title:
Confinement transition to density wave order in metallic doped spin
  liquids

abstract:
  Insulating quantum spin liquids can undergo a confinement transition to a
valence bond solid state via the condensation of topological excitations of the
associated gauge theory. We extend the theory of such transitions to
fractionalized Fermi liquids (FL*): these are metallic doped spin liquids in
which the Fermi surfaces only have gauge neutral quasiparticles. Using insights
from a duality transform on a doped quantum dimer model for the U(1)-FL* state,
we show that projective symmetry group of the theory of the topological
excitations remains unmodified, but the Fermi surfaces can lead to additional
frustrating interactions. We propose a theory for the confinement transition of
$\mathbb{Z}_2$-FL* states via the condensation of visons. A variety of
confining, incommensurate density wave states are possible, including some that
are similar to the incommensurate $d$-form factor density wave order observed
in several recent experiments on the cuprate superconductors.


title: Generation of mechanical interference fringes by multi-photon counting

abstract:
  Exploring the quantum behaviour of macroscopic objects provides an intriguing
avenue to study the foundations of physics and to develop a suite of
quantum-enhanced technologies. One prominent path of study is provided by
quantum optomechanics which utilizes the tools of quantum optics to control the
motion of macroscopic mechanical resonators. Despite excellent recent progress,
the preparation of mechanical quantum superposition states remains outstanding
due to weak coupling and thermal decoherence. Here we present a novel
optomechanical scheme that significantly relaxes these requirements allowing
the preparation of quantum superposition states of motion of a mechanical
resonator by exploiting the nonlinearity of multi-photon quantum measurements.
Our method is capable of generating non-classical mechanical states without the
need for strong single photon coupling, is resilient against optical loss, and
offers more favourable scaling against initial mechanical thermal occupation
than existing schemes. Moreover, our approach allows the generation of larger
superposition states by projecting the optical field onto NOON states. We
experimentally demonstrate this multi-photon-counting technique on a mechanical
thermal state in the classical limit and observe interference fringes in the
mechanical position distribution that show phase superresolution. This opens a
feasible route to explore and exploit quantum phenomena at a macroscopic scale.


title: A Simple Approach to the Supernova Progenitor-Explosion Connection

abstract:
  We present a new approach to understand the landscape of supernova explosion
energies, ejected nickel masses, and neutron star birth masses. In contrast to
other recent parametric approaches, our model predicts the properties of
neutrino-driven explosions based on the pre-collapse stellar structure without
the need for hydrodynamic simulations. The model is based on physically
motivated scaling laws and simple differential equations describing the shock
propagation, the contraction of the neutron star, the neutrino emission, the
heating conditions, and the explosion energetics. Using model parameters
compatible with multi-D simulations and a fine grid of thousands of supernova
progenitors, we obtain a variegated landscape of neutron star and black hole
formation similar to other parameterised approaches and find good agreement
with semi-empirical measures for the "explodability" of massive stars. Our
predicted explosion properties largely conform to observed correlations between
the nickel mass and explosion energy. Accounting for the coexistence of
outflows and downflows during the explosion phase, we naturally obtain a
positive correlation between explosion energy and ejecta mass. These
correlations are relatively robust against parameter variations, but our
results suggest that there is considerable leeway in parametric models to widen
or narrow the mass ranges for black hole and neutron star formation and to
scale explosion energies up or down. Our model is currently limited to an
all-or-nothing treatment of fallback and there remain some minor discrepancies
between model predictions and observational constraints.


title:
Reconciling dwarf galaxies with LCDM cosmology: Simulating a realistic
  population of satellites around a Milky Way-mass galaxy

abstract:
  Low-mass "dwarf" galaxies represent the most significant challenges to the
cold dark matter (CDM) model of cosmological structure formation. Because these
faint galaxies are (best) observed within the Local Group (LG) of the Milky Way
(MW) and Andromeda (M31), understanding their formation in such an environment
is critical. We present first results from the Latte Project: the Milky Way on
FIRE (Feedback in Realistic Environments). This simulation models the formation
of a MW-mass galaxy to z = 0 within LCDM cosmology, including dark matter, gas,
and stars at unprecedented resolution: baryon particle mass of 7070 Msun with
gas kernel/softening that adapts down to 1 pc (with a median of 25 - 60 pc at z
= 0). Latte was simulated using the GIZMO code with a mesh-free method for
accurate hydrodynamics and the FIRE-2 model for star formation and explicit
feedback within a multi-phase interstellar medium. For the first time, Latte
self-consistently resolves the spatial scales corresponding to half-light radii
of dwarf galaxies that form around a MW-mass host down to Mstar > 10^5 Msun.
Latte's population of dwarf galaxies agrees with the LG across a broad range of
properties: (1) distributions of stellar masses and stellar velocity
dispersions (dynamical masses), including their joint relation; (2) the
mass-metallicity relation; and (3) a diverse range of star-formation histories,
including their mass dependence. Thus, Latte produces a realistic population of
dwarf galaxies at Mstar > 10^5 Msun that does not suffer from the "missing
satellites" or "too big to fail" problems of small-scale structure formation.
We conclude that baryonic physics can reconcile observed dwarf galaxies with
standard LCDM cosmology.


title: Thermal quantum metrology in memoryless and correlated environments

abstract:
  In bosonic quantum metrology, the estimate of a loss parameter is typically
performed by means of pure states, such as coherent, squeezed or entangled
states, while mixed thermal probes are discarded for their inferior
performance. Here we show that thermal sources with suitable correlations can
be engineered in such a way to approach, or even surpass, the error scaling of
coherent states in the presence of general Gaussian decoherence. Our findings
pave the way for practical quantum metrology with thermal sources in optical
instruments (e.g., photometers) or at different wavelengths (e.g., far
infrared, microwave or X-ray) where the generation of quantum features, such as
coherence, squeezing or entanglement, may be extremely challenging.


title: Loop corrections to the antibrane potential

abstract:
  Antibranes provide some of the most generic ways to uplift Anti-de Sitter
flux compactifications to de Sitter, and there is a growing body of evidence
that antibranes placed in long warped throats such as the Klebanov-Strassler
warped deformed conifold solution have a brane-brane-repelling tachyon. This
tachyon was first found in the regime of parameters in which the backreaction
of the antibranes is large, and its existence was inferred from a highly
nontrivial cancellation of certain terms in the inter-brane potential. We use a
brane effective action approach, similar to that proposed by Michel, Mintun,
Polchinski, Puhm and Saad in arXiv:1412.5702, to analyze antibranes in
Klebanov-Strassler when their backreaction is small, and find a regime of
parameters where all perturbative contributions to the action can be computed
explicitly. We find that the cancellation found at strong coupling is also
present in the weak-coupling regime, and we establish its existence to all
loops. Our calculation indicates that the spectrum of the antibrane worldvolume
theory is not gapped, and may generically have a tachyon. Hence uplifting
mechanisms involving antibranes remain questionable even when backreaction is
small.


title:
Hierarchical Bayesian inference of galaxy redshift distributions from
  photometric surveys

abstract:
  Accurately characterizing the redshift distributions of galaxies is essential
for analysing deep photometric surveys and testing cosmological models. We
present a technique to simultaneously infer redshift distributions and
individual redshifts from photometric galaxy catalogues. Our model constructs a
piecewise constant representation (effectively a histogram) of the distribution
of galaxy types and redshifts, the parameters of which are efficiently inferred
from noisy photometric flux measurements. This approach can be seen as a
generalization of template-fitting photometric redshift methods and relies on a
library of spectral templates to relate the photometric fluxes of individual
galaxies to their redshifts. We illustrate this technique on simulated galaxy
survey data, and demonstrate that it delivers correct posterior distributions
on the underlying type and redshift distributions, as well as on the individual
types and redshifts of galaxies. We show that even with uninformative priors,
large photometric errors and parameter degeneracies, the redshift and type
distributions can be recovered robustly thanks to the hierarchical nature of
the model, which is not possible with common photometric redshift estimation
techniques. As a result, redshift uncertainties can be fully propagated in
cosmological analyses for the first time, fulfilling an essential requirement
for the current and future generations of surveys.


title:
Another Path for the Emergence of Modified Galactic Dynamics from Dark
  Matter Superfluidity

abstract:
  In recent work we proposed a novel theory of dark matter (DM) superfluidity
that matches the successes of the LambdaCDM model on cosmological scales while
simultaneously reproducing MOdified Newtonian Dynamics (MOND) phenomenology on
galactic scales. The agents responsible for mediating the MONDian force law are
superfluid phonons that couple to ordinary (baryonic) matter. In this paper we
propose an alternative way for the MOND phenomenon to emerge from DM
superfluidity. The central idea is to use higher-gradient corrections in the
superfluid effective theory. These next-to-leading order terms involve
gradients of the gravitational potential, and therefore effectively modify the
gravitational force law. In the process we discover a novel mechanism for
generating the non-relativistic MOND action, starting from a theory that is
fully analytic in all field variables. The idea, inspired by the symmetron
mechanism, uses the spontaneous breaking of a discrete symmetry. For large
acceleration, the symmetry is unbroken and the action reduces to Einstein
gravity. For small acceleration, the symmetry is spontaneously broken and the
action reduces to MONDian gravity. Cosmologically, however, the universe is
always in the Einstein-gravity, symmetry-restoring phase. The expansion history
and linear growth of density perturbations are therefore indistinguishable from
LambdaCDM cosmology.


