title: Structures in supercritical scale-free percolation

abstract:
  Scale-free percolation is a percolation model on $\mathbb{Z}^d$ which can be
used to model real-world networks. We prove bounds for the graph distance in
the regime where vertices have infinite degrees. We fully characterize
transience vs. recurrence for dimension 1 and 2 and give sufficient conditions
for transience in dimension 3 and higher. Finally, we show the existence of a
hierarchical structure for parameters where vertices have degrees with infinite
variance and obtain bounds on the cluster density.


title:
H\"older continuous densities of solutions of SDEs with measurable and
  path dependent drift coefficients

abstract:
  We consider a process given as the solution of a one-dimensional stochastic
differential equation with irregular, path dependent and time-inhomogeneous
drift coefficient and additive noise. H\"older continuity of the Lebesgue
density of that process at any given time is achieved using a different
approach than the classical ones in the literature. Namely, the H\"older
regularity of the densities is obtained via a control problem by identifying
the stochastic differential equation with the worst global H\"older constant.
Then we generalise our findings to a larger class of diffusion coefficients.
The novelty of this method is that it is not based on a variational calculus
and it is suitable for non-Markovian processes.


title:
Unsupervised Classification in Hyperspectral Imagery with Nonlocal Total
  Variation and Primal-Dual Hybrid Gradient Algorithm

abstract:
  In this paper, a graph-based nonlocal total variation method (NLTV) is
proposed for unsupervised classification of hyperspectral images (HSI). The
variational problem is solved by the primal-dual hybrid gradient (PDHG)
algorithm. By squaring the labeling function and using a stable simplex
clustering routine, an unsupervised clustering method with random
initialization can be implemented. The effectiveness of this proposed algorithm
is illustrated on both synthetic and real-world HSI, and numerical results show
that the proposed algorithm outperforms other standard unsupervised clustering
methods such as spherical K-means, nonnegative matrix factorization (NMF), and
the graph-based Merriman-Bence-Osher (MBO) scheme.


title:
Primal-dual method for searching equillibriums in mixed traffic
  assignment problems

abstract:
  We consider mixed model of traffic flow distribution in large networks (BMW
model, 1954 & Stable Dynamic model, 1999). We build dual problem and consider
primal-dual mirror descent method for the dual problem. There are two ways to
recover the solution of the primal problem. First technique is based on
"models" approach and second one is based on Lagrange multiplyers technique.
Both approaches have its own advantages and drawbacks. We discuss them.


title: Elucidating Dicke Superradiance by quantum uncertainty

abstract:
  Recently it was shown in Ref. [Phys. Rev. Lett. 112, 140402 (2014)] that in
the idealized Dicke model of superradiance there is no entanglement among any
partitions of the system during the total evolution time of the system. This
result immediately conducts us to question if other measures from quantum
information theory can explain the characteristic release of energy in a short
time interval. In this work we identify the uncertainty of purely quantum
origin as the property responsible for Dicke superradiance. The quantum
uncertainty on the population of each emitter of the sample captured by the
Wigner-Yanase skew information (WYSI) is proportional to the correlation
radiation rate, which is the part of the total radiated power coming from
dipole correlations and responsible for releasing in a short time a great
intensity of radiation energy. We also show that the correlation measure called
local quantum uncertainty, which is the minimization of the WYSI over all local
observables, presents a double sudden change induced by environment. The time
window between these two sudden changes is used to define the interval in which
symmetric global observables of the system behave classically for $N
\rightarrow \infty$, although the emitters remain strongly quantum correlated.


title: Resonant TMR inversion in LiF/EuS based spin-filter tunnel junctions

abstract:
  Resonant tunneling can lead to inverse tunnel magnetoresistance when impurity
levels rather than direct tunneling dominate the transport process. We
fabricated hybrid magnetic tunnel junctions of CoFe/LiF/EuS/Ti, with an
epitaxial LiF energy barrier joined with a polycrystalline EuS spin-filter
bar-rier. Due to the water solubility of LiF, the devices were fully packaged
in situ. The devices showed sizeable positive TMR up to 16% at low bias
voltages but clearly inverted TMR at higher bias voltages. The TMR inversion
depends sensitively on the thickness of LiF, and the tendency of inversion
disap-pears when LiF gets thick enough and recovers its intrinsic properties.


title:
Spin- and Symmetry-Filtering Combined Tunnel Magnetoresistance through
  Epitaxial MgO/EuS Tunnel Barriers

abstract:
  We created epitaxial magnetic tunnel junctions of FeCo/MgO/EuS on MgO
buffered Si (100). Tunnel magnetoresistance reached up to 64% at 4.2 K. An
unexpected fast drop of magnetoresistance was recorded for MgO thickness above
1 nm, which is attributed to the forced nonspecular conductance across the EuS
conduction band minimum located at the X point, rather than the desired Delta_1
conductance centered around the Gamma point.


title: Nuclear Matrix Elements for Tests of Local Lorentz Invariance Violation

abstract:
  The nuclear matrix elements for the momentum quadrupole operator are
important for the interpretation of precision atomic physics experiments that
search for violations of local Lorentz and CPT symmetry and for new
spin-dependent forces. We use the configuration-interaction nuclear shell model
and self-consistent mean field theory to calculate these matrix elements in
$^{21}$Ne, $^{23}$Na, $^{131}$Xe, $^{173}$Yb and $^{201}$Hg. These are the
first microscopic calculations of the nuclear matrix elements for the momentum
quadrupole tensor that go beyond the single-particle estimate. We show that
they are strongly suppressed by the many-body correlations, in contrast to the
well known enhancement of the spatial quadrupole nuclear matrix elements.


title:
Stability of the Matrix Dyson Equation and Random Matrices with
  Correlations

abstract:
  We consider real symmetric or complex hermitian random matrices with
correlated entries. We prove local laws for the resolvent and universality of
the local eigenvalue statistics in the bulk of the spectrum. The correlations
have fast decay but are otherwise of general form. The key novelty is the
detailed stability analysis of the corresponding matrix valued Dyson equation
whose solution is the deterministic limit of the resolvent.


title: Integrating Storage to Power System Management

abstract:
  Wind integration in power grids is very difficult, essentially because of the
uncertain nature of wind speed. Forecasting errors on output from wind turbines
may have costly consequences. For instance, power might be bought at highest
price to meet the load. On the other hand, in case of surplus, power may be
wasted. Energy storage facility may provide some recourse against the
uncertainty on wind generation. Because of the sequential nature of power
scheduling problems, stochastic dynamic programming is often used as solution
method. However, this scheme is limited to very small networks by the so-called
curse of dimensionality. To face such limitations, several approximate
approaches have been proposed. We analyze the management of a network composed
of conventional power units as well as wind turbines through approximate
dynamic programming. We consider a general power network model with ramping
constraints on the conventional generators. We use generalized linear
programming techniques to linearize the problems. We test the algorithm on
several networks of different sizes and report results about the computation
time. We also carry out comparisons with classical dynamic programming on a
small network. The results show the algorithm seems to offer a fair trade-off
between solution time and accuracy.


title:
The replica symmetric solution for Orthogonally Constrained Heisenberg
  Model on Bethe lattice

abstract:
  In this paper, we study the thermodynamic properties of a system of
$D$-components classical Heisenberg spins lying on the vertices of a random
regular graph, with an unconventional first neighbor non-random interaction
$J(\mathbf{S}_i\cdot \mathbf{S}_k)^2$. We can consider this model as a
continuum version of anti-ferromagnetic $D$-states Potts model. We compute the
paramagnetic free energy, using a new approach, presented in this paper for the
first time, based on the replica method. Through the linear stability analysis,
we obtain an instability line on the temperature-connectivity plane that
provides a bound to the appearance of a phase transition. We also argue about
the character of the instability observed.


title: Modeling Single-Peakedness for Votes with Ties

abstract:
  Single-peakedness is one of the most important and well-known domain
restrictions on preferences. The computational study of single-peaked
electorates has largely been restricted to elections with tie-free votes, and
recent work that studies the computational complexity of manipulative attacks
for single-peaked elections for votes with ties has been restricted to
nonstandard models of single-peaked preferences for top orders. We study the
computational complexity of manipulation for votes with ties for the standard
model of single-peaked preferences and for single-plateaued preferences. We
show that these models avoid the anomalous complexity behavior exhibited by the
other models. We also state a surprising result on the relation between the
societal axis and the complexity of manipulation for single-peaked preferences.


title: Space-Efficient Error Reduction for Unitary Quantum Computations

abstract:
  This paper develops general space-efficient methods for error reduction for
unitary quantum computation. Consider a polynomial-time quantum computation
with completeness $c$ and soundness $s$, either with or without a witness
(corresponding to QMA and BQP, respectively). To convert this computation into
a new computation with error at most $2^{-p}$, the most space-efficient method
known requires extra workspace of ${O \bigl( p \log \frac{1}{c-s} \bigr)}$
qubits. This space requirement is too large for scenarios like
logarithmic-space quantum computations. This paper presents error-reduction
methods for unitary quantum computations (i.e., computations without
intermediate measurements) that require extra workspace of just ${O \bigl( \log
\frac{p}{c-s} \bigr)}$ qubits. This in particular gives the first methods of
strong amplification for logarithmic-space unitary quantum computations with
two-sided bounded error. This also leads to a number of consequences in
complexity theory, such as the uselessness of quantum witnesses in
bounded-error logarithmic-space unitary quantum computations, the PSPACE upper
bound for QMA with exponentially-small completeness-soundness gap, and strong
amplification for matchgate computations.


title: Discrete Transformation of Baryon- and Lepton-Nonconserving Processes

abstract:
  We consider discrete transformations ($C, P, T$ and $CP$) of baryon- and
lepton-nonconserving processes. It has long been thought that values ($\pm 1,
\pm i$) form the correct set of fermionic arbitrary phases for discrete
transformations. In this paper we show that this idea is not generally true. In
order to count the number of fundamental fermions in a process, $F$ number has
been introduced. According to our evaluation for any operator which breaks
$B-L$ symmetry and violate $F$ number the set of values ($\pm 1, \pm i$) is not
the correct set of fermionic arbitrary phases, due to the fact that discrete
transformations of such operators will change by altering the fermionic phases
from $\pm 1$ to $\pm i$.


title:
Primal-dual mirror descent for the stochastic programming problems with
  functional constraints

abstract:
  We propose primal-dual stochastic mirror descent for the convex optimization
problems with functional constraints. We obtain the rate of convergence in
terms of probability of large deviations.


