip billiards cannot readily be constructed using the common
techniques for generating chaos in standard billiards.


title:
Dynamic Error in Strain Induced Magnetization Reversal of Nanomagnets
  due to Incoherent Switching and Formation of Metastable States: A
  Size-dependent Study

abstract:
  Modulation of stress anisotropy of magnetostrictive nanomagnets with strain
offers an extremely energy-efficient method of magnetization reversal. The
reversal process, however, is often incoherent and hence error-prone in the
presence of thermal noise at room temperature. Occurrence of incoherent
metastable states in the potential landscape of the nanomagnet can further
exacerbate the error. Stochastic micromagnetic simulations at room temperature
are used to understand and calculate energy dissipations and switching error
probabilities in this important magnetization switching methodology. We find
that these quantities have an intriguing dependence on nanomagnet size: small
nanomagnets perform better owing to the fact that they are more resilient to
the formation of metastable states and magnetization dynamics in them is more
coherent. However, for a fixed stress anisotropy energy density, smaller
nanomagnets will also have poorer resilience against thermal instability. Thus,
the challenge in straintronics is to maximize the stress anisotropy energy
density by developing materials and processes that yield the largest
magnetostriction.


title: Electrodynamics and spacetime geometry I: Foundations

abstract:
  We explore the intimate connection between spacetime geometry and
electrodynamics. This link is already implicit in the constitutive relations
between the field strengths and excitations, which are an essential part of the
axiomatic structure of electromagnetism, clearly formulated via integration
theory and differential forms. We briefly review the foundations of
electromagnetism based on charge and magnetic flux conservation, the Lorentz
force and the constitutive relations which introduce the spacetime metric. We
then proceed with the tensor formulation by assuming local, linear, homogeneous
and isotropic constitutive relations, and explore the physical, observable
consequences of Maxwell's equations in curved spacetime. The field equations,
charge conservation and the Lorentz force are explicitly expressed in general
(pseudo) Riemanian manifolds. The generalized Gauss and Maxwell-Amp\`{e}re
laws, as well as the wave equations, reveal potentially interesting
astrophysical applications. In all cases new electromagnetic couplings and
related phenomena are induced by spacetime curvature. The implications and
possible applications for gravity waves detection are briefly addressed. At the
foundational level, we discuss the possibility of generalizing the vacuum
constitutive relations, by relaxing the fixed conditions of homogeneity and
isotropy, and by assuming that the symmetry properties of the electro-vacuum
follow the spacetime isometries. The implications of this extension are briefly
discussed in the context of the intimate connection between electromagnetism
and the geometry (and causal structure) of spacetime.


title:
Distant activity of 67P/Churyumov-Gerasimenko in 2014: Ground-based
  results during the Rosetta pre-landing phase

abstract:
  As the ESA Rosetta mission approached, orbited, and sent a lander to comet
67P/Churyumov-Gerasimenko in 2014, a large campaign of ground-based
observations also followed the comet. We constrain the total activity level of
the comet by photometry and spectroscopy to place Rosetta results in context
and to understand the large-scale structure of the comet's coma pre-perihelion.
We performed observations using a number of telescopes, but concentrate on
results from the 8m VLT and Gemini South telescopes in Chile. We use R-band
imaging to measure the dust coma contribution to the comet's brightness and
UV-visible spectroscopy to search for gas emissions, primarily using VLT/FORS.
In addition we imaged the comet in near-infrared wavelengths (JHK) in late 2014
with Gemini-S/Flamingos 2. We find that the comet was already active in early
2014 at heliocentric distances beyond 4 au. The evolution of the total activity
(measured by dust) followed previous predictions. No gas emissions were
detected despite sensitive searches. The comet maintains a similar level of
activity from orbit to orbit, and is in that sense predictable, meaning that
Rosetta results correspond to typical behaviour for this comet. The gas
production (for CN at least) is highly asymmetric with respect to perihelion,
as our upper limits are below the measured production rates for similar
distances post-perihelion in previous orbits.


title:
Modeling and Experiment of the Suspended Seismometer Concept for
  Attenuating the Contribution of Tilt Motion in Horizontal Measurements

abstract:
  Tilt-horizontal coupling in inertial sensors limits the performance of active
isolation systems such as those used in gravitational wave detectors. Inertial
rotation sensors can be used to subtract the tilt component from the signal
produced by horizontal inertial sensors, but such techniques are often limited
by the sensor noise of the tilt measurement. A different approach is to
mechanically filter the tilt transmitted to the horizontal inertial sensor, as
discussed in this article. This technique does not require an auxiliary
rotation sensor, and can produce a lower noise measurement. The concept
investigated uses a mechanical suspension to isolate the inertial sensor from
input tilt. Modeling and simulations show that such a configuration can be used
to adequately attenuate the tilt transmitted to the instrument, while
maintaining translation sensitivity in the frequency band of interest. The
analysis is supported by experimental results showing that this approach is a
viable solution to overcome the tilt problem in the field of active inertial
isolation.


title:
On splitting rank of non-compact type symmetric spaces and bounded
  cohomology

abstract:
  Let $X=G/K$ be a higher rank symmetric space of non-compact type, where $G$
is the connected component of the isometry group of $X$. We define the
splitting rank of $X$, denoted by $\text{srk}(X)$, to be the maximal dimension
of a totally geodesic submanifold $Y\subset X$ which splits off an isometric
$\mathbb R$-factor. We compute explicitly the splitting rank for each
irreducible symmetric space. For an arbitrary (not necessarily irreducible)
symmetric space, we show that the comparison map
$\eta:H^{*}_{c,b}(G,\mathbb{R})\rightarrow H^{*}_c(G,\mathbb{R})$ is surjective
in degrees $*\geq \text{srk}(X)+2$, provided $X$ has no small direct factors.


title: Some unified integrals associated with Bessel-Struve kernel function

abstract:
  In this paper, we discuss the generalized integral formula involving
Bessel-Struve kernel function $S_{\alpha }\left( \lambda z\right) $, which
expressed in terms of generalized Wright functions. Many interesting special
cases also obtained in this study.