title:
ALMA observations of cold molecular gas filaments trailing rising radio
  bubbles in PKS0745-191

abstract:
  We present ALMA observations of the CO(1-0) and CO(3-2) line emission tracing
filaments of cold molecular gas in the central galaxy of the cluster
PKS0745-191. The total molecular gas mass of 4.6 +/- 0.3 x 10^9 solar masses,
assuming a Galactic X_{CO} factor, is divided roughly equally between three
filaments each extending radially 3-5 kpc from the galaxy centre. The emission
peak is located in the SE filament roughly 1 arcsec (2 kpc) from the nucleus.
The velocities of the molecular clouds in the filaments are low, lying within
+/-100 km/s of the galaxy's systemic velocity. Their FWHMs are less than 150
km/s, which is significantly below the stellar velocity dispersion. Although
the molecular mass of each filament is comparable to a rich spiral galaxy, such
low velocities show that the filaments are transient and the clouds would
disperse on <10^7 yr timescales unless supported, likely by the indirect effect
of magnetic fields. The velocity structure is inconsistent with a merger origin
or gravitational free-fall of cooling gas in this massive central galaxy. If
the molecular clouds originated in gas cooling even a few kpc from their
current locations their velocities would exceed those observed. Instead, the
projection of the N and SE filaments underneath X-ray cavities suggests they
formed in the updraft behind bubbles buoyantly rising through the cluster
atmosphere. Direct uplift of the dense gas by the radio bubbles appears to
require an implausibly high coupling efficiency. The filaments are coincident
with low temperature X-ray gas, bright optical line emission and dust lanes
indicating that the molecular gas could have formed from lifted warmer gas that
cooled in situ.


title: Cosmologists in Search of Planet Nine: the Case for CMB Experiments

abstract:
  Cosmology experiments at mm-wavelengths can detect Planet Nine if it is the
size of Neptune, has an effective temperature of 40 K, and is 700 AU from the
Sun. It would appear as a ~30 mJy source at 1 mm with an annual parallax of ~5
arcmin. The challenge is to distinguish it from the approximately 4000
foreground asteroids brighter than 30 mJy. Fortunately, these asteroids are
known to the Minor Planet Center and can be identified because they move across
a resolution element in a matter of hours, orders of magnitude faster than
Planet Nine. If Planet Nine is smaller, colder, and/or more distant than
expected, then it could be as faint as 1 mJy at 1 mm. There are roughly $10^6$
asteroids this bright and many are unknown, making current cosmology
experiments confusion limited for moving sources. Nonetheless, it may still be
possible to find the proverbial needle in the haystack using a matched filter.
This would require mm telescopes with high angular resolution and high
sensitivity in order to alleviate confusion and to enable the identification of
moving sources with relatively short time baselines. Regardless of its mm flux
density, searching for Planet Nine would require frequent radio measurements
for large swaths of the sky, including the ecliptic and Galactic plane. Even if
Planet Nine had already been detected by other means, measuring its mm-flux
would constrain its internal energy budget, and therefore help resolve the
mystery of Uranus and Neptune, which have vastly different internal heat.


title:
Light induced enhancement of superconductivity via melting of competing
  bond-density wave order in underdoped cuprates

abstract:
  We develop a theory for light-induced superconductivity in underdoped
cuprates in which the competing bond-density wave order is suppressed by
driving phonons with light. Close to a bond-density wave instability in a
system with a small Fermi surface, such as a fractionalized Fermi liquid, we
show that the coupling of electrons to phonons is strongly enhanced at the
bond-density wave ordering wavevectors, leading to a strong softening of
phonons at these wavevectors. For a model of classical phonons with anharmonic
couplings, we show that the combination of strong softening and driving can
lead to large phonon oscillations. When coupled to a phenomenological model
describing the competition between bond-density wave order and
superconductivity, these phonon oscillations melt bond-density wave order,
thereby enhancing pairing correlations.


title:
Modeling Fermi Large Area Telescope and Multiwavelength Data from
  Blazars

abstract:
  Blazars are active galactic nuclei with relativistic jets pointed at the
Earth, making them extremely bright at essentially all wavelengths, from radio
to gamma rays. I review the modeling of this broadband spectral energy
distributions of these objects, and what we have learned, with a focus on gamma
rays.


title: Gamma-ray Limits on Neutrino Lines

abstract:
  MMonochromatic neutrinos from dark matter annihilations ($\chi\chi\to
\nu\bar\nu$) are always produced in association with a gamma-ray spectrum
generated by electroweak bremsstrahlung. Consequently, these neutrino lines can
be searched for not only with neutrino detectors but also indirectly with
gamma-ray telescopes. Here, we derive limits on the dark matter annihilation
cross section into neutrinos based on recent Fermi-LAT and HESS data. We find
that, for dark matter masses above 200 GeV, gamma-ray data actually set the
most stringent constraints on neutrino lines from dark matter annihilation and,
therefore, an upper bound on the dark matter total annihilation cross section.
In addition, we point out that gamma-ray telescopes, unlike neutrino detectors,
have the potential to distinguish the flavor of the final state neutrino. Our
results indicate that we have already entered into a new era where gamma-ray
telescopes are more sensitive than neutrino detectors to neutrino lines from
dark matter annihilation.


title:
Evidence for non-stellar rest-frame near-IR emission associated with
  increased star formation in galaxies at $z \sim 1$

abstract:
  We explore the presence of non-stellar rest-frame near-IR ($2-5 \ \mu
\mathrm{m}$) emission in galaxies at $z \sim 1$. Previous studies identified
this excess in relatively small samples and suggested that such non-stellar
emission, which could be linked to the $3.3 \ \mu \mathrm{m}$ polycyclic
aromatic hydrocarbons feature or hot dust emission, is associated with an
increased star formation rate (SFR). In this Letter, we confirm and quantify
the presence of an IR excess in a significant fraction of galaxies in the
3D-HST GOODS catalogs. By constructing a matched sample of galaxies with and
without strong non-stellar near-IR emission, we find that galaxies with such
emission are predominantly star-forming galaxies. Moreover, star-forming
galaxies with an excess show increased mid- and far-IR and H$\alpha$ emission
compared to other star-forming galaxies without. While galaxies with a near-IR
excess show a larger fraction of individually detected X-ray active galactic
nuclei (AGNs), an X-ray stacking analysis, together with the IR-colors and
H$\alpha$ profiles, shows that AGNs are unlikely to be the dominant source of
the excess in the majority of galaxies. Our results suggest that non-stellar
near-IR emission is linked to increased SFRs and is ubiquitous among
star-forming galaxies. As such, the near-IR emission might be a powerful tool
to measure SFRs in the era of the James Webb Space Telescope.


title:
Particle Acceleration and the Origin of X-ray Flares in GRMHD
  simulations of Sgr A*

abstract:
  Significant X-ray variability and flaring has been observed from Sgr A* but
is poorly understood from a theoretical standpoint. We perform GRMHD
simulations that take into account a population of non-thermal electrons with
energy distributions and injection rates that are motivated by PIC simulations
of magnetic reconnection. We explore the effects of including these non-thermal
electrons on the predicted broadband variability of Sgr A* and find that X-ray
variability is a generic result of localizing non-thermal electrons to highly
magnetized regions, where particles are likely to be accelerated via magnetic
reconnection. The proximity of these high-field regions to the event horizon
forms a natural connection between IR and X-ray variability and accounts for
the rapid timescales associated with the X-ray flares. The qualitative nature
of this variability is consistent with observations, producing X-ray flares
that are always coincident with IR flares, but not vice versa, i.e., there are
a number of IR flares without X-ray counterparts.


title: SU(2)$_1$ chiral edge modes of a critical spin liquid

abstract:
  Protected chiral edge modes are a well-known signature of topologically
ordered phases like the Fractional Quantum Hall States. Recently, using the
framework of projected entangled pair states (PEPS) on the square lattice, we
constructed a family of chiral Resonating Valence Bond states with
$\mathbb{Z}_2$ gauge symmetry. Here we revisit and analyze in full details the
properties of the edge modes as given by their Entanglement Spectra on a
cylinder. Surprisingly, we show that the latter can be well described by a
chiral SU(2)$_1$ Conformal Field Theory (CFT), as for the $\nu=1/2$ (bosonic)
gapped Laughlin state, although our numerical data suggest a critical bulk
compatible with an emergent $U(1)$ gauge symmetry. We propose that our family
of PEPS may physically describe a boundary between a chiral topological phase
and a trivial phase.