title: Evaluating Theta Derivatives with Rational Characteristics

abstract:
  We evaluate 35 different theta derivatives with rational characteristics
using the method of Matsuda, in which the logarithmic derivatives at $z=0$ of
the triple product expansions of the associated theta functions become linear
combinations of known theta series of weight 1.


title: Sum rules for interaction of $\Upsilon$ resonances with $Z_b \pi$

abstract:
  The strength of the amplitudes for the coupling between the bottomonium
$\Upsilon(nS)$ states, the bottomonium-like isovector resonances $Z_b$ and a
pion, $\Upsilon(nS) Z_b \pi$, is considered. These amplitudes describe the
decays $Z_b \to \Upsilon(nS) \pi$ for $n=1,\,2,\,3$, and the processes
$\Upsilon(nS) \to Z_b \pi$ for $n=5,\,6, \ldots$ with either $Z_b(10610)$ or
$Z_b(10650)$. It is pointed out that analyticity and unitarity impose a sum
rule for these couplings to each of the $Z_b$ resonances. With the currently
available data it appears to be difficult or impossible to simultaneously
satisfy the sum rules for the $Z_b(10610)$ and $Z_b(10650)$ resonances. This
difficulty can be resolved if there is a considerable dissimilarity in the
yield of the states $Z_b(10610) \pi$ and $Z_b(10650) \pi$ in the $e^+e^-$
annihilation at energies above the $\Upsilon(5S)$ resonance.


title: Ancilla dimension in quantum channel discrimination

abstract:
  Single-shot quantum channel discrimination is a fundamental task in quantum
information theory. It is well known that entanglement with an ancillary system
can help in this task, and furthermore that an ancilla with the same dimension
as the input of the channels is always sufficient for optimal discrimination of
two channels. A natural question to ask is whether the same holds true for the
output dimension. That is, in cases when the output dimension of the channels
is (possibly much) smaller than the input dimension, is an ancilla with
dimension equal to the output dimension always sufficient for optimal
discrimination? We show that the answer to this question is "no" by
construction of a family of counterexamples. This family contains instances
with arbitrary finite gap between the input and output dimensions, and still
has the property that in every case, for optimal discrimination, it is
necessary to use an ancilla with dimension equal to that of the input.
  The proof relies on a characterization of all operators on the trace norm
unit sphere that maximize entanglement negativity. In the case of density
operators we generalize this characterization to a broad class of entanglement
measures, which we call weak entanglement measures. This characterization
allows us to conclude that a quantum channel is reversible if and only if it
preserves entanglement as measured by any weak entanglement measure, with the
structure of maximally entangled states being equivalent to the structure of
reversible maps via the Choi isomorphism. We also include alternate proofs of
other known characterizations of channel reversibility.


title: Drive the Dirac Electrons into Cooper Pairs in SrxBi2Se3

abstract:
  Topological superconductor is a very interesting and frontier topic in
condensed matter physics1. Despite the tremendous efforts in exploring the
topological superconductivity, its presence is however still under heavy
debates. The Dirac electrons are supposed to exist in a thin layer of the
surface of a topological insulator. Due to the finite spin-orbital coupling,
these electrons will have a spin-momentum locking effect. In this case, the
superfluid with the spin singlet Cooper pairing is not completely comforted by
the Dirac electrons. It thus remains unclear whether and how the Dirac
electrons fall into Cooper pairing in an intrinsic superconductor with the
topological surface states. In this work, we show the systematic study of
scanning tunneling microscope/spectroscopy on the possible topological
superconductor SrxBi2Se3. We first show that only the intercalated (or
inserted), not the substituted Sr atoms can induce superconductivity. Then we
show the full superconducting gaps without any abnormal in-gap density of
states as expected theoretically for the bulk topological superconductivity.
However, we find that the surface Dirac electrons will simultaneously condense
into the superconducting state when the energy is smaller than the bulk
superconducting gap. This vividly demonstrates how the surface Dirac electrons
are driven into Cooper pairs.


title: Kinematical uniqueness of homogeneous isotropic LQC

abstract:
  In a paper by Ashtekar and Campiglia, invariance under volume preserving
residual diffeomorphisms has been used to single out the standard
representation of the reduced holonomy-flux algebra in homogeneous loop quantum
cosmology (LQC). In this paper, we use invariance under all residual
diffeomorphisms to single out the standard kinematical Hilbert space of
homogeneous isotropic LQC for both the standard configuration space
$\mathbb{R}_{\mathrm{Bohr}}$, as well as for the Fleischhack one $\mathbb{R}
\sqcup \mathbb{R}_{\mathrm{Bohr}}$. We first determine the scale invariant
Radon measures on these spaces, and then show that the Haar measure on
$\mathbb{R}_{\mathrm{Bohr}}$ is the only such measure for which the momentum
operator is hermitian w.r.t. the corresponding inner product. In particular,
the measure is forced to be identically zero on $\mathbb{R}$ in the Fleischhack
case, so that for both approaches, the standard kinematical LQC-Hilbert space
is singled out.


title:
Ground-based gamma-ray telescopes as ground stations in deep-space
  lasercom

abstract:
  As the amount of information to be transmitted from deep-space rapidly
increases, the radiofrequency technology has become a bottleneck in space
communications. RF is already limiting the scientific outcome of deep-space
missions and could be a significant obstacle in the developing of manned
missions. Lasercom holds the promise to solve this problem, as it will
considerably increase the data rate while decreasing the energy, mass and
volume of onboard communication systems. In RF deep-space communications, where
the received power is the main limitation, the traditional approach to boost
the data throughput has been increasing the receiver's aperture, e.g. the 70-m
antennas in the NASA's Deep Space Network. Optical communications also can
benefit from this strategy, thus 10-m class telescopes have typically been
suggested to support future deep-space links. However, the cost of big
telescopes increase exponentially with their aperture, and new ideas are needed
to optimize this ratio. Here, the use of ground-based gamma-ray telescopes,
known as Cherenkov telescopes, is suggested. These are optical telescopes
designed to maximize the receiver's aperture at a minimum cost with some
relaxed requirements. As they are used in an array configuration and multiple
identical units need to be built, each element of the telescope is designed to
minimize its cost. Furthermore, the native array configuration would facilitate
the joint operation of Cherenkov and lasercom telescopes. These telescopes
offer very big apertures, ranging from several meters to almost 30 meters,
which could greatly improve the performance of optical ground stations. The key
elements of these telescopes have been studied applied to lasercom, reaching
the conclusion that it could be an interesting strategy to include them in the
future development of an optical deep-space network.


title: Interpretable Deep Neural Networks for Single-Trial EEG Classification

abstract:
  Background: In cognitive neuroscience the potential of Deep Neural Networks
(DNNs) for solving complex classification tasks is yet to be fully exploited.
The most limiting factor is that DNNs as notorious 'black boxes' do not provide
insight into neurophysiological phenomena underlying a decision. Layer-wise
Relevance Propagation (LRP) has been introduced as a novel method to explain
individual network decisions. New Method: We propose the application of DNNs
with LRP for the first time for EEG data analysis. Through LRP the single-trial
DNN decisions are transformed into heatmaps indicating each data point's
relevance for the outcome of the decision. Results: DNN achieves classification
accuracies comparable to those of CSP-LDA. In subjects with low performance
subject-to-subject transfer of trained DNNs can improve the results. The
single-trial LRP heatmaps reveal neurophysiologically plausible patterns,
resembling CSP-derived scalp maps. Critically, while CSP patterns represent
class-wise aggregated information, LRP heatmaps pinpoint neural patterns to
single time points in single trials. Comparison with Existing Method(s): We
compare the classification performance of DNNs to that of linear CSP-LDA on two
data sets related to motor-imaginery BCI. Conclusion: We have demonstrated that
DNN is a powerful non-linear tool for EEG analysis. With LRP a new quality of
high-resolution assessment of neural activity can be reached. LRP is a
potential remedy for the lack of interpretability of DNNs that has limited
their utility in neuroscientific applications. The extreme specificity of the
LRP-derived heatmaps opens up new avenues for investigating neural activity
underlying complex perception or decision-related processes.


title: Amodal Instance Segmentation

abstract:
  We consider the problem of amodal instance segmentation, the objective of
which is to predict the region encompassing both visible and occluded parts of
each object. Thus far, the lack of publicly available amodal segmentation
annotations has stymied the development of amodal segmentation methods. In this
paper, we sidestep this issue by relying solely on standard modal instance
segmentation annotations to train our model. The result is a new method for
amodal instance segmentation, which represents the first such method to the
best of our knowledge. We demonstrate the proposed method's effectiveness both
qualitatively and quantitatively.


title: Black hole thermodynamics, conformal couplings, and R^2 terms

abstract:
  Lovelock theory provides a tractable model of higher-curvature gravity in
which several questions can be studied analytically. This is the reason why, in
the last years, this theory has become the favorite arena to study the effects
of higher-curvature terms in the context of AdS/CFT correspondence. Lovelock
theory also admits extensions that permit to accommodate matter coupled to
gravity in a non-minimal way. In this setup, problems such as the backreaction
of matter on the black hole geometry can also be solved exactly. In this paper,
we study the thermodynamics of black holes in theories of gravity of this type,
which include both higher-curvature terms, U(1) gauge fields, and conformal
couplings with matter fields in D dimensions. These charged black hole
solutions exhibit a backreacting scalar field configuration that is regular
everywhere outside and on the horizon, and may exist both in asymptotically
flat and asymptotically Anti-de Sitter (AdS) spaces. We work out explicitly the
boundary action for this theory, which renders the variational problem
well-posed and suffices to regularize the Euclidean action in AdS. We also
discuss several interrelated properties of the theory, such as its duality
symmetry under field redefinition and how it acts on black holes and
gravitational wave solutions.