title: Time Really Passes, Science Can't Deny That

abstract:
  Today's science provides quite a lean picture of time as a mere geometric
evolution parameter. I argue that time is much richer. In particular, I argue
that besides the geometric time, there is creative time, when objective chance
events happen. The existence of the latter follows straight from the existence
of free-will. Following the french philosopher Lequyer, I argue that free-will
is a prerequisite for the possibility to have rational argumentations, hence
can't be denied. Consequently, science can't deny the existence of creative
time and thus that time really passes.


title: Variational methods for fractional $q$-Sturm--Liouville Problems

abstract:
  In this paper, we formulate a regular $q$-fractional Sturm--Liouville problem
(qFSLP) which includes the left-sided Riemann--Liouville and the right-sided
Caputo $q$-fractional derivatives of the same order $\alpha$, $\alpha\in
(0,1)$. We introduce the essential $q$-fractional variational analysis needed
in proving the existence of a countable set of real eigenvalues and associated
orthogonal eigenfunctions for the regular qFSLP when $\alpha>1/2$ associated
with the boundary condition $y(0)=y(a)=0$. A criteria for the first eigenvalue
is proved. Examples are included. These results are a generalization of the
integer regular $q$-Sturm--Liouville problem introduced by Annaby and Mansour
in [1].


title: Reactor antineutrino fluxes - status and challenges

abstract:
  In this contribution we describe the current understanding of reactor
antineutrino fluxes and point out some recent developments. This is not
intended to be a complete review of this vast topic but merely a selection of
observations and remarks, which despite their incompleteness, will highlight
the status and the challenges of this field.


title: On Fractional q-Sturm--Liouville problems

abstract:
  In this paper, we formulate a regular $q$-fractional Sturm--Liouville problem
(qFSLP) which includes the left-sided Riemann--Liouville and the right-sided
Caputo q-fractional derivatives of the same order $\alpha$, $\alpha\in (0,1)$.
The properties of the eigenvalues and the eigenfunctions are investigated. A
$q$-fractional version of the Wronskian is defined and its relation to the
simplicity of the eigenfunctions is verified. We use the fixed point theorem to
introduce a sufficient condition on eigenvalues for the existence and
uniqueness of the associated eigenfunctions when $\alpha>1/2$. These results
are a generalization of the integer regular $q$-Sturm--Liouville problem
introduced by Annaby and Mansour in[1]. An example for a qFSLP whose
eigenfunctions are little $q$-Jacobi polynomials is introduced.


title:
Epidemics on networks with heterogeneous population and stochastic
  infection rates

abstract:
  In this paper we study the diffusion of an SIS-type epidemics on a network
under the presence of a random environment, that enters in the definition of
the infection rates of the nodes. Accordingly, we model the infection rates in
the form of independent stochastic processes. To analyze the problem, we apply
a mean field approximation, which allows to get a stochastic differential
equations for the probability of infection in each node, and classical tools
about stability, which require to find suitable Lyapunov's functions. Here, we
find conditions which guarantee, respectively, extinction and stochastic
persistence of the epidemics. We show that there exists two regions, given in
terms of the coefficients of the model, one where the system goes to extinction
almost surely, and the other where it is stochastic permanent. These two
regions are, unfortunately, not adjacent, as there is a gap between them, whose
extension depends on the specific level of noise. In this last region, we
perform numerical analysis to suggest the true behavior of the solution.


title: Valence-quark distribution functions in the kaon and pion

abstract:
  We describe expressions for pion and kaon dressed-quark distribution
functions that incorporate contributions from gluons which bind quarks into
these mesons and hence overcome a flaw of the commonly used handbag
approximation. The distributions therewith obtained are purely valence in
character, ensuring that dressed-quarks carry all a meson's momentum at a
characteristic hadronic scale and vanishing as $(1-x)^2$ when Bjorken-$x\to 1$.
Comparing such distributions within the pion and kaon, it is apparent that the
size of SU(3)-flavour symmetry breaking in meson parton distribution functions
is modulated by the flavour dependence of dynamical chiral symmetry breaking.
Corrections to these leading-order formulae may be divided into two classes,
responsible for shifting dressed-quark momentum into glue and sea-quarks.
Working with available empirical information, we build an algebraic framework
that is capable of expressing the principal impact of both classes of
corrections. This enables a realistic comparison with experiment which allows
us to identify and highlight basic features of measurable pion and kaon
valence-quark distributions. We find that whereas roughly two-thirds of the
pion's light-front momentum is carried by valence dressed-quarks at a
characteristic hadronic scale, this fraction rises to 95% in the kaon; evolving
distributions with these features to a scale typical of available Drell-Yan
data produces a kaon-to-pion ratio of u-quark distributions that is in
agreement with the single existing data set; and predict a u-quark distribution
within the pion that agrees with a modern reappraisal of $\pi N$ Drell-Yan
data. Precise new data are essential in order to validate this reappraisal and
because a single modest-quality measurement of the kaon-to-pion ratio cannot be
considered definitive.


title: On 4d rank-one N=3 superconformal field theories

abstract:
  We study the properties of 4d N=3 superconformal field theories whose rank is
one, i.e. those that reduce to a single vector multiplet on their moduli space
of vacua. We find that the moduli space can only be of the form C^3/Z_k for
k=1,2,3,4,6, and that the supersymmetry automatically enhances to N=4 for
k=1,2. In addition, we determine the central charges a and c in terms of k, and
construct the associated 2d chiral algebras, which turn out to be exotic N=2
supersymmetric W-algebras.


title:
Energetic emissions from deconfinement in compact stars and their
  relation to the critical end point in the QCD phase diagram

abstract:
  In this work we study the case of deconfinement in compact star interiors in
the presence of a strong first order phase transition associated to a critical
end point in the QCD phase diagram. Neutron stars fulfilling these conditions
show a third branch in the mass-radius diagram with the first and second
branches being the white dwarfs and neutron stars configurations. The
transition to the third branch can be reached by a pure hadronic neutron star
through an induced collapse releasing energy that corresponds to a mass-energy
difference between the second and third branch configurations. Physical
outcomes of this phenomenon that can potentially explain the already detected
astrophysical signals are discussed. In particular we present energy
estimations for the case of a fast radio burst, seen as a double-peak structure
in the object's light curve.