title: A Partially Non-Ergodic Ground-Motion Prediction Equation for Europe

abstract:
  A partially non-ergodic ground-motion prediction equation is estimated for
Europe and the Middle East. Therefore, a hierarchical model is presented that
accounts for regional differences. For this purpose, the scaling of
ground-motion intensity measures is assumed to be similar, but not identical in
different regions. This is achieved by assuming a hierarchical model, where
some coefficients are treated as random variables which are sampled from an
underlying global distribution. The coefficients are estimated by Bayesian
inference. This allows one to estimate the epistemic uncertainty in the
coefficients, and consequently in model predictions, in a rigorous way. The
model is estimated based on peak ground acceleration data from nine different
European/Middle Eastern regions. There are large differences in the amount of
earthquakes and records in the different regions. However, due to the
hierarchical nature of the model, regions with only few data points borrow
strength from other regions with more data. This makes it possible to estimate
a separate set of coefficients for all regions. Different regionalized models
are compared, for which different coefficients are assumed to be regionally
dependent. Results show that regionalizing the coefficients for magnitude and
distance scaling leads to better performance of the models. The models for all
regions are physically sound, even if only very few earthquakes comprise one
region.


title: Correlation Functions of Coulomb Branch Operators

abstract:
  We consider the correlation functions of Coulomb branch operators in
four-dimensional N=2 Superconformal Field Theories (SCFTs) involving exactly
one anti-chiral operator. These extremal correlators are the "minimal"
non-holomorphic local observables in the theory. We show that they can be
expressed in terms of certain determinants of derivatives of the four-sphere
partition function of an appropriate deformation of the SCFT. This relation
between the extremal correlators and the deformed four-sphere partition
function is non-trivial due to the presence of conformal anomalies, which lead
to operator mixing on the sphere. Evaluating the deformed four-sphere partition
function using supersymmetric localization, we compute the extremal correlators
explicitly in many interesting examples. Additionally, the representation of
the extremal correlators mentioned above leads to a system of integrable
differential equations. We compare our exact results with previous perturbative
computations and with the four-dimensional tt^* equations. We also use our
results to study some of the asymptotic properties of the perturbative series
expansions we obtain in N=2 SQCD.


abstract:
  We estimate Ramsey numbers for bipartite graphs with small bandwidth and
bounded maximum degree. In particular we determine asymptotically the two and
three color Ramsey numbers for grid graphs. More generally, we determine
asymptotically the two color Ramsey number for bipartite graphs with small
bandwidth and bounded maximum degree and the three color Ramsey number for such
graphs with the additional assumption that the bipartite graph is balanced.


title: Breaking Symmetric Cryptosystems using Quantum Period Finding

abstract:
  Due to Shor's algorithm, quantum computers are a severe threat for public key
cryptography. This motivated the cryptographic community to search for
quantum-safe solutions. On the other hand, the impact of quantum computing on
secret key cryptography is much less understood. In this paper, we consider
attacks where an adversary can query an oracle implementing a cryptographic
primitive in a quantum superposition of different states. This model gives a
lot of power to the adversary, but recent results show that it is nonetheless
possible to build secure cryptosystems in it.
  We study applications of a quantum procedure called Simon's algorithm (the
simplest quantum period finding algorithm) in order to attack symmetric
cryptosystems in this model. Following previous works in this direction, we
show that several classical attacks based on finding collisions can be
dramatically sped up using Simon's algorithm: finding a collision requires
$\Omega(2^{n/2})$ queries in the classical setting, but when collisions happen
with some hidden periodicity, they can be found with only $O(n)$ queries in the
quantum model.
  We obtain attacks with very strong implications. First, we show that the most
widely used modes of operation for authentication and authenticated encryption
e.g. CBC-MAC, PMAC, GMAC, GCM, and OCB) are completely broken in this security
model. Our attacks are also applicable to many CAESAR candidates: CLOC, AEZ,
COPA, OTR, POET, OMD, and Minalpher. This is quite surprising compared to the
situation with encryption modes: Anand et al. show that standard modes are
secure with a quantum-secure PRF.
  Second, we show that Simon's algorithm can also be applied to slide attacks,
leading to an exponential speed-up of a classical symmetric cryptanalysis
technique in the quantum model.


title: Almost all primes have a multiple of small Hamming weight

abstract:
  Recent results of Bourgain and Shparlinski imply that for almost all primes
$p$ there is a multiple $mp$ that can be written in binary as $mp= 1+2^{m_1}+
\cdots +2^{m_k}, \quad 1\leq m_1 < \cdots < m_k,$ with $k=66$ or $k=16$,
respectively. We show that $k=6$ (corresponding to Hamming weight $7$)
suffices.
  We also prove there are infinitely many primes $p$ with a multiplicative
subgroup $A=<g>\subset \mathbb{F}_p^*$, for some
  $g \in \{2,3,5\}$, of size $|A|\gg p/(\log p)^3$, where the sum-product set
$A\cdot A+ A\cdot A$ does not cover $\mathbb{F}_p$ completely.


title: The AV1 Constrained Directional Enhancement Filter (CDEF)

abstract:
  This paper presents the constrained directional enhancement filter designed
for the AV1 royalty-free video codec. The in-loop filter is based on a
non-linear low-pass filter and is designed for vectorization efficiency. It
takes into account the direction of edges and patterns being filtered. The
filter works by identifying the direction of each block and then adaptively
filtering with a high degree of control over the filter strength along the
direction and across it. The proposed enhancement filter is shown to improve
the quality of the Alliance for Open Media (AOM) AV1 and Thor video codecs in
particular in low complexity configurations.


title: Discontinuous Thinning in Active Microrheology of Soft Complex Matter

abstract:
  Employing theory and numerical simulations, we demonstrate discontinuous
force thinning due to the motion of an external probe in a host medium, which
we approximate as structureless. When the driving of the probe exceeds a
critical force, the microviscosity of the medium drops abruptly by about an
order of magnitude. This phenomenon occurs for strong attractive interactions
between probe and a sufficiently dense host medium.


title: Local density of states for nanoplasmonics

abstract:
  We obtain the local density of states (LDOS) for any nanoplasmonic system in
the frequency range dominated by a localized surface plasmon. By including the
Ohmic losses in a consistent way, we show that the plasmon LDOS is proportional
to the local field intensity normalized by the absorbed power. We obtain
explicit formulas for the energy transfer (ET) between quantum emitters and
plasmons as well as between donors and acceptors situated near a plasmonic
structure. In the latter case, we find that the plasmon-assisted ET rate is
proportional to the LDOS product at the donor and acceptor positions, obtain,
in a general form, the plasmon ET enhancement factor, and establish the
transition onset between Forster-dominated and plasmon-dominated ET regimes.


title: Endpoint bounds for a class of spectral multipliers on compact manifolds

abstract:
  It is well known that the Stein-Tomas $L^2$ Fourier restriction theorem can
be used to derive sharp $L^p$ bounds for radial Fourier multipliers such as the
Bochner-Riesz means. In a similar manner, $L^p \to L^2$ estimates for spectral
projection operators have been utilized in order to obtain sharp $L^p$ bounds
for spectral multipliers of self-adjoint elliptic pseudo-differential operators
on compact manifolds. In this paper, we refine an endpoint result for spectral
multipliers due to Seeger, providing endpoint bounds in terms of Besov spaces.
Our proof is based on the ideas from the recent work by Heo, Nazarov and
Seeger, and Lee, Rogers and Seeger on radial Fourier multipliers.


title: K\"ahler Representation Theory

abstract:
  We show that Jordan-Lie-Banach algebras, which provide an abstract
characterization of quantum theory equivalent to C^* algebras, can always be
canonically represented in terms of smooth functions on a K\"ahler manifold.

categories: math-ph math.MP math.RT physics.hist-ph quant-ph


title: Revise Saturated Activation Functions

abstract:
  In this paper, we revise two commonly used saturated functions, the logistic
sigmoid and the hyperbolic tangent (tanh).
  We point out that, besides the well-known non-zero centered property, slope
of the activation function near the origin is another possible reason making
training deep networks with the logistic function difficult to train. We
demonstrate that, with proper rescaling, the logistic sigmoid achieves
comparable results with tanh.
  Then following the same argument, we improve tahn by penalizing in the
negative part. We show that "penalized tanh" is comparable and even outperforms
the state-of-the-art non-saturated functions including ReLU and leaky ReLU on
deep convolution neural networks.
  Our results contradict to the conclusion of previous works that the
saturation property causes the slow convergence. It suggests further
investigation is necessary to better understand activation functions in deep
architectures.