title: The 999th Swift gamma-ray burst: Some like it thermal

abstract:
  We present a multiwavelength study of GRB 151027A. This is the 999th GRB
detected by the Swift satellite and it has a densely sampled emission in the
X-ray and optical band and has been observed and detected in the radio up to
140 days after the prompt. The multiwavelength light curve from 500 s to 140
days can be modelled through a standard forward shock afterglow but requires an
additional component to reproduce the early X-ray and optical emission. We
present TNG and LBT optical observations performed 19.6, 33.9 and 92.3 days
after the trigger which show a bump with respect to a standard afterglow flux
decay and are possibly interpreted as due to the underlying SN and host galaxy
(of 0.4 uJy in the R band). Radio observations, performed with SRT, Medicina,
EVN and VLBA between day 4 and 140, suggest that the burst exploded in an
environment characterised by a density profile scaling with the distance from
the source (wind profile). A remarkable feature of the prompt emission is the
presence of a bright flare 100 s after the trigger, lasting 70 seconds in the
soft X-ray band, which was simultaneously detected from the optical band up to
the MeV energy range. By combining Swift-BAT/XRT and Fermi-GBM data, the
broadband (0.3-1000 keV) time resolved spectral analysis of the flare reveals
the coexistence of a non-thermal (power law) and thermal blackbody components.
The BB component contributes up to 35% of the luminosity in the 0.3-1000 keV
band. The gamma-ray emission observed in Swift-BAT and Fermi-GBM anticipates
and lasts less than the soft X-ray emission as observed by Swift-XRT, arguing
against a Comptonization origin. The BB component could either be produced by
an outflow becoming transparent or by the collision of a fast shell with a
slow, heavy and optically thick fireball ejected during the quiescent time
interval between the initial and later flares of the burst.


title:
Zooming in on major mergers: dense, starbursting gas in cosmological
  simulations

abstract:
  We introduce the `Illustris zoom simulation project', which allows the study
of selected galaxies forming in the $\Lambda$CDM cosmology with a 40 times
better mass resolution than in the parent large-scale hydrodynamical Illustris
simulation. We here focus on the starburst properties of the gas in four
cosmological simulations of major mergers. The galaxies in our high-resolution
zoom runs exhibit a bursty mode of star formation with gas consumption
timescales 10 times shorter than for the normal star formation mode. The strong
bursts are only present in the simulations with the highest resolution, hinting
that a too low resolution is the reason why the original Illustris simulation
showed a dearth of starburst galaxies. Very pronounced bursts of star formation
occur in two out of four major mergers we study. The high star formation rates,
the short gas consumption timescales and the morphology of these systems
strongly resemble observed nuclear starbursts. This is the first time that a
sample of major mergers is studied through self-consistent cosmological
hydrodynamical simulations instead of using isolated galaxy models setup on a
collision course. We also study the orbits of the colliding galaxies and find
that the starbursting gas preferentially appears in head-on mergers with very
high collision velocities. Encounters with large impact parameters do typically
not lead to the formation of starbursting gas.


title: On the Detectability of Light Dark Matter with Superfluid Helium

abstract:
  We show that a two-excitation process in superfluid helium, combined with
sensitivity to meV energy depositions, can probe dark matter down to the ~keV
warm dark matter mass limit. This mass reach is three orders of magnitude below
what can be probed with ordinary nuclear recoils in helium at the same energy
resolution. For dark matter lighter than $\sim 100$ keV, the kinematics of the
process requires the two athermal excitations to have nearly equal and opposite
momentum, potentially providing a built-in coincidence mechanism for
controlling backgrounds.

categories: hep-ph astro-ph.CO cond-mat.other hep-th


title:
Host-Galaxy Properties of 32 Low-Redshift Superluminous Supernovae from
  the Palomar Transient Factory

abstract:
  We present ultraviolet through near-infrared photometry and spectroscopy of
the host galaxies of all superluminous supernovae (SLSNe) discovered by the
Palomar Transient Factory prior to 2013, and derive measurements of their
luminosities, star-formation rates, stellar masses, and gas-phase
metallicities. We find that Type I (hydrogen-poor) SLSNe are found almost
exclusively in low-mass (M < 2x10^9 M_sun) and metal-poor (12+log[O/H] < 8.4)
galaxies. We compare the mass and metallicity distributions of our sample to
nearby galaxy catalogs in detail and conclude that the rate of SLSNe-I as a
fraction of all SNe is heavily suppressed in galaxies with metallicities >0.5
Z_sun. Extremely low metallicities are not required, and indeed provide no
further increase in the relative SLSN rate. Several SLSN-I hosts are undergoing
vigorous starbursts, but this may simply be a side effect of metallicity
dependence: dwarf galaxies tend to have bursty star-formation histories.
Type-II (hydrogen-rich) SLSNe are found over the entire range of galaxy masses
and metallicities, and their integrated properties do not suggest a strong
preference for (or against) low-mass/low-metallicity galaxies. Two hosts
exhibit unusual properties: PTF 10uhf is a Type I SLSN in a massive, luminous
infrared galaxy at redshift z=0.29, while PTF 10tpz is a Type II SLSN located
in the nucleus of an early-type host at z=0.04.


title:
The LyA-LyC Connection: Evidence for an Enhanced Contribution of
  UV-faint Galaxies to Cosmic Reionization

abstract:
  The escape of ionizing Lyman Continuum (LyC) photons requires the existence
of low-N_HI sightlines, which also promote escape of Lyman-Alpha (Lya). We use
a suite of 2500 Lya Monte-Carlo radiative transfer simulations through models
of dusty, clumpy interstellar (`multiphase') media from Gronke & Dijkstra
(2016), and compare the escape fractions of Lya [f_esc(Lya)] and LyC radiation
[f_esc(LyC)]. We find that f_esc(LyC) and f_esc(Lya) are correlated: galaxies
with a low f_esc(Lya) consistently have a low f_esc(LyC), while galaxies with a
high f_esc(Lya) exhibit a large dispersion in f_esc(LyC). We argue that there
is increasing observational evidence that Lya escapes more easily from UV-faint
galaxies. The correlation between f_esc(LyC) and f_esc(Lya) then implies that
UV-faint galaxies contribute more to the ionizing background than implied by
the faint-end slope of the UV-luminosity function. In multiphase gases, the
ionizing escape fraction is most strongly affected by the cloud covering
factor, f_cl, which implies that f_esc(LyC) is closely connected to the
observed Lya spectral line shape. Specifically, LyC emitting galaxies typically
having narrower, more symmetric line profiles. This prediction is qualitatively
similar to that for `shell models'.


title: Conformal Higher Spin Theory and Twistor Space Actions

abstract:
  We consider the twistor description of conformal higher spin theories and
give twistor space actions for the self-dual sector of theories with spin
greater than two that produce the correct flat space-time spectrum. We identify
a ghost-free subsector, analogous to the embedding of Einstein gravity with
cosmological constant in Weyl gravity, which generates the unique spin-s
three-point anti-MHV amplitude consistent with Poincare invariance and helicity
constraints. By including interactions between the infinite tower of
higher-spin fields we give a geometric interpretation to the twistor equations
of motion as the integrability condition for a holomorphic structure on an
infinite jet bundle. Finally, we introduce anti-self-dual interaction terms to
define a twistor action for the full conformal higher spin theory.


title:
A Distant Echo of Milky Way Central Activity closes the Galaxy's Baryon
  Census

abstract:
  We report on the presence of large amounts of million-degree gas in the Milky
Way's interstellar and circum-galactic medium. This gas (1) permeates both the
Galactic plane and the halo, (2) extends to distances larger than 60-200 kpc
from the center, and (3) its mass is sufficient to close the Galaxy's baryon
census.
  Moreover, we show that a vast, $\sim 6$ kpc radius, spherically-symmetric
central region of the Milky Way above and below the 0.16 kpc thick plane, has
either been emptied of hot gas or the density of this gas within the cavity has
a peculiar profile, increasing from the center up to a radius of $\sim 6$ kpc,
and then decreasing with a typical halo density profile. This, and several
other converging pieces of evidence, suggest that the current surface of the
cavity, at 6 kpc from the Galaxy's center, traces the distant echo of a period
of strong nuclear activity of our super-massive black-hole, occurred about 6
Myrs ago.


title: Twin Baryogenesis

abstract:
  In the context of Twin Higgs models, we study a simple mechanism that
simultaneously generates asymmetries in the dark and visible sector through the
out-of-equilibrium decay of a TeV scale particle charged under a combination of
baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin
baryon, which is easy to achieve because of the similarity between the two
confinement scales. Dark matter is metastable and can decay to three quarks,
yielding indirect detection signatures. The mechanism requires the introduction
of a new colored particle, typically within the reach of the LHC, of which we
study the rich collider phenomenology, including prompt and displaced dijets,
multi-jets, monojets and monotops.


title: All-loop correlators of integrable $\lambda$-deformed $\sigma$-models

abstract:
  We compute the 2- and 3-point functions of currents and primary fields of
$\lambda$-deformed integrable $\sigma$-models characterized also by an integer
$k$. Our results apply for any semisimple group $G$, for all values of the
deformation parameter $\lambda$ and up to order $1/k$. We deduce the OPEs and
equal-time commutators of all currents and primaries. We derive the currents'
Poisson brackets which assume Rajeev's deformation of the canonical structure
of the isotropic PCM, the underlying structure of the integrable
$\lambda$-deformed $\sigma$-models. We also present analogous results in two
limiting cases of special interest, namely for the non-Abelian T-dual of the
PCM and for the pseudodual model.


title: Leptogenesis and gravity: baryon asymmetry without decays

abstract:
  A popular class of theories attributes the matter-antimatter asymmetry of the
Universe to CP-violating decays of super-heavy BSM particles in the Early
Universe. Recently, we discovered a new source of leptogenesis in these models,
namely that the same Yukawa phases which provide the CP violation for decays,
combined with curved-spacetime loop effects, lead to an entirely new
gravitational mechanism for generating an asymmetry, driven by the expansion of
the Universe and independent of the departure of the heavy particles from
equilibrium. In this Letter, we build on previous work by analysing the full
Boltzmann equation, exploring the full parameter space of the theory and
studying the time-evolution of the asymmetry. Remarkably, we find regions of
parameter space where decays play no part at all, and where the baryon
asymmetry of the Universe is determined solely by gravitational effects.


title:
Spherical accretion: the influence of inner boundary and quasi-periodic
  oscillations

abstract:
  Bondi accretion assumes that there is a sink of mass at the center -- which
in case of a black hole (BH) corresponds to the advection of matter across the
event horizon. Other stars, such as a neutron star (NS), have surfaces and
hence the infalling matter has to slow down at the surface. We study the
initial value problem in which the matter distribution is uniform and at rest
at $t=0$. We consider different inner boundary conditions for BHs and NSs:
outflow boundary condition (mimicking mass sink at the center) valid for BHs;
and {\em reflective} and steady-shock (allowing gas to cross the inner boundary
at subsonic speeds) boundary conditions for NSs. We also obtain a similarity
solution for cold accretion on to BHs and NSs. 1-D simulations show the
formation of an outward propagating and a standing shock in NSs for reflective
and steady-shock boundary conditions, respectively. Entropy is the highest at
the bottom of the subsonic region for reflective boundary conditions. In 2-D
this profile is convectively unstable. Using steady-shock inner boundary
conditions, the flow is unstable to the standing accretion shock instability
(SASI) in 2-D, which leads to global shock oscillations and may be responsible
for quasi-periodic oscillations (QPOs) seen in the lightcurves of accreting
systems. For steady accretion in the quiescent state, spherical accretion rate
on to a NS can be suppressed by orders of magnitude compared to that on to a
BH.