title: Geometry of the uniform spanning forest components in high dimensions

abstract:
  In this note we study the geometry of the component of the origin in the
Uniform Spanning Forest of $\mathbb{Z}^d$, as well as in the Uniform Spanning
Tree of wired subgraphs of $\mathbb{Z}^d$, when $d \ge 5$. In particular, we
study connectivity properties with respect to the Euclidean and the intrinsic
distance. We intend to supplement these with further estimates in the future.
We are making this preliminary note available, as one of our estimates is used
in work of Bhupatiraju, Hanson and J\'arai on sandpiles.


title: Level-set methods for convex optimization

abstract:
  Convex optimization problems arising in applications often have favorable
objective functions and complicated constraints, thereby precluding first-order
methods from being immediately applicable. We describe an approach that
exchanges the roles of the objective and constraint functions, and instead
approximately solves a sequence of parametric level-set problems. A
zero-finding procedure, based on inexact function evaluations and possibly
inexact derivative information, leads to an efficient solution scheme for the
original problem. We describe the theoretical and practical properties of this
approach for a broad range of problems, including low-rank semidefinite
optimization, sparse optimization, and generalized linear models for inference.


title: Nega-$\tilde Q$-representation of real numbers

abstract:
  The article is devoted to modeling of the nega-$\tilde Q$-representation of
real numbers. The representation is a generalization of representation by
alternating Cantor series and positive $\tilde Q$-representation is a
generalization of representation of real numbers by the positive Cantor series.
Analytic and geometric approach are used for modeling of nega-$\tilde
Q$-representation. Advantages and disadvantages of these approaches are
investigated, the representation is modeled.
  The investigation was represented in seminar on fractal analysis of Institute
of Mathematics of the National Academy of Sciences of Ukraine on, October 30,
2014 (http://www.imath.kiev.ua/events/index.php?seminarId=21&archiv=1) and
International Conference "Probability, Reliability and Stochastic
Optimization", Kyiv, April 7-10, 2015.


title:
Black hole thermodynamics from a variational principle: Asymptotically
  conical backgrounds

abstract:
  The variational problem of gravity theories is directly related to black hole
thermodynamics. For asymptotically locally AdS backgrounds it is known that
holographic renormalization results in a variational principle in terms of
equivalence classes of boundary data under the local asymptotic symmetries of
the theory, which automatically leads to finite conserved charges satisfying
the first law of thermodynamics. We show that this connection holds well beyond
asymptotically AdS black holes. In particular, we formulate the variational
problem for $\mathcal{N}=2$ STU supergravity in four dimensions with boundary
conditions corresponding to those obeyed by the so called `subtracted
geometries'. We show that such boundary conditions can be imposed covariantly
in terms of a set of asymptotic second class constraints, and we derive the
appropriate boundary terms that render the variational problem well posed in
two different duality frames of the STU model. This allows us to define finite
conserved charges associated with any asymptotic Killing vector and to
demonstrate that these charges satisfy the Smarr formula and the first law of
thermodynamics. Moreover, by uplifting the theory to five dimensions and then
reducing on a 2-sphere, we provide a precise map between the thermodynamic
observables of the subtracted geometries and those of the BTZ black hole.
Surface terms play a crucial role in this identification.


title: A View of Fog Computing from Networking Perspective

abstract:
  With smart devices, particular smartphones, becoming our everyday companions,
the ubiquitous mobile Internet and computing applications pervade people's
daily lives. With the surge demand on high-quality mobile services at anywhere,
how to address the ubiquitous user demand and accommodate the explosive growth
of mobile traffics is the key issue of the next generation mobile networks. The
Fog computing is a promising solution towards this goal. Fog computing extends
cloud computing by providing virtualized resources and engaged location-based
services to the edge of the mobile networks so as to better serve mobile
traffics. Therefore, Fog computing is a lubricant of the combination of cloud
computing and mobile applications. In this article, we outline the main
features of Fog computing and describe its concept, architecture and design
goals. Lastly, we discuss some of the future research issues from the
networking perspective.


title:
Unsupervised Regenerative Learning of Hierarchical Features in Spiking
  Deep Networks for Object Recognition

abstract:
  We present a spike-based unsupervised regenerative learning scheme to train
Spiking Deep Networks (SpikeCNN) for object recognition problems using
biologically realistic leaky integrate-and-fire neurons. The training
methodology is based on the Auto-Encoder learning model wherein the
hierarchical network is trained layer wise using the encoder-decoder principle.
Regenerative learning uses spike-timing information and inherent latencies to
update the weights and learn representative levels for each convolutional layer
in an unsupervised manner. The features learnt from the final layer in the
hierarchy are then fed to an output layer. The output layer is trained with
supervision by showing a fraction of the labeled training dataset and performs
the overall classification of the input. Our proposed methodology yields
0.92%/29.84% classification error on MNIST/CIFAR10 datasets which is comparable
with state-of-the-art results. The proposed methodology also introduces
sparsity in the hierarchical feature representations on account of event-based
coding resulting in computationally efficient learning.


title: Linear codes with a few weights from inhomogeneous quadratic functions

abstract:
  Linear codes with few weights have been an interesting subject of study for
many years, as these codes have applications in secrete sharing, authentication
codes, association schemes, and strongly regular graphs. In this paper, linear
codes with a few weights are constructed from inhomogeneous quadratic functions
over the finite field $\gf(p)$, where $p$ is an odd prime. They include some
earlier linear codes as special cases. The weight distributions of these linear
codes are also determined.