title:
HIV, Cardiovascular Diseases, and Chronic Arsenic Exposure co-exist in a
  Positive Synergy

abstract:
  Recent epidemiological evidences indicate that arsenic exposure increases
risk of atherosclerosis, cardiovascular diseases and microangiopathies in
addition to the serious global health concern related to its carcinogenic
effects. In experiments on animals, acute and chronic exposure to arsenic
directly correlates cardiac tachyarrhythmia, and atherogenesis in a
concentration and duration dependent manner. Moreover, the other effects of
long-term arsenic exposure include induction of non-insulin dependent diabetes
by mechanisms yet to be understood. On the other hand, there are controversial
issues, gaps in knowledge, and future research priorities of accelerated
incidences of CVD and mortalities in patients with HIV who are under long-term
anti-retroviral therapy (ART). Although, both HIV infection itself and various
components of ART initiate significant pathological alterations in the
myocardium and the vasculature, simultaneous environmental exposure to arsenic
which is more convincingly being recognized as a facilitator of HIV viral
cycling in the infected immune cells, may contribute an additional layer of
adversity in these patients. In this mini-review which have been fortified with
our own preliminary data, we will discuss some of the key current understating
of chronic arsenic exposure, and its possible impact on the accelerated HIV/ART
induced CVD. The review will conclude with notes on recent developments in
mathematical modeling in this field that probabilistically forecast incidence
prevalence as functions of aging and life style parameters, most of which vary
with time themselves; this interdisciplinary approach provides a complementary
kernel to conventional biology.


title: A new proof of a theorem of Dutertre and Fukui on Morin singularities

abstract:
  In [2], N.Dutertre and T. Fukui used Viro's integral calculus to study the
topology of stable maps $f:M\rightarrow N$ between two smooth manifolds $M$ and
$N$. They also discussed several applications to Morin maps. In particular, in
Theorem 6.2 [2], they show an equality relating the Euler characteristic of a
compact manifold $M$ and the Euler characteristic of the singular sets of a
Morin map defined on $M$.
  In this paper we show how Morse theory for manifolds with boundary can be
applied to the study of the singular sets of a Morin map in order to obtain a
new proof of Dutertre-Fukui's Theorem when $N=\mathbb{R}^n$.


title:
Emergence of a 2d macro-spin liquid in a highly frustrated 3d quantum
  magnet

abstract:
  The classical Ising model on the frustrated 3d swedenborgite lattice has
disordered spin liquid ground states for all ratios of inter- and intra-planar
couplings. Quantum fluctuations due to a transverse field give rise to several
exotic quantum phenomena. In the limit of weakly coupled Kagom\'e layers we
find a 3d version of disorder by disorder. For large out-of-plane couplings 1d
macro-spins are formed which realize a disordered macro-spin liquid on an
emerging triangular lattice. Signatures of this dimensional reduction are also
found in critical exponents of the quantum phase transition out of the fully
polarized phase into the macro-spin liquid displaying quantum criticality
typical for 2d quantum systems.


title:
Multiplicity of solutions for polyharmonic Dirichlet problems with
  exponential nonlinearities and broken symmetry

abstract:
  We prove the existence of infinitely many solutions to a class of
non-symmetric Dirichlet problems with exponential nonlinearities. Here the
domain $\Omega \subset\subset \mathbb{R}^{2l}$ where $2l$ is the order of the
equation. Considered are the problem with no symmetry requirements on the
domain, the radial problem on an annulus, and the radial problem on a ball with
a Hardy potential term.


title: The Birth of $E_8$ out of the Spinors of the Icosahedron

abstract:
  $E_8$ is prominent in mathematics and theoretical physics, and is generally
viewed as an exceptional symmetry in an eight-dimensional space very different
from the space we inhabit; for instance the Lie group $E_8$ features heavily in
ten-dimensional superstring theory. Contrary to that point of view, here we
show that the $E_8$ root system can in fact be constructed from the icosahedron
alone and can thus be viewed purely in terms of three-dimensional geometry. The
$240$ roots of $E_8$ arise in the 8D Clifford algebra of 3D space as a double
cover of the $120$ elements of the icosahedral group, generated by the root
system $H_3$. As a by-product, by restricting to even products of root vectors
(spinors) in the 4D even subalgebra of the Clifford algebra, one can show that
each 3D root system induces a root system in 4D, which turn out to also be
exactly the exceptional 4D root systems. The spinorial point of view explains
their existence as well as their unusual automorphism groups. This spinorial
approach thus in fact allows one to construct all exceptional root systems
within the geometry of three dimensions, which opens up a novel interpretation
of these phenomena in terms of spinorial geometry.


title: A Poisson process model for Monte Carlo

abstract:
  Simulating samples from arbitrary probability distributions is a major
research program of statistical computing. Recent work has shown promise in an
old idea, that sampling from a discrete distribution can be accomplished by
perturbing and maximizing its mass function. Yet, it has not been clearly
explained how this research project relates to more traditional ideas in the
Monte Carlo literature. This chapter addresses that need by identifying a
Poisson process model that unifies the perturbation and accept-reject views of
Monte Carlo simulation. Many existing methods can be analyzed in this
framework. The chapter reviews Poisson processes and defines a Poisson process
model for Monte Carlo methods. This model is used to generalize the
perturbation trick to infinite spaces by constructing Gumbel processes, random
functions whose maxima are located at samples over infinite spaces. The model
is also used to analyze A* sampling and OS*, two methods from distinct Monte
Carlo families.


title: Video recording true single-photon double-slit interference

abstract:
  As normally used, no commercially available camera has a low-enough dark
noise to directly produce video recordings of double-slit interference at the
photon-by-photon level, because readout noise significantly contaminates or
overwhelms the signal. In this work, noise levels are significantly reduced by
turning on the camera only when the presence of a photon has been heralded by
the arrival, at an independent detector, of a time-correlated photon produced
via parametric down-conversion. This triggering scheme provides the improvement
required for direct video imaging of Young's double-slit experiment with single
photons, allowing clarified versions of this foundational demonstration.
Further, we introduce variations on this experiment aimed at promoting
discussion of the role spatial coherence plays in such a measurement. We also
emphasize complementary aspects of single-photon measurement, where imaging
yields (transverse) position information, while diffraction yields the
transverse momentum, and highlight the roles of transverse position and
momentum correlations between down-converted photons, including examples of
"ghost" imaging and diffraction. The videos can be accessed at
http://sun.iwu.edu/~gspaldin/SinglePhotonVideos.html online.


title:
Thermodynamic signatures of an underlying quantum phase transition: A
  grand canonical approach

abstract:
  The grand canonical formalism is employed to study the thermodynamic
structure of a model displaying a quantum phase transition when studied with
respect to the canonical formalism. A numerical survey shows that the grand
partition function diverges following a power law when the interaction
parameter approaches a limiting constant. The power-law exponent takes a
distinctive value when such limiting constant coincides with the critical point
of the subjacent quantum phase transition. An approximated expression for the
grand partition function is derived analytically implementing a mean field
scheme and a number of thermodynamic observables are obtained. The system
observables show signatures that can be used to track the critical point of the
underlying transition. This result provides a simple fact that can be exploited
to verify the existence of a quantum phase transition avoiding the zero
temperature regime.


title: Thermodynamics of noncommutative quantum Kerr black holes

abstract:
  Thermodynamic formalism for rotating black holes, characterized by
noncommutative and quantum corrections, is constructed. From a fundamental
thermodynamic relation, equations of state and thermodynamic response functions
are explicitly given and the effect of noncommutativity and quantum correction
is discussed. It is shown that the well known divergence exhibited in specific
heat is not removed by any of these corrections. However, regions of
thermodynamic stability are affected by noncommutativity, increasing the
available states for which some thermodynamic stability conditions are
satisfied.


title: Pl\"ucker Correction Problem: Analysis and Improvements in Efficiency

abstract:
  A given six dimensional vector represents a 3D straight line in Plucker
coordinates if its coordinates satisfy the Klein quadric constraint. In many
problems aiming to find the Plucker coordinates of lines, noise in the data
and other type of errors contribute for obtaining 6D vectors that do not
correspond to lines, because of that constraint. A common procedure to overcome
this drawback is to find the Plucker coordinates of the lines that are closest
to those vectors. This is known as the Plucker correction problem. In this
article we propose a simple, closed-form, and global solution for this problem.
When compared with the state-of-the-art method, one can conclude that our
algorithm is easier and requires much less operations than previous techniques
(it does not require Singular Value Decomposition techniques).