title:
Galaxy-scale gravitational lens candidates from the Hyper Suprime-Cam
  imaging survey and the Galaxy And Mass Assembly spectroscopic survey

abstract:
  We present a list of galaxy-scale lens candidates including a highly probable
interacting galaxy-scale lens in the Hyper Suprime-Cam (HSC) imaging survey. We
combine HSC imaging with the blended-spectra catalog from the Galaxy And Mass
Assembly (GAMA) survey to identify lens candidates, and use lens mass modeling
to confirm the candidates. We find 46 matches between the HSC S14A_0b imaging
data release and the GAMA catalog. Ten of them are probable lens systems
according to their morphology and redshifts. There is one system with an
interacting galaxy pair, HSC J084928+000949, that has a valid mass model. We
predict the total mass enclosed by the Einstein radius of $\sim0.72$"
($\sim1.65$kpc) for this new expected lens system to be
$\sim10^{10.59}M_{\odot}$. Using the photometry in the {\it grizy} bands of the
HSC survey and stellar population synthesis modeling with a Salpeter stellar
initial mass function, we estimate the stellar mass within the Einstein radius
to be $\sim10^{10.46}\,M_{\odot}$. We thus find a dark matter mass fraction
within the Einstein radius of $\sim25\%$. Further spectroscopy or
high-resolution imaging would allow confirmation of the nature of these lens
candidates. The particular system with the interacting galaxy pair, if
confirmed, would provide an opportunity to study the interplay between dark
matter and stars as galaxies build up through hierarchical mergers.


title: Dynamical Mordell-Lang and Automorphisms of Blow-ups

abstract:
  We show that if $\phi : X \to X$ is an automorphism of a smooth projective
variety and $D \subset X$ is an irreducible divisor for which the set of $d$ in
$D$ with $\phi^n(d)$ in $D$ for some nonzero $n$ is not Zariski dense, then
$(X, \phi)$ admits an equivariant rational fibration to a curve. As a
consequence, we show that certain blowups (e.g. blowups in high codimension) do
not alter the finiteness of $\textrm{Aut}(X)$, extending results of
Bayraktar-Cantat. We also generalize results of Arnol'd on the growth of
multiplicities of the intersection of a variety with the iterates of some other
variety under an automorphism.
  These results follow from a non-reduced analogue of the dynamical
Mordell-Lang conjecture. Namely, let $\phi : X \to X$ be an \'etale
endomorphism of a smooth projective variety $X$ over a field $k$ of
characteristic zero. We show that if $Y$ and $Z$ are two closed subschemes of
$X$, then the set $A_\phi(Y,Z) = \{n : \phi^n(Y) \subseteq Z\}$ is the union of
a finite set and finitely many residue classes, whose modulus is bounded in
terms of the geometry of $Y$.


title:
Entanglement Conservation, ER=EPR, and a New Classical Area Theorem for
  Wormholes

abstract:
  We consider the question of entanglement conservation in the context of the
ER=EPR correspondence equating quantum entanglement with wormholes. In quantum
mechanics, the entanglement between a system and its complement is conserved
under unitary operations that act independently on each; ER=EPR suggests that
an analogous statement should hold for wormholes. We accordingly prove a new
area theorem in general relativity: for a collection of dynamical wormholes and
black holes in a spacetime satisfying the null curvature condition, the maximin
area for a subset of the horizons (giving the largest area attained by the
minimal cross section of the multi-wormhole throat separating the subset from
its complement) is invariant under classical time evolution along the outermost
apparent horizons. The evolution can be completely general, including horizon
mergers and the addition of classical matter satisfying the null energy
condition. This theorem is the gravitational dual of entanglement conservation
and thus constitutes an explicit characterization of the ER=EPR duality in the
classical limit.


title:
Clustering, Cosmology and a New Era of Black Hole Demographics -- I. The
  Conditional Luminosity Function of Active Galactic Nuclei

abstract:
  Deep X-ray surveys have provided a comprehensive and largely unbiased view of
active galactic nuclei (AGN) evolution stretching back to $z \sim 5$. However,
it has been challenging to use the survey results to connect this evolution to
the cosmological environment that AGNs inhabit. Exploring this connection will
be crucial to understanding the triggering mechanisms of AGNs and how these
processes manifest in observations at all wavelengths. In anticipation of
upcoming wide-field X-ray surveys that will allow quantitative analysis of AGN
environments, this paper presents a method to observationally constrain the
Conditional Luminosity Function (CLF) of AGNs at a specific $z$. Once measured,
the CLF allows the calculation of the AGN bias, mean dark matter halo mass, AGN
lifetime, halo occupation number, and AGN correlation function -- all as a
function of luminosity. The CLF can be constrained using a measurement of the
X-ray luminosity function and the correlation length at different luminosities.
The method is illustrated at $z \approx 0$ and $0.9$ using the limited data
that is currently available, and a clear luminosity dependence in the AGN bias
and mean halo mass is predicted at both $z$, supporting the idea that there are
at least two different modes of AGN triggering. In addition, the CLF predicts
that $z\approx 0.9$ quasars may be commonly hosted by haloes with
$M_{\mathrm{h}} \sim 10^{14}$ M$_{\odot}$. These `young cluster' environments
may provide the necessary interactions between gas-rich galaxies to fuel
luminous accretion. The results derived from this method will be useful to
populate AGNs of different luminosities in cosmological simulations.


title:
Clustering, Cosmology and a New Era of Black Hole Demographics -- II.
  The Conditional Luminosity Functions of Type 2 and Type 1 Active Galactic
  Nuclei

abstract:
  The orientation-based unification model of active galactic nuclei (AGNs)
posits that the principle difference between obscured (Type 2) and unobscured
(Type 1) AGNs is the line-of-sight into the central engine. If this model is
correct than there should be no difference in many of the properties of AGN
host galaxies (e.g., the mass of the surrounding dark matter haloes). However,
recent clustering analyses of Type 1 and Type 2 AGNs have provided some
evidence for a difference in the halo mass, in conflict with the
orientation-based unified model. In this work, a method to compute the
Conditional Luminosity Function (CLF) of Type 2 and Type 1 AGNs is presented.
The CLF allows many fundamental halo properties to be computed as a function of
AGN luminosity, which we apply to the question of the host halo masses of Type
1 and 2 AGNs. By making use of the total AGN CLF, the Type 1 X-ray luminosity
function, and the luminosity-dependent Type 2 AGN fraction, the CLFs of Type 1
and 2 AGNs are calculated at $z\approx 0$ and $0.9$. At both $z$, there is no
statistically significant difference in the mean halo mass of Type 2 and 1 AGNs
at any luminosity. There is marginal evidence that Type 1 AGNs may have larger
halo masses than Type 2s, which would be consistent with an evolutionary
picture where quasars are initially obscured and then subsequently reveal
themselves as Type 1s. As the Type 1 lifetime is longer, the host halo will
increase somewhat in mass during the Type 1 phase. The CLF technique will be a
powerful way to study the properties of many AGNs subsets (e.g., radio-loud,
Compton-thick) as future wide-area X-ray and optical surveys substantially
increase our ability to place AGNs in their cosmological context.


title: Diving deeper into mentee networks

abstract:
  Modern computer vision is all about the possession of powerful image
representations. Deeper and deeper convolutional neural networks have been
built using larger and larger datasets and are made publicly available. A large
swath of computer vision scientists use these pre-trained networks with varying
degrees of successes in various tasks. Even though there is tremendous success
in copying these networks, the representational space is not learnt from the
target dataset in a traditional manner. One of the reasons for opting to use a
pre-trained network over a network learnt from scratch is that small datasets
provide less supervision and require meticulous regularization, smaller and
careful tweaking of learning rates to even achieve stable learning without
weight explosion. It is often the case that large deep networks are not
portable, which necessitates the ability to learn mid-sized networks from
scratch.
  In this article, we dive deeper into training these mid-sized networks on
small datasets from scratch by drawing additional supervision from a large
pre-trained network. Such learning also provides better generalization
accuracies than networks trained with common regularization techniques such as
l2, l1 and dropouts. We show that features learnt thus, are more general than
those learnt independently. We studied various characteristics of such networks
and found some interesting behaviors.


title: A $L_\mu - L_\tau$ theory of Higgs flavor violation and $(g-2)_\mu$

abstract:
  Several experiments reported hints for the violation of lepton flavor or
lepton flavor universality in processes involving muons. Most prominently,
there is the hint for a non-zero rate of the flavor violating Higgs decay $h
\to \tau\mu$ at the LHC, as well as the hint for lepton flavor universality
violation in rare $B$ meson decays at LHCb. In addition, also the long standing
discrepancy in the anomalous magnetic moment of the muon motivates new physics
connected to muons. A symmetry which violates lepton flavor universality, is
$L_\mu-L_\tau$: the difference of muon-number and tau-number. We show that
adding vector-like fermions to a $L_\mu-L_\tau$ theory generates naturally an
effect in the anomalous magnetic moment of the muon and $h\to\tau\mu$, while
effects in other $\tau \to \mu$ transitions are systematically suppressed by
symmetry arguments. We find that if $L_\mu-L_\tau$ is gauged it is possible to
also accommodate the discrepant $b\to s\mu\mu$ data while predicting a
$\tau\to3\mu$ and a modified $h\to\mu\mu$ rate within reach of upcoming
experiments.


title: Phases of N=2 Necklace Quivers

abstract:
  We classify the phases of N=2 elliptic models in terms of their global
properties i.e. the spectrum of line operators. We show the agreement between
the field theory and the M-theory analysis and how the phases form orbits under
the action of the S-duality group which corresponds to the mapping class group
of the Riemann surface in M-theory.