title:
Full Gradient Stabilized Cut Finite Element Methods for Surface Partial
  Differential Equations

abstract:
  We propose and analyze a new stabilized cut finite element method for the
Laplace-Beltrami operator on a closed surface. The new stabilization term
provides control of the full $\mathbb{R}^3$ gradient on the active mesh
consisting of the elements that intersect the surface. Compared to face
stabilization, based on controlling the jumps in the normal gradient across
faces between elements in the active mesh, the full gradient stabilization is
easier to implement and does not significantly increase the number of nonzero
elements in the mass and stiffness matrices. The full gradient stabilization
term may be combined with a variational formulation of the Laplace-Beltrami
operator based on tangential or full gradients and we present a simple and
unified analysis that covers both cases. The full gradient stabilization term
gives rise to a consistency error which, however, is of optimal order for
piecewise linear elements, and we obtain optimal order a priori error estimates
in the energy and $L^2$ norms as well as an optimal bound of the condition
number. Finally, we present detailed numerical examples where we in particular
study the sensitivity of the condition number and error on the stabilization
parameter.


title:
Continuous functions with complicated local structure that defined in
  terms of alternating Cantor series representation of numbers

abstract:
  The article is devoted to one infinite parametric class of continuous
functions with complicated local structure. In the article differential,
integral, self-affine and other properties of functions, that their argument is
represented by the alternating Cantor series are investigated. The functional
equations systems, that investigating functions are unique solution of these
systems in the class of determined and bounded on $[0;1]$ functions are
indicated.
  The investigation was represented in seminar on fractal analysis of Institute
of Mathematics of the National Academy of Sciences of Ukraine on, October 16,
2014 (http://www.imath.kiev.ua/events/index.php?seminarId=21&archiv=1).
  The following investigations in the list of references in the article one can
to find by the corresponding links: [6]
(http://fmi.npu.edu.ua/images/files/publications/naukchasopys1/NZ2013_15.pdf )
[7]
(http://fmi.npu.edu.ua/images/files/publications/naukchasopys1/NZ2013_14.pdf)
[8]
(http://fmi.npu.edu.ua/images/files/publications/naukchasopys1/NZ2012_13_2.pdf)
[9](http://www.ekmair.ukma.edu.ua/bitstream/handle/123456789/7409/Serbeniuk_Funktsii_oznacheni_systemamy.pdf)


title: Canonical surfaces of higher degree

abstract:
  We consider a family of surfaces of general type $S$ with $K_S$ ample, having
$K^2_S = 24, p_g (S) = 6, q(S)=0$. We prove that for these surfaces the
canonical system is base point free and yields an embedding $\Phi_1 : S
\rightarrow \mathbb{P}^5$.
  This result answers a question posed by G. and M. Kapustka.
  We discuss some related open problems, concerning also the case $p_g(S) = 5$,
where one requires the canonical map to be birational onto its image.


title: Enhancing the filtered derived category

abstract:
  The filtered derived category of an abelian category has played a useful role
in subjects including geometric representation theory, mixed Hodge modules, and
the theory of motives. We develop a natural generalization using current
methods of homotopical algebra, in the formalisms of stable
infinity-categories, stable model categories, and pretriangulated,
idempotent-complete dg categories. We characterize the filtered stable
infinity-category Fil(C) of a stable infinity-category C as the left exact
localization of sequences in C along the infinity-categorical version of
completion (and prove analogous model and dg category statements). We also
spell out how these constructions interact with spectral sequences and monoidal
structures. As examples of this machinery, we construct a stable model category
of filtered D-modules and develop the rudiments of a theory of filtered operads
and filtered algebras over operads.


title: Market-based Microgrid Optimal Scheduling

abstract:
  This paper presents an optimal scheduling model for a microgrid participating
in the electricity distribution market in interaction with the Distribution
Market Operator (DMO). The DMO is a concept proposed here, which administers
the established electricity market in the distribution level, i.e., similar to
the role of Independent System Operator (ISO) in the wholesale electricity
market, sets electricity prices, determines the amounts of the power exchange
between market participators, and interacts with the ISO. Considering a
predetermined main grid power transfer to the microgrid, the microgrid
scheduling problem will aim at balancing the power supply and demand while
taking financial objectives into account. A stochastic programming method is
employed to model prevailing uncertainties in the microgrid grid-connected and
islanded operations. Numerical simulations exhibit the application and the
effectiveness of the proposed market-based microgrid scheduling model.


title:
Towards Better Exploiting Convolutional Neural Networks for Remote
  Sensing Scene Classification

abstract:
  We present an analysis of three possible strategies for exploiting the power
of existing convolutional neural networks (ConvNets) in different scenarios
from the ones they were trained: full training, fine tuning, and using ConvNets
as feature extractors. In many applications, especially including remote
sensing, it is not feasible to fully design and train a new ConvNet, as this
usually requires a considerable amount of labeled data and demands high
computational costs. Therefore, it is important to understand how to obtain the
best profit from existing ConvNets. We perform experiments with six popular
ConvNets using three remote sensing datasets. We also compare ConvNets in each
strategy with existing descriptors and with state-of-the-art baselines. Results
point that fine tuning tends to be the best performing strategy. In fact, using
the features from the fine-tuned ConvNet with linear SVM obtains the best
results. We also achieved state-of-the-art results for the three datasets used.


title: Trees and gaps from a construction scheme

abstract:
  We present natural constructions of trees and gaps using a quite general
construction scheme. In particular, we solve a natural problem about
$(\omega_1, \omega_1)$-gaps. As it is well known $(\omega_1, \omega_1)$-gaps
can sometimes be filled in $\omega_1$-preserving forcing extensions of the
set-theoretic universe. There are two natural conditions, dubbed $S$ and $T$
below, that guarantee the existence of such forcing extensions. The condition
$T$ is a natural strengthening of the condition $S$ and was motivated by the
numerous analogies between $(\omega_1,\omega_1)$-gaps and certain trees of
height $\omega_1.$ It turns out that the condition $S$ is in fact equivalent to
the existence of such forcing extensions but we show that the condition $T$ is
strictly stronger by proving that it is consistent that there are fillable
$(\omega_1, \omega_1)$-gaps (i.e., S-gaps) but no T-gaps.