title:
Bounds on the electromagnetic dipole moments through the single top
  production at the CLIC

abstract:
  We obtain bounds on the anomalous magnetic and electric dipole moments of the
$t$-quark from a future high-energy and high-luminosity linear electron
positron collider, such as the CLIC, with unpolarized and polarized electron
beams which are a powerful tool to determine new physics. We consider the
processes $\gamma e^- \to \bar t b\nu_e$ ($\gamma$ is the Compton
backscattering photon) and $e^+e^- \to e^-\gamma^* e^+ \to \bar t b\nu_e e^+$
($\gamma^*$ is the Weizsacker-Williams photon) which are one of the most
important sources of single top quark production. For the systematic
uncertainties of $\delta_{sys}=0\%,\hspace{1mm}5\%$, $b-\mbox{tagging
efficiency}=0.8$, center-of-mass energy of $\sqrt{s}=3\hspace{0.8mm}TeV$,
integrated luminosity of ${\cal L}=2\hspace{0.5mm}ab^{-1}$ and
$2\sigma\hspace{1mm}(3\sigma)$ C.L. the future $e^+e^-$ collider may put bounds
on the electromagnetic dipole moments $\hat a_V$ and $\hat a_A$ of the top
quark of the order of ${\cal O}(10^{-2}-10^{-1})$, which are highly competitive
with those recently reported in previous studies.


title: Geometry and categorification

abstract:
  We describe a number of geometric contexts where categorification appears
naturally: coherent sheaves, constructible sheaves and sheaves of modules over
quantizations. In each case, we discuss how "index formulas" allow us to easily
perform categorical calculations, and readily relate classical constructions of
geometric representation theory to categorical ones.


title:
Time variation in the low frequency spectrum of Vela-like pulsar
  B1800-21

abstract:
  We report the flux measurement of the Vela like pulsar B1800-21 at the low
radio frequency regime over multiple epochs spanning several years. The
spectrum shows a turnover around the GHz frequency range and represents a
typical example of gigahertz-peaked spectrum (GPS) pulsar. Our observations
revealed that the pulsar spectrum show a significant evolution during the
observing period with the low frequency part of the spectrum becoming steeper,
with a higher turnover frequency, for a period of several years before
reverting back to the initial shape during the latest measurements. The
spectral change over times spanning several years requires dense structures,
with free electron densities around 1000--20000 cm$^{-3}$ and physical
dimensions ~220 AU, in the interstellar medium (ISM) traversing across the
pulsar line of sight. We look into the possible sites of such structures in the
ISM and likely mechanisms particularly the thermal free-free absorption as
possible explanations for the change.


title:
Monotonicity and concavity of integral functionals involving area
  measures of convex bodies

abstract:
  For a broad class of integral functionals defined on the space of
$n$-dimensional convex bodies, we establish necessary and sufficient conditions
for monotonicity, and necessary conditions for the validity of a
Brunn-Minkowski type inequality. In particular, we prove that a Brunn-Minkowski
type inequality implies monotonicity, and that a general Brunn-Minkowski type
inequality is equivalent to the functional being a mixed volume.


title:
A discrete data assimilation scheme for the solutions of the 2D
  Navier-Stokes equations and their statistics

abstract:
  We adapt a previously introduced continuous in time data assimilation
(downscaling) algorithm for the 2D Navier-Stokes equations to the more
realistic case when the measurements are obtained discretely in time and may be
contaminated by systematic errors. Our algorithm is designed to work with a
general class of observables, such as low Fourier modes and local spatial
averages over finite volume elements. Under suitable conditions on the
relaxation (nudging) parameter, the spatial mesh resolution and the time step
between successive measurements, we obtain an asymptotic in time estimate of
the difference between the approximating solution and the unknown reference
solution corresponding to the measurements, in an appropriate norm, which shows
exponential convergence up to a term which depends on the size of the errors. A
stationary statistical analysis of our discrete data assimilation algorithm is
also provided.


title:
A Nonparametric Framework for Quantifying Generative Inference on
  Neuromorphic Systems

abstract:
  Restricted Boltzmann Machines and Deep Belief Networks have been successfully
used in probabilistic generative model applications such as image occlusion
removal, pattern completion and motion synthesis. Generative inference in such
algorithms can be performed very efficiently on hardware using a Markov Chain
Monte Carlo procedure called Gibbs sampling, where stochastic samples are drawn
from noisy integrate and fire neurons implemented on neuromorphic substrates.
Currently, no satisfactory metrics exist for evaluating the generative
performance of such algorithms implemented on high-dimensional data for
neuromorphic platforms. This paper demonstrates the application of
nonparametric goodness-of-fit testing to both quantify the generative
performance as well as provide decision-directed criteria for choosing the
parameters of the neuromorphic Gibbs sampler and optimizing usage of hardware
resources used during sampling.


title: Compact objects in Horndeski gravity

abstract:
  Horndeski gravity holds a special position as the most general extension of
Einstein's theory of general relativity with a single scalar degree of freedom
and second-order field equations. Because of these features, Horndeski gravity
is an attractive phenomenological playground to investigate the consequences of
modifications of general relativity in cosmology and astrophysics. We present a
review of the progress made so far in the study of compact objects (black holes
and neutron stars) within Horndeski gravity. In particular, we review our
recent work on slowly rotating black holes and present some new results on
slowly rotating neutron stars.


title: Funding, repo and credit inclusive valuation as modified option pricing

abstract:
  We take the holistic approach of computing an OTC claim value that
incorporates credit and funding liquidity risks and their interplays, instead
of forcing individual price adjustments: CVA, DVA, FVA, KVA. The resulting
nonlinear mathematical problem features semilinear PDEs and FBSDEs. We show
that for the benchmark vulnerable claim there is an analytical solution, and we
express it in terms of the Black-Scholes formula with dividends. This allows
for a detailed valuation analysis, stress testing and risk analysis via
sensitivities.


title:
Temperature-driven massless Kane fermions in HgCdTe crystals:
  verification of universal velocity and rest-mass description

abstract:
  It has recently been shown that the electronic states in bulk gapless HgCdTe
offer another realization of pseudo-relativistic three-dimensional particles in
a condensed matter system. These single valley relativistic states, referred to
as massless Kane fermions, cannot be described by any other well-known
relativistic massless particles. Furthermore, the HgCdTe band structure can be
continuously tailored by modifying either the cadmium content or temperature.
At the critical concentration or temperature, the bandgap, Eg, collapses as the
system undergoes a semimetal-to-semiconductor topological phase transition
between the inverted and normal alignments. Here, using far-infrared
magneto-spectroscopy we explore the continuous evolution of band structure of
bulk HgCdTe as temperature is tuned across the topological phase transition. We
demonstrate that the rest-mass of the Dirac-like Kane fermions, m changes sign
at the critical temperature, while their velocity, c remains constant. The
relation Eg = 2mc2 with the universal value of c = (1.07 +- 0.05)10x6 m/s
remains valid in a broad range of temperatures and Cd concentrations,
indicating a striking universality of the pseudo-relativistic description of
the Dirac-like Kane fermions in HgCdTe.


title:
First Results from the Rapid-Response Spectrophotometric
  Characterization of Near-Earth Objects using UKIRT

abstract:
  Using the Wide Field Camera for the United Kingdom Infrared Telescope, we
measure the near-infrared colors of near-Earth objects (NEOs) in order to put
constraints on their taxonomic classifications. The rapid-response character of
our observations allows us to observe NEOs when they are close to the Earth and
bright. Here we present near-infrared color measurements of 86 NEOs, most of
which were observed within a few days of their discovery, allowing us to
characterize NEOs with diameters of only a few meters. Using machine-learning
methods, we compare our measurements to existing asteroid spectral data and
provide probabilistic taxonomic classifications for our targets. Our
observations allow us to distinguish between S-complex, C/X-complex, D-type,
and V-type asteroids. Our results suggest that the fraction of S-complex
asteroids in the whole NEO population is lower than the fraction of ordinary
chondrites in the meteorite fall statistics. Future data obtained with UKIRT
will be used to investigate the significance of this discrepancy.


title: Symmetry in the Green's function for birth-death chains

abstract:
  A symmetric relation in the probabilistic Green's function for birth-death
chains is explored. Two proofs are given, each of which makes use of the known
symmetry of the Green's functions in other contexts. The first uses as primary
tool the local time of Brownian motion, while the second uses the reciprocity
principle from electric network theory. We also show that the the second proof
extends easily to cover birth-death chains (a.k.a. state-dependent random
walks) on trees.


title: Sum rules for effective resistances in infinite graphs

abstract:
  Extending work of Foster, Doyle, and others, we show how the Foster Theorems,
a family of results concerning effective resistances on finite graphs, can in
certain cases be extended to infinite graphs. A family of sum rules is then
obtained, which allows one to easily calculate the sum of the resistances over
all paths of a given length. The results are illustrated with some of the most
common grids in the plane, including the square, triangular, and hexagonal
grids.