title: The hot gas content of fossil galaxy clusters

abstract:
  We investigate the properties of the hot gas in four fossil galaxy systems
detected at high significance in the Planck Sunyaev-Zeldovich (SZ) survey.
XMM-Newton observations reveal overall temperatures of kT ~ 5-6 keV and yield
hydrostatic masses M500,HE > 3.5 x 10e14 Msun, confirming their nature as bona
fide massive clusters. We measure the thermodynamic properties of the hot gas
in X-rays (out to beyond R500 in three cases) and derive their individual
pressure profiles out to R ~ 2.5 R500 with the SZ data. We combine the X-ray
and SZ data to measure hydrostatic mass profiles and to examine the hot gas
content and its radial distribution. The average Navarro-Frenk-White (NFW)
concentration parameter, c500 = 3.2 +/- 0.4, is the same as that of relaxed
`normal' clusters. The gas mass fraction profiles exhibit striking variation in
the inner regions, but converge to approximately the cosmic baryon fraction
(corrected for depletion) at R500. Beyond R500 the gas mass fraction profiles
again diverge, which we interpret as being due to a difference in gas clumping
and/or a breakdown of hydrostatic equilibrium in the external regions. Overall
our observations point to considerable radial variation in the hot gas content
and in the gas clumping and/or hydrostatic equilibrium properties in these
fossil clusters, at odds with the interpretation of their being old, evolved
and undisturbed. At least some fossil objects appear to be dynamically young.


title:
Utility maximization problem with random endowment and transaction
  costs: when wealth may become negative

abstract:
  In this paper we study the problem of maximizing expected utility from the
terminal wealth with proportional transaction costs and random endowment. In
the context of the existence of consistent price systems, we consider the
duality between the primal utility maximization problem and the dual one, which
is set up on the domain of finitely additive measures. In particular, we prove
duality results for utility functions supporting possibly negative values.
Moreover, we construct the shadow market by the dual optimal process and
consider the utility based pricing for random endowment.


title: Topological surface states in dense solid hydrogen

abstract:
  It has recently been established that two-dimensional massless graphene-like
systems and three-dimensional line-node topological semimetals comprise a
special class of centrosymmetric materials where edge/surface states of
topological nature inevitably appear in some k-regions. We show that the phases
of solid hydrogen produced at megabar pressures can be line-node topological
semimetals. In such phases, the material exhibits topological surface states
and therefore can be a poor bulk metal but good surface conductor. The results
may help to explain discrepant high-pressure experimental data reported for
dense hydrogen as well as provide predictions for future measurements,
including possible surface superconductivity in hydrogen. Related topological
behavior may be expected in high-pressure phases formed in other elements
including simple metals.


title: Influence of Agents Heterogeneity in Cellular Model of Evacuation

abstract:
  The influence of agents heterogeneity on the microscopic characteristics of
pedestrian flow is studied via an evacuation simulation tool based on the
Floor-Field model. The heterogeneity is introduced in agents velocity,
aggressiveness, and sensitivity to occupation. The simulation results are
compared to data gathered during an original experiment. The comparison shows
that the heterogeneity in aggressiveness and sensitivity occupation enables to
reproduce some microscopic aspects. The heterogeneity in velocity seems to be
redundant.


title:
On sets of first-order formulas axiomatizing representable relation
  algebras

abstract:
  This is the author's 2004 Master's thesis at Iowa State University, done
under the supervision of Roger D. Maddux. It provides a background in relation
algebras. Three results from the literature are demonstrated in full: (i.) RRA
is a variety. (ii.) RRA is not finitely based. (iii.) Any equational basis for
RRA has infinitely many variables. We also give an elementary proof of
Birkoff's variety theorem.


title:
Fermi arcs and their topological character in the candidate type-II Weyl
  semimetal MoTe2

abstract:
  We report a combined experimental and theoretical study of the candidate
type-II Weyl semimetal MoTe2. Using laser-based angle-resolved photoemission we
resolve multiple distinct Fermi arcs on the inequivalent top and bottom (001)
surfaces. All surface states observed experimentally are reproduced by an
electronic structure calculation for the experimental crystal structure that
predicts a topological Weyl semimetal state with 8 type-II Weyl points. We
further use systematic electronic structure calculations simulating different
Weyl point arrangements to discuss the robustness of the identified Weyl
semimetal state and the topological character of Fermi arcs in MoTe2.


title: Propositional Abduction with Implicit Hitting Sets

abstract:
  Logic-based abduction finds important applications in artificial intelligence
and related areas. One application example is in finding explanations for
observed phenomena. Propositional abduction is a restriction of abduction to
the propositional domain, and complexity-wise is in the second level of the
polynomial hierarchy. Recent work has shown that exploiting implicit hitting
sets and propositional satisfiability (SAT) solvers provides an efficient
approach for propositional abduction. This paper investigates this earlier work
and proposes a number of algorithmic improvements. These improvements are shown
to yield exponential reductions in the number of SAT solver calls. More
importantly, the experimental results show significant performance improvements
compared to the the best approaches for propositional abduction.


title: Flexible Fractional Repetition Codes for Distributed Storage Networks

abstract:
  Consider the following fundamental question of distributed storage networks:
Given any arbitrary $(n,k,d)$ values, whether there exists an intelligent
helper selection scheme (assuming unlimited memory and computing power) that
can strictly improve the storage-bandwidth (S-B) tradeoff. Ahmad et al. 18'
answered this question by proving that for a subset of $(n,k,d)$ values, no
helper selection scheme can ever improve the S-B tradeoff, and for the
$(n,k,d)$ not in that subset, a new scheme called family helper selection (FHS)
can strictly improve the S-B tradeoff over a blind helper selection scheme.
Nonetheless, the analysis of FHS is done by a min-cut analysis with no actual
code construction.
  This work fills this gap between pure min-cut analysis and actual code
construction by pairing FHS with a new, generalized version of the existing
fractional repetition (FR) codes. Specifically, existing FR codes are
exact-repair codes that admit the highly-desirable repair-by-transfer property,
but its unique construction limits the application to a restricted set of
$(n,k,d)$ values. In contrast, our new construction, termed flexible fractional
repetition codes, can be applied to arbitrary $(n,k,d)$ while retaining most of
the practical benefits of FR codes, i.e., admitting small repair bandwidth,
being exact-repair, and being almost repairable-by-transfer.


title:
When Can Helper Node Selection Improve Regenerating Codes? Part I:
  Graph-Based Analysis

abstract:
  Regenerating codes (RCs) can significantly reduce the repair-bandwidth of
distributed storage networks. Initially, the analysis of RCs was based on the
assumption that during the repair process, the newcomer does not distinguish
(among all surviving nodes) which nodes to access, i.e., the newcomer is
oblivious to the set of helpers being used. Such a scheme is termed the blind
helper selection (BHS) scheme. Nonetheless, it is intuitive in practice that
the newcomer should choose to access only those "good" helpers. In this
two-part paper, a new characterization of the effect of choosing the helper
nodes in terms of the storage-bandwidth tradeoff is given. Specifically, the
answer to the following fundamental question is provided: Under what condition
does proactively choosing the helper nodes improve the storage-bandwidth
tradeoff?
  Through a graph-based analysis, this Part I paper answers this question by
providing a necessary and sufficient condition under which optimally choosing
good helpers strictly improves the storage-bandwidth tradeoff. A low-complexity
helper selection solution, termed the family helper selection (FHS) scheme, is
proposed and the corresponding storage/repair-bandwidth curve is characterized.
This Part I paper also proves that under some design parameters, the FHS scheme
is indeed optimal among all helper selection schemes. In the Part II paper, an
explicit construction of an exact-repair code is proposed that achieves the
minimum-bandwidth-regenerating (MBR) point of the FHS scheme. The new
exact-repair code can be viewed as a generalization of the existing fractional
repetition code.


title: How to "Censor" a Black Hole Singularity and Beyond

abstract:
  We argue that a black hole can be viewed as a gravitational optical element
that images its interior onto the horizon. Being diffraction limited the "Airy
hyper-ball" that forms as a result of interference of gravitational waves, does
not allow for infinite resolution. Thereby, effectively censoring the geodetic
singularity. The mechanism proposed must imply intrinsic angular momentum as in
the Kerr black hole solution. However, assuming that a static black hole
develops from an initial Kerr solution the destroyed hyperball is delegated to
the horizon by the principle of increasing entropy. This lost information about
the system resolution is now packed on the horizon, which in effect provides
the censorship. Should the mechanism be applicable to the early universe, we
suggest that the low variance circles seen in the CMB sky are traces of such an
interference pattern.


title:
Simple and Accurate Oscillation Probabilities for Three Coupled
  Neutrinos Propagating in Matter

abstract:
  Within a conventional Hamiltonian description, we find accurate closed-form
expressions for the oscillation probabilities of three coupled neutrinos
propagating in matter. Subtle cancelations that occur in coefficients of our
formulation are avoided for all transitions $\nu_a \to \nu_b$ by transforming
to a different set of coefficients presented in an appendix of this paper. The
neutrino mass eigenvalues are easily obtained numerically as the solution of a
cubic equation. Our methods are illustrated for flavor-changing transitions in
the $(\nu_e,\nu_\mu)$ sector. The resulting analytic expressions oscillation
probabilities, which are particularly simple, are also accurate to a few
percent over all regions of interest at present and the envisioned future
neutrino facilities. While somewhat less accurate than numerical simulations,
our approximate expressions are sufficiently accuracy to obviate the need for
exact computer simulations in many circumstances.


title:
Polynomial-Time Algorithms for Energy Games with Special Weight
  Structures

abstract:
  Energy games belong to a class of turn-based two-player infinite-duration
games}played on a weighted directed graph. It is one of the rare and intriguing
combinatorial problems that lie in ${\sf NP} \cap {\sf co\mbox{-}NP}$, but are
not known to be in ${\sf P}$. The existence of polynomial-time algorithms has
been a major open problem for decades and apart from pseudopolynomial
algorithms there is no algorithm that solves any non-trivial subclass in
polynomial time.
  In this paper, we give several results based on the weight structures of the
graph. First, we identify a notion of penalty and present a polynomial-time
algorithm when the penalty is large. Our algorithm is the first polynomial-time
algorithm on a large class of weighted graphs. It includes several worst-case
instances on which previous algorithms, such as value iteration and random
facet algorithms, require at least sub-exponential time. Our main technique is
developing the first non-trivial approximation algorithm and showing how to
convert it to an exact algorithm. Moreover, we show that in a practical case in
verification where weights are clustered around a constant number of values,
the energy game problem can be solved in polynomial time. We also show that the
problem is still as hard as in general when the clique-width is bounded or the
graph is strongly ergodic, suggesting that restricting the graph structure does
not necessarily help.


title:
Your Neighbors Are My Spies: Location and other Privacy Concerns in
  GLBT-focused Location-based Dating Applications

abstract:
  Trilateration is one of the well-known threat models to the user's location
privacy in location-based apps, especially those contain highly sensitive
information such as dating apps. The threat model mainly bases on the publicly
shown distance from a targeted victim to the adversary to pinpoint the victim's
location. As a countermeasure, most of location-based apps have already
implemented the 'hide distance' function, or added noise to the publicly shown
distance in order to protect their user's location privacy. The effectiveness
of such approaches however is still questionable.