title: Protocol for Fermionic Positive-Operator-Valued Measures

abstract:
  In this paper we present a protocol for the implementation of a
positive-operator-valued measure (POVM) on massive fermionic qubits. We present
methods for implementing non-dispersive qubit transport, spin rotations and
spin polarizing beam-splitter operations. Our scheme attains linear optics-like
control of the spatial extent of the qubits by considering groundstate
electrons trapped in the minima of surface acoustic waves in semiconductor
heterostructures. Furthermore, we numerically simulate a high-fidelity POVM
that carries out Procrustean entanglement distillation in the framework of our
scheme, using experimentally realistic potentials. Our protocol can be applied,
not only to pure ensembles with particle pairs of known identical entanglement,
but also to realistic ensembles of particle pairs with a distribution of
entanglement entropies. This paper provides an experimentally realisable design
for future quantum technologies.


title:
Investigating the Necessity of Distribution Markets in Accomodating High
  Penetration Microgrids

abstract:
  The increased need for reliable, resilient, and high quality power combined
with a falling cost of distributed generation technologies has resulted in a
rapid growth of microgrid in power systems. Although providing multitude of
benefits, the microgrid power transfer with the main grid, which is commonly
obtained using economy and reliability consideration, may result in major
operational drawbacks, most notably, a large mismatch between actual and
forecasted system loads. This paper investigates the impact of high penetration
microgrids on the power system net load, and further proposes three paradigms
that can be adopted to address the emerging operational issues. The IEEE 6-bus
test system is used for numerical studies and to further support the
discussions.


title: Banach spaces from a construction scheme

abstract:
  We construct a Banach space $\mathcal X_\varepsilon$ with an uncountable
$\varepsilon$-biorthogonal system but no uncountable $\tau$-biorthogonal system
for $\tau<\varepsilon$. In particular the space have no uncountable
biorthogonal system. We also construct a Banach space $\mathcal X_K$ with an
uncountable $K$-basic sequence but no uncountable $K'$-basic sequence, for
$1\leq K'<K$. A common feature of these examples is that they are both
constructed by recursive amalgamations using a single construction scheme.


title: A study on tuning parameter selection for the high-dimensional lasso

abstract:
  High-dimensional predictive models, those with more measurements than
observations, require regularization to be well defined, perform well
empirically, and possess theoretical guarantees. The amount of regularization,
often determined by tuning parameters, is integral to achieving good
performance. One can choose the tuning parameter in a variety of ways, such as
through resampling methods or generalized information criteria. However, the
theory supporting many regularized procedures relies on an estimate for the
variance parameter, which is complicated in high dimensions. We develop a suite
of information criteria for choosing the tuning parameter in lasso regression
by leveraging the literature on high-dimensional variance estimation. We derive
intuition showing that existing information-theoretic approaches work poorly in
this setting. We compare our risk estimators to existing methods with an
extensive simulation and derive some theoretical justification. We find that
our new estimators perform well across a wide range of simulation conditions
and evaluation criteria.


title:
Observation of pseudoscalar and tensor resonances in $J/\psi\rightarrow
  \gamma \phi \phi$

abstract:
  Based on a sample of $(1310.6 \pm 10.5) \times 10^{6}$ $J/\psi$ events
collected with the BESIII detector operating at the BEPCII storage ring, a
partial wave analysis of the decay $J/\psi\rightarrow \gamma \phi \phi$ is
performed in order to study the intermediate states. Results of the partial
wave analysis show that the structures are predominantly $0^{-+}$ states. The
existence of the $\eta(2225)$ is confirmed, and its resonance parameters are
measured. Two additional pseudoscalar states, the $\eta(2100)$ with a mass of
$2050_{-24}^{+30}{}_{-26}^{+75}$~MeV/$c^{2}$ and a width of
$250_{-30}^{+36}{}_{-164}^{+181}$~MeV/$c^{2}$ and the $X(2500)$ with a mass of
$2470_{-19}^{+15}{}_{-23}^{+101}$~MeV/$c^{2}$ and a width of
$230_{-35}^{+64}{}_{-33}^{+56}$~MeV/$c^{2}$, are observed. In addition to these
three pseudoscalar states, the scalar state $f_0(2100)$, and three tensor
states, the $f_2(2010)$, $f_2(2300)$ and $f_2(2340)$, are observed in the
process $J/\psi\rightarrow \gamma \phi\phi$. The product branching fractions
${\cal B}$($J/\psi\rightarrow \gamma X)\times{\cal B}(X\rightarrow \phi \phi)$
are reported.


title:
Galaxy Infall by Interacting with its Environment: a Comprehensive Study
  of 340 Galaxy Clusters

abstract:
  To study systematically the evolution on the angular extents of the galaxy,
ICM, and dark matter components in galaxy clusters, we compiled the optical and
X-ray properties of a sample of 340 clusters with redshifts $<0.5$, based on
all the available data with the Sloan Digital Sky Survey (SDSS) and {\it
Chandra}/{\it XMM-Newton}. For each cluster, the member galaxies were
determined primarily with photometric redshift measurements. The radial ICM
mass distribution, as well as the total gravitational mass distribution, were
derived from a spatially-resolved spectral analysis of the X-ray data. When
normalizing the radial profile of galaxy number to that of the ICM mass, the
relative curve was found to depend significantly on the cluster redshift; it
drops more steeply towards outside in lower redshift subsamples. The same
evolution is found in the galaxy-to-total mass profile, while the ICM-to-total
mass profile varies in an opposite way. We interpret that the galaxies, the
ICM, and the dark matter components had similar angular distributions when a
cluster was formed, while the galaxies travelling interior of the cluster have
continuously fallen towards the center relative to the other components, and
the ICM has slightly expanded relative to the dark matter although it suffers
strong radiative loss. This cosmological galaxy infall, accompanied by an ICM
expansion, can be explained by considering that the galaxies interact strongly
with the ICM while they are moving through it. The interaction is considered to
create a large energy flow of $10^{44-45}$ erg $\rm s^{-1}$ per cluster from
the member galaxies to their environment, which is expected to continue over
cosmological time scales.