title:
Clifford algebra is the natural framework for root systems and Coxeter
  groups. Group theory: Coxeter, conformal and modular groups

abstract:
  In this paper, we make the case that Clifford algebra is the natural
framework for root systems and reflection groups, as well as related groups
such as the conformal and modular groups: The metric that exists on these
spaces can always be used to construct the corresponding Clifford algebra. Via
the Cartan-Dieudonn\'e theorem all the transformations of interest can be
written as products of reflections and thus via `sandwiching' with Clifford
algebra multivectors. These multivector groups can be used to perform concrete
calculations in different groups, e.g. the various types of polyhedral groups,
and we treat the example of the tetrahedral group $A_3$ in detail. As an aside,
this gives a constructive result that induces from every 3D root system a root
system in dimension four, which hinges on the facts that the group of spinors
provides a double cover of the rotations, the space of 3D spinors has a 4D
euclidean inner product, and with respect to this inner product the group of
spinors can be shown to be closed under reflections. In particular the 4D root
systems/Coxeter groups induced in this way are precisely the exceptional ones,
with the 3D spinorial point of view also explaining their unusual automorphism
groups. This construction simplifies Arnold's trinities and puts the McKay
correspondence into a wider framework. We finally discuss extending the
conformal geometric algebra approach to the 2D conformal and modular groups,
which could have interesting novel applications in conformal field theory,
string theory and modular form theory.


title:
Gate-sensing coherent charge oscillations in a silicon field-effect
  transistor

abstract:
  Quantum mechanical effects induced by the miniaturization of complementary
metal-oxide-semiconductor (CMOS) technology hamper the performance and
scalability prospects of field-effect transistors. However, those quantum
effects, such as tunnelling and coherence, can be harnessed to use existing
CMOS technology for quantum information processing. Here, we report the
observation of coherent charge oscillations in a double quantum dot formed in a
silicon nanowire transistor detected via its dispersive interaction with a
radio-frequency resonant circuit coupled via the gate. Differential capacitance
changes at the inter-dot charge transitions allow us to monitor the state of
the system in the strong-driving regime where we observe the emergence of
Landau-Zener-St{\"u}ckelberg-Majorana interference on the phase response of the
resonator. A theoretical analysis of the dispersive signal demonstrates that
quantum and tunnelling capacitance changes must be included to describe the
qubit-resonator interaction. Furthermore, a Fourier analysis of the
interference pattern reveals a charge coherence time, $T_2\approx 100$~ps. Our
results demonstrate charge coherent control and readout in a simple silicon
transistor and open up the possibility to implement charge and spin qubits in
existing CMOS technology.


title:
Achieving both High Energy Efficiency and High Performance in On-Chip
  Communication using Hierarchical Rings with Deflection Routing

abstract:
  Hierarchical ring networks, which hierarchically connect multiple levels of
rings, have been proposed in the past to improve the scalability of ring
interconnects, but past hierarchical ring designs sacrifice some of the key
benefits of rings by introducing more complex in-ring buffering and buffered
flow control. Our goal in this paper is to design a new hierarchical ring
interconnect that can maintain most of the simplicity of traditional ring
designs (no in-ring buffering or buffered flow control) while achieving high
scalability as more complex buffered hierarchical ring designs. Our design,
called HiRD (Hierarchical Rings with Deflection), includes features that allow
us to mostly maintain the simplicity of traditional simple ring topologies
while providing higher energy efficiency and scalability. First, HiRD does not
have any buffering or buffered flow control within individual rings, and
requires only a small amount of buffering between the ring hierarchy levels.
When inter-ring buffers are full, our design simply deflects flits so that they
circle the ring and try again, which eliminates the need for in-ring buffering.
Second, we introduce two simple mechanisms that provides an end-to-end delivery
guarantee within the entire network without impacting the critical path or
latency of the vast majority of network traffic. HiRD attains equal or better
performance at better energy efficiency than multiple versions of both a
previous hierarchical ring design and a traditional single ring design. We also
analyze our design's characteristics and injection and delivery guarantees. We
conclude that HiRD can be a compelling design point that allows higher energy
efficiency and scalability while retaining the simplicity and appeal of
conventional ring-based designs.


title:
On a Class of Almost Difference Sets Constructed by Using the
  Ding-Helleseth-Martinsens Constructions

abstract:
  Pseudorandom binary sequences with optimal balance and autocorrelation have
many applications in stream cipher, communication, coding theory, etc. It is
known that binary sequences with three-level autocorrelation should have an
almost difference set as their characteristic sets. How to construct new
families of almost difference set is an important research topic in such fields
as communication, coding theory and cryptography. In a work of Ding, Helleseth,
and Martinsen in 2001, the authors developed a new method, known as the
Ding-Helleseth-Martinsens Constructions in literature, of constructing an
almost difference set from product sets of GF(2) and the union of two
cyclotomic classes of order four. In the present paper, we have constructed two
classes of almost difference set with product sets between GF(2) and union sets
of the cyclotomic classes of order 12 using that method. In addition, we could
find there do not exist the Ding-Helleseth-Martinsens Constructions for the
cyclotomic classes of order six and eight.


title:
On the Nonexistence of the Ding-Helleseth-Martinsens Constructions of
  Almost Difference Set for Cyclotomic Classes of Order 6

abstract:
  Pseudorandom sequences with optimal three-level autocorrelation have
important applications in CDMA communication systems. Constructing the
sequences with three-level autocorrelation is equivalent to finding cyclic
almost difference sets as their supports. In a paper of Ding, Helleseth, and
Martinsen, the authors developed a new method known as the
Ding-Helleseth-Martinsens Constructions in literature to construct the almost
difference set using product set between GF(2) and union sets of cyclotomic
classes of order 4. In this correspondence, we show that there do not exist
such constructions for cyclotomic classes of order 6.


title: On the asymptotic behavior of Bergman kernels for positive line bundles

abstract:
  Let L be a positive line bundle on a projective complex manifold. We study
the asymptotic behavior of Bergman kernels associated with the tensor powers
L^p of L as p tends to infinity. The emphasis is the dependence of the uniform
estimates on the positivity of the Chern form of the metric on L. This
situation appears naturally when we approximate a semi-positive singular metric
by smooth positively curved metrics.


title: Hardware Architecture of Complex K-best MIMO Decoder

abstract:
  This paper presents a hardware architecture of complex K-best Multiple Input
Multiple Output (MIMO) decoder reducing the complexity of Maximum Likelihood
(ML) detector. We develop a novel low-power VLSI design of complex K-best
decoder for 8x8 MIMO and 64 QAM modulation scheme. Use of Schnorr-Euchner (SE)
enumeration and a new parameter, Rlimit in the design reduce the complexity of
calculating K-best nodes to a certain level with increased performance. The
total word length of only 16 bits has been adopted for the hardware design
limiting the bit error rate (BER) degradation to 0.3 dB with list size, K and
Rlimit equal to 4. The proposed VLSI architecture is modeled in Verilog HDL
using Xilinx and synthesized using Synopsys Design Vision in 45 nm CMOS
technology. According to the synthesize result, it achieves 1090.8 Mbps
throughput with power consumption of 782 mW and latency of 0.044 us. The
maximum frequency the design proposed is 181.8 MHz.


title:
Discovery of an unusual bright eclipsing binary with the longest known
  period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8

abstract:
  We report on the MASTER Global Robotic Net discovery of an eclipsing binary,
MASTER OT J095310.04+335352.8, previously known as unremarkable star TYC
2505-672-1, which displays extreme orbital parameters. The orbital period
P=69.1 yr is more than 2.5 times longer than that of epsilon-Aurigae, which is
the previous record holder. The light curve is characterized by an extremely
deep total eclipse with a depth of more than 4.5 mag, which is symmetrically
shaped and has a total duration of 3.5 yrs. The eclipse is essentially gray.
The spectra acquired with the Russian 6 m BTA telescope both at minimum and
maximum light mainly correspond to an M0-1III--type red giant, but the spectra
taken at the bottom of eclipse show small traces of a sufficiently hot source.
The observed properties of this system can be better explained as the red giant
eclipsed by a large cloud (the disk) of small particles surrounding the
invisible secondary companion.


title: Versatile and widely tunable mid-infrared erbium doped ZBLAN fiber laser

abstract:
  We report on a long wavelength emitting rare earth doped fiber laser with
emission centered at 3.5 {\mu}m and tunable across 450 nm. The longest
wavelength emission was 3.78 {\mu}m, which is the longest emission from a fiber
laser operating at room temperature. In a simple optical arrangement employing
dielectric mirrors for feedback, the laser was capable of emitting 1.45 W of
near diffraction limited output power at 3.47 {\mu}m. These emission
characteristics compliment the emission from quantum cascade lasers and
demonstrate how all infrared dual wavelength pumping can be used to access high
lying rare earth ion transitions that have previously relied on visible
wavelength pumping.


title: PSPACE-Complete Two-Color Placement Games

abstract:
  We show that three placement games, Col, NoGo, and Fjords, are
PSPACE-complete on planar graphs. The hardness of Col and Fjords is shown via a
reduction from Bounded 2-Player Constraint Logic and NoGo is shown to be hard
directly from Col.