title: A vase of catenoids

abstract:
  In this note we construct a vase of catenoids - a symmetric immersed minimal
surface with planar and catenoid ends.


title: Decision Making and Productivity Measurement

abstract:
  In this article, the concepts of technical efficiency, efficiency,
effectiveness and productivity are illustrated. It is discussed that when firms
are not homogenous, the situation is the same as when each factor has a
different unit of measurement from one firm to another, and there-fore, no
meaningful discrimination can be expressed, unless a set of known weights are
introduced to standardize data. A linear programming DEA model is used when a
set of known weights are given to calculate the technical efficiency and
efficiency of a set of homogenous DMUs with multiple input factors and output
factors. A numerical example is also provided.


title: Combined Preheating on the lattice with applications to Higgs inflation

abstract:
  We use classical lattice simulations in 3+1 dimensions to study the interplay
between the resonant production of particles during preheating and the
subsequent decay of these into a set of secondary species. We choose to work in
a simplified version of Higgs inflation in which the Higgs field non-minimally
coupled to gravity plays the role of the inflaton. Our numerical results extend
the analytical estimates in the literature beyond the linear regime and shed
some light on the limitations of the analytical techniques. The inclusion of
fast and inefficient decays postpones the onset of parametric resonance by
depleting the particles produced at the bottom of the potential. In spite of
this delay, fermions are shown to play an important role on the destruction of
the inflaton field. The limitations of our approach and its applications to a
realistic Higgs inflation scenario are also discussed.


title:
A Collaborative Untethered Virtual Reality Environment for Interactive
  Social Network Visualization

abstract:
  The increasing prevalence of Virtual Reality technologies as a platform for
gaming and video playback warrants research into how to best apply the current
state of the art to challenges in data visualization. Many current VR systems
are noncollaborative, while data analysis and visualization is often a
multi-person process. Our goal in this paper is to address the technical and
user experience challenges that arise when creating VR environments for
collaborative data visualization. We focus on the integration of multiple
tracking systems and the new interaction paradigms that this integration can
enable, along with visual design considerations that apply specifically to
collaborative network visualization in virtual reality. We demonstrate a system
for collaborative interaction with large 3D layouts of Twitter friend/follow
networks. The system is built by combining a 'Holojam' architecture (multiple
GearVR Headsets within an OptiTrack motion capture stage) and Perception Neuron
motion suits, to offer an untethered, full-room multi-person visualization
experience.


title: Unfolded Seiberg-Witten Floer spectra, I: Definition and invariance

abstract:
  Let $Y$ be a closed and oriented $3$-manifold. We define different versions
of unfolded Seiberg-Witten Floer spectra for $Y$. These invariants generalize
Manolescu's Seiberg-Witten Floer spectrum for rational homology $3$-spheres. We
also compute some examples when $Y$ is a Seifert space.


title: Automatic Sequences and Curves over Finite Fields

abstract:
  We prove that if $y=\sum_{n=0}^\infty{\bf a}(n)x^n\in\mathbb{F}_q[[x]]$ is an
algebraic power series of degree $d$, height $h$, and genus $g$, then the
sequence ${\bf a}$ is generated by an automaton with at most $q^{h+d+g-1}$
states, up to a vanishingly small error term. This is a significant improvement
on previously known bounds. Our approach follows an idea of David Speyer to
connect automata theory with algebraic geometry by representing the transitions
in an automaton as twisted Cartier operators on the differentials of a curve.


title: The IBM 2016 English Conversational Telephone Speech Recognition System

abstract:
  We describe a collection of acoustic and language modeling techniques that
lowered the word error rate of our English conversational telephone LVCSR
system to a record 6.6% on the Switchboard subset of the Hub5 2000 evaluation
testset. On the acoustic side, we use a score fusion of three strong models:
recurrent nets with maxout activations, very deep convolutional nets with 3x3
kernels, and bidirectional long short-term memory nets which operate on FMLLR
and i-vector features. On the language modeling side, we use an updated model
"M" and hierarchical neural network LMs.


title: Cloudrone: Micro Clouds in the Sky

abstract:
  Recent years have witnessed several initiatives on enabling Internet access
to the next three billion people. Access to the Internet necessarily translates
to access to its services. This means that the goal of providing Internet
access requires ac- cess to its critical service infrastructure, which are
currently hosted in the cloud. However, recent works have pointed out that the
current cloud centric nature of the Internet is a fundamental barrier for
Internet access in rural/remote areas as well as in developing regions. It is
important to explore (low cost) solutions such as micro cloud infrastructures
that can provide services at the edge of the network (potentially on demand),
right near the users. In this paper, we present Cloudrone- a preliminary idea
of deploying a lightweight micro cloud infrastructure in the sky using
indigenously built low cost drones, single board computers and lightweight
Operating System virtualization technologies. Our paper lays out the
preliminary ideas on such a system that can be instantaneously deployed on
demand. We describe an initial design of the Cloudrone and provide a
preliminary evaluation of the proposed system mainly focussed on the
scalability issues of supporting multiple services and users.


title:
Cosmological Galaxy Evolution with Superbubble Feedback II: The Limits
  of Supernovae

abstract:
  We explore when supernovae can (and cannot) regulate the star formation and
bulge growth in galaxies based on a sample of 18 simulated galaxies. The
simulations include key physics such as evaporation and conduction, neglected
in prior work, and required to correctly model superbubbles resulting from
stellar feedback. We show that for galaxies with virial masses
$>10^{12}\;M_\odot$, supernovae alone cannot prevent excessive star formation.
This failure occurs due to a shutdown of galactic winds, with wind mass
loadings falling from $\eta\sim10$ to $\eta<1$. In more massive systems, this
transfer of baryons to the circumgalactic medium falters earlier on and the
galaxies diverge significantly from observed galaxy scaling relations and
morphologies. The decreasing efficiency is simply due to a deepening potential
well preventing gas escape. This implies that non-supernova feedback mechanisms
must become dominant for galaxies with stellar masses greater than
$\sim4\times10^{10}\;M_\odot$. The runaway growth of the central stellar bulge,
strongly linked to black hole growth, suggests that feedback from active
galactic nuclei is the probable mechanism. Below this mass, supernovae alone
are able to produce a realistic stellar mass fraction, star formation history
and disc morphology.


title: Text writing in the air

abstract:
  This paper presents a real time video based pointing method which allows
sketching and writing of English text over air in front of mobile camera.
Proposed method have two main tasks: first it track the colored finger tip in
the video frames and then apply English OCR over plotted images in order to
recognize the written characters. Moreover, proposed method provides a natural
human-system interaction in such way that it do not require keypad, stylus, pen
or glove etc for character input. For the experiments, we have developed an
application using OpenCv with JAVA language. We tested the proposed method on
Samsung Galaxy3 android mobile. Results show that proposed algorithm gains the
average accuracy of 92.083% when tested for different shaped alphabets. Here,
more than 3000 different Magnetic 3D shaped characters were used [Ref:
http://learnrnd.com/news.php?id=Magnetic_3D_Bio_Printing]. Our proposed system
is the software based approach and relevantly very simple, fast and easy. It
does not require sensors or any hardware rather than camera and red tape.
Moreover, proposed methodology can be applicable for all disconnected languages
but having one issue that it is color sensitive in such a way that existence of
any red color in the background before starting the character writing can lead
to false results.


title:
Abnormality Detection in Correlated Gaussian Molecular Nano-Networks:
  Design and Analysis

abstract:
  A nano abnormality detection scheme (NADS) in molecular nano-networks is
studied. This is motivated by the fact that early detection of diseases such as
cancer play a crucial role in their successful treatment. The proposed NADS is
in fact a two-tier network of sensor nano-machines (SNMs) in the first tier and
a data-gathering node (DGN) at the sink. The SNMs detect the presence of
competitor cells (abnormality) by variations in input and/or parameters of a
nano-communications channel (NCC). The noise of SNMs as their nature suggest is
considered correlated in time and space and herein assumed additive Gaussian.
In the second step, the SNMs transmit micro-scale messages over a noisy micro
communications channel (MCC) to the DGN, where a decision is made upon fusing
the received signals. We find an optimum design of detectors for each of the
NADS tiers based on the end-to-end NADS performance. The detection performance
of each SNM is analyzed by setting up a generalized likelihood ratio test.
Next, taking into account the effect of the MCC, the overall performance of the
NADS is analyzed in terms of probabilities of misdetection and false alarm. In
addition, computationally efficient expressions to quantify the NADS
performance is derived by providing respectively an approximation and an upper
bound for the probabilities of misdetection and false alarm. This in turn
enables formulating a design problem, where the optimized concentration of SNMs
in a sample is obtained for a high probability of detection and a limited
probability of false alarm. The results indicate that otherwise ignoring the
spatial and temporal correlation of SNM noise in the analysis, leads to an NADS
that noticeably underperforms in operations.


title:
The mass function method for obtaining exact solutions of Einstein
  equations

abstract:
  We show that the mass function method makes it much easier to obtain the
exact solutions of Einstein equations. The known solutions for empty space and
for the universe filled with dust-like matter are considered from the point of
view of the method and new exact solutions are obtained. Generalized solutions
for the Schwarzschild type black holes are considered. It is shown that such
black holes always contain non-baryonic matter. New exact solution for the
black hole embedded into dust matter cosmological background is obtained.


title: Infinitary $\lambda$-Calculi from a Linear Perspective (Long Version)

abstract:
  We introduce a linear infinitary $\lambda$-calculus, called
$\ell\Lambda_{\infty}$, in which two exponential modalities are available, the
first one being the usual, finitary one, the other being the only construct
interpreted coinductively. The obtained calculus embeds the infinitary
applicative $\lambda$-calculus and is universal for computations over infinite
strings. What is particularly interesting about $\ell\Lambda_{\infty}$, is that
the refinement induced by linear logic allows to restrict both modalities so as
to get calculi which are terminating inductively and productive coinductively.
We exemplify this idea by analysing a fragment of $\ell\Lambda$ built around
the principles of $\mathsf{SLL}$ and $\mathsf{4LL}$. Interestingly, it enjoys
confluence, contrarily to what happens in ordinary infinitary
$\lambda$-calculi.