title:
Temperature-field phase diagram of extreme magnetoresistance in
  lanthanum monopnictides

abstract:
  The recent discovery of extreme magnetoresistance in LaSb introduced
lanthanum monopnictides as a new platform to study topological semimetals
(TSMs). In this work we report the discovery of extreme magnetoresistance in
LaBi, confirming lanthanum monopnictides as a promising family of TSMs. These
binary compounds with the simple rock-salt structure are ideal model systems to
search for the origin of extreme magnetoresistance. Through a comparative study
of magnetotransport effects in LaBi and LaSb, we construct a triangular
temperature-field phase diagram that illustrates how a magnetic field tunes the
electronic behavior in these materials. We show that the triangular phase
diagram can be generalized to other topological semimetals with different
crystal structures and different chemical compositions. By comparing our
experimental results to band structure calculations, we suggest that extreme
magnetoresistance in LaBi and LaSb originates from a particular orbital texture
on their qasi-2D Fermi surfaces. The orbital texture, driven by spin-orbit
coupling, is likely to be a generic feature of various topological semimetals.


title:
Attosecond Transient Absorption in Dense Gases: Exploring the Interplay
  between Resonant Pulse Propagation and Laser-Induced Line Shape Control

abstract:
  We investigate the evolution of extreme ultraviolet (XUV) spectral lineshapes
in an optically-thick helium gas under near-infrared (IR) perturbation. In our
experimental and theoretical work, we systematically vary the IR intensity,
time-delay, gas density and IR polarization parameters to study lineshape
modifications induced by collective interactions, in a regime beyond the single
atom response of a thin, dilute gas. In both experiment and theory, we find
that specific features in the frequency-domain absorption profile, and their
evolution with propagation distance, can be attributed to the interplay between
resonant attosecond pulse propagation and IR induced phase shifts. Our
calculations show that this interplay also manifests itself in the time domain,
with the IR pulse influencing the reshaping of the XUV pulse propagating in the
resonant medium.


title:
From classical Lagrangians to Hamilton operators in the Standard-Model
  Extension

abstract:
  In this article we investigate whether a theory based on a classical
Lagrangian for the minimal Standard-Model Extension (SME) can be quantized such
that the result is equal to the corresponding low-energy Hamilton operator
obtained from the field-theory description. This analysis is carried out for
the whole collection of minimal Lagrangians found in the literature. The upshot
is that first quantization can be performed consistently. The unexpected
observation is made that at first order in Lorentz violation and at second
order in the velocity the Lagrangians are related to the Hamilton functions by
a simple transformation. Under mild assumptions, it is shown that this holds
universally. This result is used successfully to obtain classical Lagrangians
for two complicated sectors of the minimal SME that have not been considered in
the literature so far. Therefore, it will not be an obstacle anymore to derive
such Lagrangians even for involved sets of coefficients - at least to the level
of approximation stated above.


title: EIE: Efficient Inference Engine on Compressed Deep Neural Network

abstract:
  State-of-the-art deep neural networks (DNNs) have hundreds of millions of
connections and are both computationally and memory intensive, making them
difficult to deploy on embedded systems with limited hardware resources and
power budgets. While custom hardware helps the computation, fetching weights
from DRAM is two orders of magnitude more expensive than ALU operations, and
dominates the required power.
  Previously proposed 'Deep Compression' makes it possible to fit large DNNs
(AlexNet and VGGNet) fully in on-chip SRAM. This compression is achieved by
pruning the redundant connections and having multiple connections share the
same weight. We propose an energy efficient inference engine (EIE) that
performs inference on this compressed network model and accelerates the
resulting sparse matrix-vector multiplication with weight sharing. Going from
DRAM to SRAM gives EIE 120x energy saving; Exploiting sparsity saves 10x;
Weight sharing gives 8x; Skipping zero activations from ReLU saves another 3x.
Evaluated on nine DNN benchmarks, EIE is 189x and 13x faster when compared to
CPU and GPU implementations of the same DNN without compression. EIE has a
processing power of 102GOPS/s working directly on a compressed network,
corresponding to 3TOPS/s on an uncompressed network, and processes FC layers of
AlexNet at 1.88x10^4 frames/sec with a power dissipation of only 600mW. It is
24,000x and 3,400x more energy efficient than a CPU and GPU respectively.
Compared with DaDianNao, EIE has 2.9x, 19x and 3x better throughput, energy
efficiency and area efficiency.


title:
The parametric h-principle for minimal surfaces in $\mathbb R^n$ and
  null curves in $\mathbb C^n$

abstract:
  Let $M$ be an open Riemann surface. It was proved by Alarc\'on and
Forstneri\v{c} (arXiv:1408.5315) that every conformal minimal immersion
$M\to\mathbb R^3$ is isotopic to the real part of a holomorphic null curve
$M\to\mathbb C^3$. In this paper, we prove the following much stronger result
in this direction: for any $n\geq 3$, the inclusion $\iota$ of the space of
real parts of nonflat null holomorphic immersions $M\to\mathbb C^n$ into the
space of nonflat conformal minimal immersions $M\to \mathbb R^n$ satisfies the
parametric h-principle with approximation; in particular, it is a weak homotopy
equivalence. We prove analogous results for several other related maps, and we
describe the homotopy type of the space of all holomorphic immersions
$M\to\mathbb C^n$. For an open Riemann surface $M$ of finite topological type,
we obtain optimal results by showing that $\iota$ and several related maps are
inclusions of strong deformation retracts; in particular, they are homotopy
equivalences.