title: The dispersion of period spacing for DAV stars

abstract:
  Three groups of DAV star models are evolved with time-dependent element
diffusion by \texttt{WDEC}. The core compositions of these models are directly
from white dwarf models evolved by \texttt{MESA}, which are results of
thermonuclear burning. Based on these DAV star models, we try to study the
dispersion of period spacing. The thickness of hydrogen atmosphere can
seriously affect the deviation degree of minimal period spacings. The minimal
period spacings dominate the dispersion of period spacing. The thinner the
hydrogen atmosphere, basically, the more dispersive the period spacing.
Standard deviations are used to analyze the dispersion of period spacing.
Studying the dispersion of period spacing on a DAV star KUV03442+0719
preliminarily, we suggest that log($M_{\rm H}/M_{*}$) is from -8.5 to -5.5. In
addition, modes partly trapped in C/O core are found based on those DAV star
models. The identified modes and average period spacings indicate that
KUV03442+0719 may be the first star to 'observe' modes partly trapped in C/O
core.


title:
Particles inside Electrolytes with Ion-specific Interactions, Their
  Effective Charge Distributions and Effective Interactions

abstract:
  In this work, we explore the statistical physics of colloidal particles that
interact with electrolytes via ion-specific interactions. Firstly we study
particles interact weakly with electrolyte using linear response theory. We
find that the mean potential around a particle is linearly determined by the
{\em effective charge distribution} of the particle, which depends both on the
bare charge distribution and on ion-specific interactions. We also discuss the
effective interaction between two such particles and show that, in far field
regime, it is bilinear in the effective charge distributions of two particles.
We subsequently generalize the above results to the more complicated case where
particles interact strongly with the electrolyte. Our results indicate that in
order to understand the statistical physics of non-dilute electrolytes, both
ion-specific interactions and ionic correlations have to be addressed in a
single unified and consistent framework.


title:
Study of Aqueous Dispersions of Magnetic Nanoparticles by Magnetic and
  Rheological Measurements

abstract:
  The observed magnetic tunability of light transmission through a ferrofluid
can be effectively understood in terms of the inter-particle interaction that
can be estimated from the magnetic and rheological properties of these fluids.
The present study reports complementary magnetic and rheological measurements
of aqueous dispersions of ferrite nanoparticles and a commercial ferrofluid.
The room temperature magnetization measured in a SQUID magnetometer up to
fields of 1 to 2 Tesla showed superparamagnetic behaviour of the particles and
the dispersion with the background signal of the liquid showing a diamagnetic
behaviour. The room temperature rheological behaviour in zero magnetic field of
the fluids was investigated by measuring the viscosity as a function of shear
rate from 1-100 s-1. The particle size and the nature of the carrier liquid
determine the viscosity and is expected to have an effect on the inter-particle
interaction.


title:
Prospects of Passive Radio Detection of a Subsurface Ocean on Europa
  with a Lander

abstract:
  We estimate the sensitivity of a lander-based instrument for the passive
radio detection of a subsurface ocean beneath the ice shell of Europa, expected
to be between 3~km - 30~km thick, using Jupiter's decametric radiation. A
passive technique was previously studied for an orbiter. Using passive
detection in a lander platform provides a point measurement with significant
improvements due to largely reduced losses from surface roughness effects,
longer integration times, and diminished dispersion due to ionospheric effects
allowing operation at lower frequencies and a wider band. A passive sounder
on-board a lander provides a low resource instrument sensitive to subsurface
ocean at Europa up to depths of 6.9~km for high loss ice (16 dB/km two-way
attenuation rate) and 69~km for pure ice (1.6 dB/km).


title: On a generalization of the Gauss's formula

abstract:
  In this paper we study a group theoretical generalization of the well-known
Gauss's formula that uses the generalized Euler's totient function introduced
in [11].


title: A characterization of PSL(2,q), q = 5,7

abstract:
  In this short note we prove that the finite non-abelian simple groups
PSL(2,q), where q = 5,7, are determined by their posets of classes of
isomorphic subgroups. In particular, this disproves the conjecture in the end
of [5].


title:
Unraveling nonadiabatic ionization and Coulomb potential effects in
  strong-field photoelectron holography

abstract:
  Strong field photoelectron holography has been proposed as a means for
interrogating the spatial and temporal information of electrons and ions in a
dynamic system. After ionization, part of the electron wave packet may directly
go to the detector (the reference wave), while another part may be driven back
to the ion where it scatters off (the signal wave). The interference hologram
of the two waves may be used to retrieve the target information. However,
unlike conventional optical holography, the propagations of electron wave
packets are affected by the Coulomb potential as well as by the laser field. In
addition, electrons are emitted over the whole laser pulse duration, thus
multiple interferences may occur. In this work, we used a generalized
quantum-trajectory Monte Carlo method to investigate the effect of Coulomb
potential and the nonadiabatic subcycle ionization on the photoelectron
hologram. We showed that photoelectron hologram can be well described only when
the nonadiabatic effect in ionization is accounted for, and Coulomb potential
can be neglected only in the tunnel ionization regime. Our results help
establishing photoelectron holography for probing spatial and dynamic
properties of atoms and molecules.


title:
Broadband wide-angle absorption enhancement due to mode conversion in
  cold unmagnetized plasmas with periodic density variations

abstract:
  We study theoretically the mode conversion and the associated resonant
absorption of p-polarized electromagnetic waves into longitudinal plasma
oscillations in cold, unmagnetized and stratified plasmas with periodic spatial
density variations. We consider sinusoidal density configurations for which the
frequency band where mode conversion occurs is well included within a
transmission band of the one-dimensional plasma photonic crystal. We calculate
the mode conversion coefficient, which measures the fraction of the
electromagnetic wave energy absorbed into the plasma, and the spatial
distribution of the magnetic field intensity for various values of the wave
frequency and the incident angle using the invariant imbedding theory of mode
conversion. We find that the absorption is greatly enhanced over a wide range
of frequency and incident angle due to the interplay between the mode
conversion and the photonic band structure. The enhancement occurs because for
frequencies within a transmission band, the wave reflection is strongly
suppressed and the waves penetrate more deeply into the inhomogeneous region,
thereby increasing the possibility for them to reach many resonance points
where the dielectric permittivity vanishes.


title:
The stability of 3 transmembrane and 4 transmembrane human vitamin K
  epoxide reductase models

abstract:
  3 transmembrane and 4 transmembrane helices models are suggested for the
human vitamin K epoxide reductase (VKOR). In this study, we investigate the
stability of the human 3 transmembrane/4 transmembrane VKOR models employing a
coarse-grained normal mode analysis and molecular dynamics simulation. Based on
the analysis of the mobility of each transmembrane domain, we suggest that the
3 transmembrane human VKOR model is more stable than the 4 transmembrane human
VKOR model.


title:
Resonant absorption and amplification of circularly-polarized waves in
  inhomogeneous chiral media

abstract:
  It has been found that in the media where the dielectric permittivity
$\epsilon$ or the magnetic permeability $\mu$ is near zero and in transition
metamaterials where $\epsilon$ or $\mu$ changes from positive to negative
values, there occur a strong absorption or amplification of the electromagnetic
wave energy in the presence of an infinitesimally small damping or gain and a
strong enhancement of the electromagnetic fields. We attribute these phenomena
to the mode conversion of transverse electromagnetic waves into longitudinal
plasma oscillations and its inverse process. In this paper, we study analogous
phenomena occurring in chiral media theoretically using the invariant imbedding
method. In uniform isotropic chiral media, right-circularly-polarized and
left-circularly-polarized waves are the eigenmodes of propagation with
different effective refractive indices $n_+$ and $n_-$, whereas in the chiral
media with a nonuniform impedance variation, they are no longer the eigenmodes
and are coupled to each other. We find that both in uniform chiral slabs where
either $n_+$ or $n_-$ is near zero and in chiral transition metamaterials where
$n_+$ or $n_-$ changes from positive to negative values, a strong absorption or
amplification of circularly-polarized waves occurs in the presence of an
infinitesimally small damping or gain. We present detailed calculations of the
mode conversion coefficient, which measures the fraction of the electromagnetic
wave energy absorbed into the medium, for various configurations of $\epsilon$
and $\mu$ with an emphasis on the influence of a nonuniform impedance. We
propose possible applications of these phenomena to linear and nonlinear
optical devices that react selectively to the helicity of the circular
polarization.