title: A neutrino interaction with two vertices topology detected by OPERA

abstract:
  The OPERA experiment has reported the detection of five $\nu_{\tau}$
candidates in the CNGS $\nu_{\mu}$ beam, allowing to reject the background-only
hypothesis at the 5.1$\sigma$ level. Besides these events, on May 23$^{rd}$
2011, OPERA detected a "neutral current like" interaction with two secondary
vertices. Such topologies mainly arise from Charged Current interactions of a
$\nu_{\tau}$ with associated charm quark production or from Neutral Current
interactions of a $\nu_{\mu}$ with production of a charm anti-charm pair. These
topologies have generally low probabilities. A dedicated multivariate analysis
is in progress to allow discriminating between these two hypotheses. Here the
event topology is described in detail and preliminary results of the
classifiers for all possible contributions are given.


title:
Hydrodynamic coupled modes of a nematic under a temperature gradient and
  a uniform gravitational field

abstract:
  Fluctuating hydrodynamics (FH) describes the dynamics of the fluctuations for
fluids at mesoscopic scales. Here we use this approach to study the
fluctuations of the hydrodynamic variables of a thermotropic nematic liquid
crystal (NLC) in a nonequilibrium steady state (NESS). This state is induced by
an externally imposed temperature gradient and a uniform gravity field. We
calculate analytically both, the equilibrium and nonequilibrium hydrodynamic
modes. We find that in this NESS the nonequilibrium effects produced by the
external gradients only affect the longitudinal variables. This gives rise to a
pair of sound modes, one orientation mode of the director and two visco-heat
modes formed by the coupling of the shear and thermal modes. We also find that
the last three modes exhibit the largest changes. The analytical expressions
that we have found for the visco-heat modes imply that the heat and shear modes
of the NLC are coupled, that they reduce to those of simple fluid in the
isotropic limit and that these modes may become propagative, a feature that
also occurs in the simple fluid. In the isotropic limit of the nematic our
results also reduce to the hydrodynamic modes of a simple fluid in the presence
of the same temperature gradient and the pressure gradient produced by the
gravity field.


title: Particle-in-cell study of the ion-to-electron sheath transition

abstract:
  The form of a sheath near a small electrode, with bias changing from below to
above the plasma potential is studied using 2D particle-in-cell (PIC)
simulations. Five cases are studied: (A) an electrode biased more than the
electron temperature ($T_e/e$) below the plasma potential, (B) an electrode
biased less than $T_e/2e$ below the plasma potential, (C) an electrode biased
nearly at the plasma potential, (D) an electrode biased more than $T_i/2e$ but
less than $T_e/2e$ above the plasma potential, and (E) an electrode biased much
greater than $T_e/2e$ above the plasma potential. In case (A), the electron
velocity distribution function (EVDF) is observed to be Maxwellian with a
Boltzmann-type exponential density decay through the ion sheath and presheath.
In cases (B) and (C), the EVDFs exhibit a loss-cone type truncation due to fast
electrons overcoming the small potential difference between the electrode and
plasma. No sheath is present in this regime, and the plasma remains
quasineutral up to the electrode. The EVDF truncation leads to a presheath-like
density and flow velocity gradient. In case (D) an electron sheath is present,
and essentially all ions are repelled. Here the truncation driven behavior
persists, but is accompanied by a shift in the maximum value of the EVDF that
is not present in the negative bias cases. In case (E), the flow shift becomes
greater and the loss-cone moves further into the tail of the EVDF. In this case
the flow moment has significant contributions from both the flow shift of the
EVDF maximum, and the loss-cone truncation.


title:
A complex Ruelle-Perron-Frobenius theorem for infinite Markov shifts
  with applications to renewal theory

abstract:
  We prove a complex Ruelle-Perron-Frobenius theorem for Markov shifts over an
infinite alphabet, whence extending results by M. Pollicott from the finite to
the infinite alphabet setting. As an application we obtain an extension of
renewal theory in symbolic dynamics, as developed by S. P. Lalley and in the
sequel generalised by the second author, now covering the infinite alphabet
case.


title:
Fast and Accurate Inference on Gravitational Waves from Precessing
  Compact Binaries

abstract:
  Inferring astrophysical information from gravitational waves emitted by
compact binaries is one of the key science goals of gravitational-wave
astronomy. In order to reach the full scientific potential of
gravitational-wave experiments we require techniques to mitigate the cost of
Bayesian inference, especially as gravitational-wave signal models and analyses
become increasingly sophisticated and detailed. Reduced order models (ROMs) of
gravitational waveforms can significantly reduce the computational cost of
inference by removing redundant computations. In this paper we construct the
first reduced order models of gravitational-wave signals that include the
effects of spin-precession, inspiral, merger, and ringdown in compact object
binaries, and which are valid for component masses describing binary neutron
star, binary black hole and mixed binary systems. This work utilizes the
waveform model known as "IMRPhenomPv2". Our ROM enables the use of a fast
reduced order quadrature (ROQ) integration rule which allows us to approximate
Bayesian probability density functions at a greatly reduced computational cost.
We find that the ROQ rule can be used to speed up inference by factors as high
as 300 without introducing systematic bias. This corresponds to a reduction in
computational time from around half a year to a half a day, for the longest
duration/lowest mass signals. The ROM and ROQ rule are available with the main
inference library of the LIGO Scientific Collaboration, LALInference.


title:
Series extension: Predicting approximate series coefficients from a
  finite number of exact coefficients

abstract:
  Given the first 20-100 coefficients of a typical generating function of the
type that arises in many problems of statistical mechanics or enumerative
combinatorics, we show that the method of differential approximants performs
surprisingly well in predicting (approximately) subsequent coefficients. These
can then be used by the ratio method to obtain improved estimates of critical
parameters. In favourable cases, given only the first 20 coefficients, the next
100 coefficients are predicted with useful accuracy. More surprisingly, this is
also the case when the method of differential approximants does not do a useful
job in estimating the critical parameters, such as those cases in which one has
stretched exponential asymptotic behaviour. Nevertheless, the coefficients are
predicted with surprising accuracy. As one consequence, significant computer
time can be saved in enumeration problems where several runs would normally be
made, modulo different primes, and the coefficients constructed from their
values modulo different primes. Another is in the checking of newly calculated
coefficients. We believe that this concept of approximate series extension
opens up a whole new chapter in the method of series analysis.


title: The Algorithmic Autoregulation Software Development Methodology

abstract:
  We present a new self-regulating methodology for coordinating distributed
team work called Algorithmic Autoregulation (AA), based on recent social
networking concepts and individual merit. Team members take on an egalitarian
role, and stay voluntarily logged into so-called AA sessions for part of their
time (e.g. 2 hours per day), during which they create periodical logs - short
text sentences - they wish to share about their activity with the team. These
logs are publicly aggregated in a website and are peer-validated after the end
of a session, as in code review. A short screencast is ideally recorded at the
end of each session to make AA logs more understandable. This methodology has
shown to be well-suited for increasing the efficiency of distributed teams
working on Global Software Development (GSD), as observed in our reported
experience in actual real-world situations. This efficiency boost is mainly
achieved through 1) built-in asynchronous on-demand communication in
conjunction with documentation of work, products, and processes, and 2) reduced
need for central management, meetings or time-consuming reports. Hence, the AA
methodology legitimizes and facilitates the activities of a distributed
software team. It thus enables other entities to have a solid means to fund
these activities, allowing for new and concrete business models to emerge for
very distributed software development. AA has been proposed, at its core, as a
way of sustaining self-replicating hacker initiatives. These claims are
discussed in a real case-study of running a distributed free software hacker
team called Lab Macambira.


title: Multiview Differential Geometry of Curves

abstract:
  The field of multiple view geometry has seen tremendous progress in
reconstruction and calibration due to methods for extracting reliable point
features and key developments in projective geometry. Point features, however,
are not available in certain applications and result in unstructured point
cloud reconstructions. General image curves provide a complementary feature
when keypoints are scarce, and result in 3D curve geometry, but face challenges
not addressed by the usual projective geometry of points and algebraic curves.
We address these challenges by laying the theoretical foundations of a
framework based on the differential geometry of general curves, including
stationary curves, occluding contours, and non-rigid curves, aiming at stereo
correspondence, camera estimation (including calibration, pose, and multiview
epipolar geometry), and 3D reconstruction given measured image curves. By
gathering previous results into a cohesive theory, novel results were made
possible, yielding three contributions. First we derive the differential
geometry of an image curve (tangent, curvature, curvature derivative) from that
of the underlying space curve (tangent, curvature, curvature derivative,
torsion). Second, we derive the differential geometry of a space curve from
that of two corresponding image curves. Third, the differential motion of an
image curve is derived from camera motion and the differential geometry and
motion of the space curve. The availability of such a theory enables novel
curve-based multiview reconstruction and camera estimation systems to augment
existing point-based approaches. This theory has been used to reconstruct a "3D
curve sketch", to determine camera pose from local curve geometry, and
tracking; other developments are underway.


title: Analytic prediction for planar turbulent boundary layers

abstract:
  Analytic predictions of mean velocity profile (MVP) and streamwise ($x$)
development of related integral quantities are presented for flows in channel
and turbulent boundary layer (TBL), based on a symmetry analysis of eddy length
and total stress. Specific predictions are the friction velocity $u_\tau$: ${
U_e/u_\tau }\approx 2.22\ln Re_x+2.86-3.83\ln(\ln Re_x)$; the boundary layer
thickness $\delta_e$: $x/\delta_e \approx 7.27\ln Re_x-5.18-12.52\ln(\ln
Re_x)$; the momentum thickness Reynolds number: $Re_x/Re_\theta=4.94[{(\ln
{{\mathop{\rm Re}\nolimits} _{\theta} } + 1.88)^2} + 1]$, all in good agreement
with empirical data.


title: A Pohozaev Identity for the Fractional H$\acute{e}$non System

abstract:
  In this paper, we study the Pohozaev identity associated with a
H$\acute{e}$non-Lane-Emden system involving the fractional Laplacian:
  \begin{equation}
  \left\{\begin{array}{ll}
  (-\triangle)^su=|x|^av^p,&x\in\Omega,
  (-\triangle)^sv=|x|^bu^q,&x\in\Omega, u=v=0,&x\in R^n\backslash\Omega,
  \end{array}
  \right.
  \end{equation} in a star-shaped and bounded domain $\Omega$ for $s\in(0,1)$.
As an application of our identity, we deduce the nonexistence of positive
solutions in the critical and supercritical cases.