title: Randomness Extraction in AC0 and with Small Locality

abstract:
  Randomness extractors, which extract high quality (almost-uniform) random
bits from biased random sources, are important objects both in theory and in
practice. While there have been significant progress in obtaining near optimal
constructions of randomness extractors in various settings, the computational
complexity of randomness extractors is still much less studied. In particular,
it is not clear whether randomness extractors with good parameters can be
computed in several interesting complexity classes that are much weaker than P.
  In this paper we study randomness extractors in the following two models of
computation: (1) constant-depth circuits (AC0), and (2) the local computation
model. Previous work in these models, such as [Vio05a], [GVW15] and [BG13],
only achieve constructions with weak parameters. In this work we give explicit
constructions of randomness extractors with much better parameters. As an
application, we use our AC0 extractors to study pseudorandom generators in AC0,
and show that we can construct both cryptographic pseudorandom generators
(under reasonable computational assumptions) and unconditional pseudorandom
generators for space bounded computation with very good parameters.
  Our constructions combine several previous techniques in randomness
extractors, as well as introduce new techniques to reduce or preserve the
complexity of extractors, which may be of independent interest. These include
(1) a general way to reduce the error of strong seeded extractors while
preserving the AC0 property and small locality, and (2) a seeded randomness
condenser with small locality.


title:
On Li-Yau gradient estimate for sum of squares of vector fields up to
  higher step

abstract:
  In this paper, we generalize the Cao-Yau's gradient estimate for the sum of
squares of vector fields up to higher step under assumption of the generalized
curvature-dimension inequality. With its applications, by deriving a
curvature-dimension inequality, we are able to obtain the Li-Yau gradient
estimate for the CR heat equation in a closed pseudohermitian manifold of
nonvanishing torsion tensors. As consequences, we obtain the Harnack inequality
and upper bound estimate for the CR heat kernel.


title:
Optimal Transport Theory for Power-Efficient Deployment of Unmanned
  Aerial Vehicles

abstract:
  In this paper, the optimal deployment of multiple unmanned aerial vehicles
(UAVs) acting as flying base stations is investigated. Considering the downlink
scenario, the goal is to minimize the total required transmit power of UAVs
while satisfying the users' rate requirements. To this end, the optimal
locations of UAVs as well as the cell boundaries of their coverage areas are
determined. To find those optimal parameters, the problem is divided into two
sub-problems that are solved iteratively. In the first sub-problem, given the
cell boundaries corresponding to each UAV, the optimal locations of the UAVs
are derived using the facility location framework. In the second sub-problem,
the locations of UAVs are assumed to be fixed, and the optimal cell boundaries
are obtained using tools from optimal transport theory. The analytical results
show that the total required transmit power is significantly reduced by
determining the optimal coverage areas for UAVs. These results also show that,
moving the UAVs based on users' distribution, and adjusting their altitudes can
lead to a minimum power consumption. Finally, it is shown that the proposed
deployment approach, can improve the system's power efficiency by a factor of
20 compared to the classical Voronoi cell association technique with fixed UAVs
locations.


title: Reduced twisted crossed products over C*-simple groups

abstract:
  We consider reduced crossed products of twisted C*-dynamical systems over
C*-simple groups. We prove there is a bijective correspondence between maximal
ideals of the reduced crossed product and maximal invariant ideals of the
underlying C*-algebra, and a bijective correspondence between tracial states on
the reduced crossed product and invariant tracial states on the underlying
C*-algebra. In particular, the reduced crossed product is simple if and only if
the underlying C*-algebra has no proper non-trivial invariant ideals, and the
reduced crossed product has a unique tracial state if and only if the
underlying C*-algebra has a unique invariant tracial state. We also show that
the reduced crossed product satisfies an averaging property analogous to
Powers' averaging property.


title:
High density NV sensing surface created via He^(+) ion implantation of
  (12)^C diamond

abstract:
  We present a promising method for creating high-density ensembles of
nitrogen-vacancy centers with narrow spin-resonances for high-sensitivity
magnetic imaging. Practically, narrow spin-resonance linewidths substantially
reduce the optical and RF power requirements for ensemble-based sensing. The
method combines isotope purified diamond growth, in situ nitrogen doping, and
helium ion implantation to realize a 100 nm-thick sensing surface. The obtained
10^(17) cm^(-3) nitrogen-vacancy density is only a factor of 10 less than the
highest densities reported to date, with an observed spin resonance linewidth
over 10 times more narrow. The 200 kHz linewidth is most likely limited by
dipolar broadening indicating even further reduction of the linewidth is
desirable and possible.


title:
Equisingular resolution with SNC fibers and combinatorial type of
  varieties

abstract:
  We introduce the notion of combinatorial type of varieties $X$ which
generalizes the concept of the dual complex of SNC divisors. It is a unique, up
to homotopy, finite simplicial complex $\Sigma(X)$ which is functorial with
respect to morphisms of varieties. Its cohomology $H^i(\Sigma(X),Q)$ for
complex projective varieties coincide with weight zero part of the Deligne
filtration $W_0(H^i(X,Q))$. The notion can be understood as a topological
measure of the singularities of algebaric schemes of finite type. We also prove
that any variety in characteristic zero admits the Hironaka desingularization
with all fibers having SNC. Moreover the dual complexes of the fibers are
isomorphic on strata. Also for any morphism $f:X\to Y$ there exists a similar
desingularization $\tilde{X}\to X$ for which the induce morphism $\tilde{X}\to
Y$ has SNC fibers. One of the consequence is that for any projective morphism
$f:X\to Y$ the combinatorial type of the fiber is a constructible function. In
particular $\dim(W_0H^i(f^{-1}(y))$ is constructible.


title: Recent ATLAS results and preparations for Run 2

abstract:
  The CERN LHC delivered 25/fb of proton-proton collision data in 2011-2012 at
sqrt{s} = 7 - 8 TeV centre-of-mass energy to the ATLAS detector. These Run 1
data were used to discover the Higgs boson and measure its properties as well
as to perform numerous other tests of the Standard Model via precision
measurements and searches for New Physics. In preparation for the Run 2 data
taking at sqrt{s} = 13 TeV, the collaboration embarked on an upgrade program
during the long LHC machine shutdown in 2013-2015. The early 2015 data set was
then used to promptly recommission the apparatus allowing the first physics
results to appear already in the summer of 2015. After briefly reviewing the
upgrade and the improved performance of the detector, this paper concentrates
on the final Run~1 results on Higgs, W and Z boson, electroweak multi-boson and
top quark production as well as on searches for supersymmetry and other new
phenomena.