title: Inclusion graph of subgroups of a group

abstract:
  For a finite group $G$, we define the inclusion graph of subgroups of $G$,
denoted by $\mathcal I(G)$, is a graph having all the proper subgroups of $G$
as its vertices and two distinct vertices $H$ and $K$ in $\mathcal I(G)$ are
adjacent if and only if either $H \subset K$ or $K \subset H$. In this paper,
we classify the finite groups whose inclusion graph of subgroups is one of
complete, bipartite, tree, star, path, cycle, disconnected, claw-free. Also we
classify the finite abelian groups whose inclusion graph of subgroups is
planar. For any given finite group, we estimate the clique number, chromatic
number, girth of its inclusion graph of subgroups and for a finite abelian
group, we estimate the diameter of its inclusion graph of subgroups. Among the
other results, we show that some groups can be determined by their inclusion
graph of subgroups


title: Theory of Thomson scattering in inhomogeneous media

abstract:
  Thomson scattering of laser light is one of the most fundamental diagnostics
of plasma density, temperature and magnetic fields. It relies on the assumption
that the properties in the probed volume are homogeneous and constant during
the probing time. On the other hand, laboratory plasmas are seldom uniform and
homogeneous on the temporal and spatial dimensions over which data is
collected. This is partic- ularly true for laser-produced high-energy-density
matter, which often exhibits steep gradients in temperature, density and
pressure, on a scale determined by the laser focus. Here, we discuss the
modification of the cross section for Thomson scattering in fully-ionized media
exhibiting steep spatial inhomogeneities and/or fast temporal fluctuations. We
show that the predicted Thomson scattering spectra are greatly altered compared
to the uniform case, and may even lead to violations of detailed balance.
Therefore, careful interpretation of the spectra is necessary for spatially or
temporally inhomogeneous systems.

categories: physics.plasm-ph astro-ph.IM cond-mat.stat-mech physics.optics


title:
Wall-Crossing implies Brill-Noether. Applications of stability
  conditions on surfaces

abstract:
  Over the last few years, wall-crossing for Bridgeland stability conditions
has led to a large number of results in algebraic geometry, particular on
birational geometry of moduli spaces.
  We illustrate some of the methods behind these result by reproving
Lazarsfeld's Brill-Noether theorem for curves on K3 surfaces via wall-crossing.
We conclude with a survey of recent applications of stability conditions on
surfaces.
  The intended reader is an algebraic geometer with a limited working knowledge
of derived categories. This article is based on the author's talk at the AMS
Summer Institute on Algebraic Geometry in Utah, July 2015.


title: On the geometry of the ricochet locus

abstract:
  This paper is a study of the so-called `ricochet configuration' (or
$R$-configuration) which arises in the context of Pascal's theorem. We give a
geometric proof of the fact that a specific pair of Pascal lines is coincident
for a sextuple in $R$-configuration. We calculate the symmetry group of a
generic $R$-configuration, as well as the degree of the subvariety ${\mathcal
R} \subseteq {\mathbb P}^6$ of all such configurations. We also determine the
$SL(2)$-equivariant defining equations for ${\mathcal R}$, and show that it is
an ideal-theoretic complete intersection of two invariant hypersurfaces.


title: Market-based vs. Price-based Microgrid Optimal Scheduling

abstract:
  An optimal scheduling model for a microgrid participating in the electricity
distribution market in interaction with a Distribution Market Operator (DMO) is
proposed in this paper. The DMO administers the established electricity market
in the distribution level, sets electricity prices, determines the amount of
the power exchange among market participants, and interacts with the
Independent System Operator (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. Numerical simulations exhibit the application and the effectiveness of
the proposed market-based microgrid scheduling model and further investigate
merits over a price-based scheme.


title: Localization in interacting fermionic chains with quasi-random disorder

abstract:
  We consider a system of fermions with a quasi-random almost-Mathieu disorder
interacting through a many-body short range potential. We establish exponential
decay of the zero temperature correlations, indicating localization of the
interacting ground state, for weak hopping and interaction and almost
everywhere in the frequency and phase; this extends the analysis in \cite{M} to
chemical potentials outside spectral gaps. The proof is based on
Renormalization Group and is inspired by techniques developed to deal with KAM
Lindstedt series.


title:
Critical exponent for nonlinear wave equations with frictional and
  viscoelastic damping terms

abstract:
  In this paper, we study the Cauchy problem for a nonlinear wave equation with
frictional and viscoelastic damping terms. Our aim is to obtain the threshold,
to classify the global existence of solution for small data or the finite time
blow-up pf the solution, with respect to the growth order of the nonlinearity.


title: Contact Hamiltonian Mechanics

abstract:
  In this work we introduce contact Hamiltonian mechanics, an extension of
symplectic Hamiltonian mechanics, and show that it is a natural candidate for a
geometric description of non-dissipative and dissipative systems. For this
purpose we review in detail the major features of standard symplectic
Hamiltonian dynamics and show that all of them can be generalized to the
contact case.

categories: math-ph math.MP math.SG physics.class-ph


title: Rank gradients of infinite cyclic covers of Kaehler manifolds

abstract:
  Given a Kaehler group $G$ and a primitive class $\phi \in H^1(G;Z)$, we show
that the rank gradient of $(G;\phi)$ is zero if and only if Ker $\phi$ is
finitely generated. Using this approach, we give a quick proof of the fact
(originally due to Napier and Ramachandran) that Kaehler groups are not
properly ascending or descending HNN extensions. Further investigation of the
properties of Bieri-Neumann-Strebel invariants of Kaehler groups allows us to
show that a large class of groups of orientation-preserving PL homeomorphisms
of an interval, which generalize Thompson's group $F$, are not Kaehler.


title: Quantum Cognition Beyond Hilbert Space I: Fundamentals

abstract:
  The formalism of quantum theory in Hilbert space has been applied with
success to the modeling and explanation of several cognitive phenomena, whereas
traditional cognitive approaches were problematical. However, this 'quantum
cognition paradigm' was recently challenged by its proven impossibility to
simultaneously model 'question order effects' and 'response replicability'. In
Part I of this paper we describe sequential dichotomic measurements within an
operational and realistic framework for human cognition elaborated by
ourselves, and represent them in a quantum-like 'extended Bloch representation'
where the Born rule of quantum probability does not necessarily hold. In Part
II we apply this mathematical framework to successfully model question order
effects, response replicability and unpacking effects, thus opening the way
toward quantum cognition beyond Hilbert space.


title: Efficient Optimization for Rank-based Loss Functions

abstract:
  The accuracy of information retrieval systems is often measured using complex
loss functions such as the average precision (AP) or the normalized discounted
cumulative gain (NDCG). Given a set of positive and negative samples, the
parameters of a retrieval system can be estimated by minimizing these loss
functions. However, the non-differentiability and non-decomposability of these
loss functions does not allow for simple gradient based optimization
algorithms. This issue is generally circumvented by either optimizing a
structured hinge-loss upper bound to the loss function or by using asymptotic
methods like the direct-loss minimization framework. Yet, the high
computational complexity of loss-augmented inference, which is necessary for
both the frameworks, prohibits its use in large training data sets. To
alleviate this deficiency, we present a novel quicksort flavored algorithm for
a large class of non-decomposable loss functions. We provide a complete
characterization of the loss functions that are amenable to our algorithm, and
show that it includes both AP and NDCG based loss functions. Furthermore, we
prove that no comparison based algorithm can improve upon the computational
complexity of our approach asymptotically. We demonstrate the effectiveness of
our approach in the context of optimizing the structured hinge loss upper bound
of AP and NDCG loss for learning models for a variety of vision tasks. We show
that our approach provides significantly better results than simpler
decomposable loss functions, while requiring a comparable training time.


title: Quantum cognition beyond Hilbert space II: Applications

abstract:
  The research on human cognition has recently benefited from the use of the
mathematical formalism of quantum theory in Hilbert space. However, cognitive
situations exist which indicate that the Hilbert space structure, and the
associated Born rule, would be insufficient to provide a satisfactory modeling
of the collected data, so that one needs to go beyond Hilbert space. In Part I
of this paper we follow this direction and present a general tension-reduction
(GTR) model, in the ambit of an operational and realistic framework for human
cognition. In this Part II we apply this non-Hilbertian quantum-like model to
faithfully reproduce the probabilities of the 'Clinton/Gore' and 'Rose/Jackson'
experiments on question order effects. We also explain why the GTR-model is
needed if one wants to deal, in a fully consistent way, with response
replicability and unpacking effects.


title: Faithful tropicalization of hypertoric varieties

abstract:
  The hypertoric variety $\mathfrak{M}_{\mathcal{A}}$ defined by an affine
arrangement $\mathcal{A}$ admits a natural tropicalization, induced by its
embedding in a Lawrence toric variety. We explicitly describe the polyhedral
structure of this tropicalization. Using a recent result of Gubler, Rabinoff,
and Werner, we prove that there is a continuous section of the tropicalization
map.


title: Topological entropy of a Lie group automorphism

abstract:
  Let {\phi} be an automorphism on a connected Lie group G. Through several
G-subgroups associated to the dynamics of {\phi} we analyze their topological
entropy. Assume that G belongs to the class of finite semisimple center Lie
groups which admits a {\phi} invariant Levi subgroup. Then we prove that the
topological entropy information of {\phi} is contained in the toral component
of the unstable subgroup of {\phi} in the radical of G. We specialize the main
result in a couple of interesting situations.


title: Symmetric products of equivariantly formal spaces

abstract:
  Let X be a CW complex with a continuous action of a topological group G. We
show that if X is equivariantly formal for singular cohomology with
coefficients in a field, then so are all symmetric products of X and in fact
all its Gamma-products. In particular, symmetric products of quasi-projective
M-varieties are again M-varieties. This generalizes a result by Biswas and
D'Mello about symmetric products of M-curves. We also discuss several related
questions.


title: A General Constrained Shortest Path Approach for Virtual Path Embedding

abstract:
  Network virtualization has become a fundamental technology to deliver
services for emerging data-intensive applications in fields such as
bioinformatics and retail analytics hosted at multi-data center scales. To
create and maintain a successful virtual network service, the problem of
generating a constrained path manifests both in the management plane with a
physical path creation (chains of virtual network functions or virtual link
embedding) and in the data plane with on-demand path adaptation (traffic
steering with Service Level Objective (SLO) guarantees). In this paper, we
define the virtual path embedding problem to subsume the virtual link embedding
and the constrained traffic steering problems, and propose a new scheme to
solve it optimally. Specifically, we introduce a novel algorithm viz.,
"Neighborhood Method" (NM) which provides an on-demand path with SLO guarantees
while reducing expensive over provisioning. We show that by solving the Virtual
Path Embedding problem in a set of diverse topology scenarios we gain up to 20%
in network utilization, and up to 150% in energy efficiency, compared to the
existing path embedding solutions.