title: TopCom: Index for Shortest Distance Query in Directed Graph

abstract:
  Finding shortest distance between two vertices in a graph is an important
problem due to its numerous applications in diverse domains, including
geo-spatial databases, social network analysis, and information retrieval.
Classical algorithms (such as, Dijkstra) solve this problem in polynomial time,
but these algorithms cannot provide real-time response for a large number of
bursty queries on a large graph. So, indexing based solutions that pre-process
the graph for efficiently answering (exactly or approximately) a large number
of distance queries in real-time is becoming increasingly popular. Existing
solutions have varying performance in terms of index size, index building time,
query time, and accuracy. In this work, we propose T OP C OM , a novel
indexing-based solution for exactly answering distance queries. Our experiments
with two of the existing state-of-the-art methods (IS-Label and TreeMap) show
the superiority of T OP C OM over these two methods considering scalability and
query time. Besides, indexing of T OP C OM exploits the DAG (directed acyclic
graph) structure in the graph, which makes it significantly faster than the
existing methods if the SCCs (strongly connected component) of the input graph
are relatively small.


title:
Spatial imaging of the movement of bound atoms to reveal the Rydberg
  molecular bond via electromagnetically induced transparency

abstract:
  We propose an approach to detect individual Rydberg molecules with each
molecule consisting of two atoms in different Rydberg states. The scheme
exploits the movement of atoms in the presence of an external force that exerts
only on atoms in one Rydberg state. Since the movement of atoms in the other
Rydberg state depends on whether they are bound with atoms directly driven by
the applied force, bound atoms can be distinguished from unbound atoms. By
utilizing electromagnetically induced transparency, it is possible to
non-destructively image the positions of molecules. The scheme is sensitive to
a weak force, which is suited to optically detect spatial positions and bond
structure of Rydberg molecules.


title:
Efficient thermoelectric materials using nonmagnetic double perovskites
  with $d^0$/$d^6$ band filling

abstract:
  Efficient thermoelectric materials should present large Seebeck coefficient,
high electrical conductivity and low thermal conductivity. An enhanced Seebeck
coefficient can be obtained from materials where the Fermi level can be aligned
with a large and narrow peak of the density of states, particularly when a
substantial band valley degeneracy occurs. A high electrical conductivity comes
as a consequence of large conductive hopping paths between the atoms of the
material. Both physical quantities can be decoupled and optimized independently
if their origins can be ascribed to different sets of bands. Based on these
assumptions, double perovskites A$_2$BB'O$_6$ with $d^0/d^6$ filling for the B
and B' metal cations, respectively, have been considered. They provide a
desirable band structure with degenerate B-$t_{2g}$ / B'-$e_g$ bands above the
Fermi level together with a low thermal conductivity. We have carried out
first-principles simulations for various of these nonmagnetic double
perovskites and showed that all of them present a large Seebeck coefficient
(consequence of the localized and empty $t_{2g}$ states of the B-cation), and
large electrical conductivity due to the more spread unoccupied $e_{g}$ band of
the B' cation. We have seen that if they can be optimally doped, they could
show a figure of merit comparable or even higher than the best $n$-type
thermoelectric oxides, such as SrTiO$_{3}$. Different mechanisms to tune the
band structure and enhance the thermoelectric figure of merit are explored,
including epitaxial strain, hydrostatic pressure, chemical pressure, and
external doping. A fully relaxed structure has also been studied, showing that
a realistic calculation is necessary to make accurate predictions, but also
proving that the main trends shown throughout the paper remain unchanged.


title: Optimal Transport for Seismic Full Waveform Inversion

abstract:
  Full waveform inversion is a successful procedure for determining properties
of the earth from surface measurements in seismology. This inverse problem is
solved by a PDE constrained optimization where unknown coefficients in a
computed wavefield are adjusted to minimize the mismatch with the measured
data. We propose using the Wasserstein metric, which is related to optimal
transport, for measuring this mismatch. Several advantageous properties are
proved with regards to convexity of the objective function and robustness with
respect to noise. The Wasserstein metric is computed by solving a Monge-Ampere
equation. We describe an algorithm for computing its Frechet gradient for use
in the optimization. Numerical examples are given.


title: Fundamental Limits in Multi-image Alignment

abstract:
  The performance of multi-image alignment, bringing different images into one
coordinate system, is critical in many applications with varied signal-to-noise
ratio (SNR) conditions. A great amount of effort is being invested into
developing methods to solve this problem. Several important questions thus
arise, including: Which are the fundamental limits in multi-image alignment
performance? Does having access to more images improve the alignment?
Theoretical bounds provide a fundamental benchmark to compare methods and can
help establish whether improvements can be made. In this work, we tackle the
problem of finding the performance limits in image registration when multiple
shifted and noisy observations are available. We derive and analyze the
Cram\'er-Rao and Ziv-Zakai lower bounds under different statistical models for
the underlying image. The accuracy of the derived bounds is experimentally
assessed through a comparison to the maximum likelihood estimator. We show the
existence of different behavior zones depending on the difficulty level of the
problem, given by the SNR conditions of the input images. We find that
increasing the number of images is only useful below a certain SNR threshold,
above which the pairwise MLE estimation proves to be optimal. The analysis we
present here brings further insight into the fundamental limitations of the
multi-image alignment problem.


title: Cosmetic banding on knots and links

abstract:
  We present various examples of cosmetic bandings on knots and links, that is,
bandings on knots and links leaving their types unchanged. As a byproduct, we
give a hyperbolic knot which admits exotic chirally cosmetic surgeries yielding
hyperbolic manifolds. This gives a counterexample to a conjecture raised by
Bleiler, Hodgson and Weeks.