title:
Abstractive Text Summarization Using Sequence-to-Sequence RNNs and
  Beyond

abstract:
  In this work, we model abstractive text summarization using Attentional
Encoder-Decoder Recurrent Neural Networks, and show that they achieve
state-of-the-art performance on two different corpora. We propose several novel
models that address critical problems in summarization that are not adequately
modeled by the basic architecture, such as modeling key-words, capturing the
hierarchy of sentence-to-word structure, and emitting words that are rare or
unseen at training time. Our work shows that many of our proposed models
contribute to further improvement in performance. We also propose a new dataset
consisting of multi-sentence summaries, and establish performance benchmarks
for further research.


title:
Chiral Primordial Gravitational Waves from Dilaton Induced Delayed
  Chromo-natural Inflation

abstract:
  We study inflation driven by a dilaton and an axion, both of which are
coupled to a SU(2) gauge field. We find that the inflation driven by the
dilaton occurs in the early stage of inflation during which the gauge field
grows due to the gauge kinetic function. When the energy density of magnetic
fields catches up with that of electric fields, chromo-natural inflation takes
over in the late stage of inflation, which we call delayed chromo-natural
inflation. Thus, the delayed chromo-natural inflation driven by the axion and
the gauge field is induced by the dilaton. The interesting outcome of the model
is generation of chiral primordial gravitational waves on small scales. Since
the gauge field is inert in the early stage of inflation, it is viable in
contrast to the conventinal chromo-natural inflation. We find the parameter
region where chiral gravitational waves are generated in a frequency range
higher than nHz, which are potentially detectable in future gravitational wave
interferometers and pulsar timing arrays such as DECIGO, eLISA and SKA.


title: Spectral Learning for Supervised Topic Models

abstract:
  Supervised topic models simultaneously model the latent topic structure of
large collections of documents and a response variable associated with each
document. Existing inference methods are based on variational approximation or
Monte Carlo sampling, which often suffers from the local minimum defect.
Spectral methods have been applied to learn unsupervised topic models, such as
latent Dirichlet allocation (LDA), with provable guarantees. This paper
investigates the possibility of applying spectral methods to recover the
parameters of supervised LDA (sLDA). We first present a two-stage spectral
method, which recovers the parameters of LDA followed by a power update method
to recover the regression model parameters. Then, we further present a
single-phase spectral algorithm to jointly recover the topic distribution
matrix as well as the regression weights. Our spectral algorithms are provably
correct and computationally efficient. We prove a sample complexity bound for
each algorithm and subsequently derive a sufficient condition for the
identifiability of sLDA. Thorough experiments on synthetic and real-world
datasets verify the theory and demonstrate the practical effectiveness of the
spectral algorithms. In fact, our results on a large-scale review rating
dataset demonstrate that our single-phase spectral algorithm alone gets
comparable or even better performance than state-of-the-art methods, while
previous work on spectral methods has rarely reported such promising
performance.


title: One-parameter deformations of the diassociative and dendriform operads

abstract:
  Livernet and Loday constructed a polarization of the nonsymmetric associative
operad A with one operation into a symmetric operad SA with two operations (the
Lie bracket and Jordan product), and defined a one-parameter deformation of SA
which includes Poisson algebras. We combine this with the dendriform splitting
of an associative operation into the sum of two nonassociative operations, and
use Koszul duality for quadratic operads, to construct one-parameter
deformations of the nonsymmetric dendriform and diassociative operads into the
category of symmetric operads.


title:
Form Factors and Generalized Parton Distributions in Basis Light-Front
  Quantization

abstract:
  We calculate the elastic form factors and the Generalized Parton
Distributions (GPDs) for four low-lying bound states of a demonstration
fermion-antifermion system, strong coupling positronium ($e \bar{e}$), using
Basis Light-Front Quantization (BLFQ). Using this approach, we also calculate
the impact-parameter dependent GPDs $q(x, {\vec b_\perp})$ to visualize the
fermion density in the transverse plane (${\vec b_\perp}$). We compare selected
results with corresponding quantities in the non-relativistic limit to reveal
relativistic effects. Our results establish the foundation within BLFQ for
investigating the form factors and the GPDs for hadronic systems.


title: Generalized Gaussian Mechanism for Differential Privacy

abstract:
  Assessment of disclosure risk is of paramount importance in the research and
applications of data privacy techniques. The concept of differential privacy
(DP) formalizes privacy in probabilistic terms and provides a robust concept
for privacy protection without making assumptions about the background
knowledge of adversaries. Practical applications of DP involve development of
DP mechanisms to release results at a pre-specified privacy budget. In this
paper, we generalize the widely used Laplace mechanism to the family of
generalized Gaussian (GG) mechanism based on the $l_p$ global sensitivity of
statistical queries. We explore the theoretical requirement for the GG
mechanism to reach DP at prespecified privacy parameters, and investigate the
connections and differences between the GG mechanism and the Exponential
mechanism based on the GG distribution We also present a lower bound on the
scale parameter of the Gaussian mechanism of $(\epsilon,\delta)$-probabilistic
DP as a special case of the GG mechanism, and compare the statistical utility
of the sanitized results in the tail probability and dispersion in the Gaussian
and Laplace mechanisms. Lastly, we apply the GG mechanism in 3 experiments (the
mildew, Czech, adult data), and compare the accuracy of sanitized results via
the $l_1$ distance and Kullback-Leibler divergence and examine how sanitization
affects the prediction power of a classifier constructed with the sanitized
data in the adult experiment.


title: Tunable electron-electron interactions in LaAlO3/SrTiO3 nanostructures

abstract:
  The interface between the two complex oxides LaAlO3 and SrTiO3 has remarkable
properties that can be locally reconfigured between conducting and insulating
states using a conductive atomic force microscope. Prior investigations of
sketched quantum dot devices revealed a phase in which electrons form pairs,
implying a strongly attractive electron-electron interaction. Here, we show
that these devices with strong electron-electron interactions can exhibit a
gate-tunable transition from a pair-tunneling regime to a single-electron
(Andreev bound state) tunneling regime where the interactions become repulsive.
The electron-electron interaction sign change is associated with a Lifshitz
transition where the dxz and dyz bands start to become occupied. This
electronically tunable electron-electron interaction, combined with the
nanoscale reconfigurability of this system, provides an interesting starting
point towards solid-state quantum simulation.


title:
Sampling latent states for high-dimensional non-linear state space
  models with the embedded HMM method

abstract:
  We propose a new scheme for selecting pool states for the embedded Hidden
Markov Model (HMM) Markov Chain Monte Carlo (MCMC) method. This new scheme
allows the embedded HMM method to be used for efficient sampling in state space
models where the state can be high-dimensional. Previously, embedded HMM
methods were only applied to models with a one-dimensional state space. We
demonstrate that using our proposed pool state selection scheme, an embedded
HMM sampler can have similar performance to a well-tuned sampler that uses a
combination of Particle Gibbs with Backward Sampling (PGBS) and Metropolis
updates. The scaling to higher dimensions is made possible by selecting pool
states locally near the current value of the state sequence. The proposed pool
state selection scheme also allows each iteration of the embedded HMM sampler
to take time linear in the number of the pool states, as opposed to quadratic
as in the original embedded HMM sampler. We also consider a model with a
multimodal posterior, and show how a technique we term "mirroring" can be used
to efficiently move between the modes.


title: On critical exponents of a $k$-Hessian equation in the whole space

abstract:
  In this paper, we study negative classical solutions and stable solutions of
the following $k$-Hessian equation $$ F_k(D^2V)=(-V)^p \quad in~R^n $$ with
radial structure, where $n \geq 3$, $1<k<n/2$ and $p>1$. This equation is
related to the extremal functions of the Hessian Sobolev inequality on the
whole space. Several critical exponents including the Serrin type, the Sobolev
type, and the Joseph-Lundgren type, play key roles in studying existence and
decay rates. We believe that these critical exponents still come into play to
research $k$-Hessian equations without radial structure.


title:
Large deviation statistics of non-equilibrium fluctuations in a sheared
  model-fluid

abstract:
  We analyse the statistics of the shear stress in a one dimensional
\emph{model fluid}, that exhibits a rich phase behaviour akin to real complex
fluids under shear. We show that the energy flux satisfies the Gallavotti-Cohen
FT across all phases in the system. The theorem allows us to define an
effective temperature which deviates considerably from the equilibrium
temperature as the noise in the system increases. This deviation is negligible
when the system size is small. The dependence of the effective temperature on
the strain rate is phase-dependent. It doesn't vary much at the phase
boundaries. The effective temperature can also be determined from the large
deviation function of the energy flux. The local strain rate statistics obeys
the large deviation principle and satisfies a fluctuation relation. It does not
exhibit a distinct kink near zero strain rate because of inertia of the rotors
in our system.


title:
Expecting to be HIP: Hawkes Intensity Processes for Social Media
  Popularity

abstract:
  Modeling and predicting the popularity of online content is a significant
problem for the practice of information dissemination, advertising, and
consumption. Recent work analyzing massive datasets advances our understanding
of popularity, but one major gap remains: To precisely quantify the
relationship between the popularity of an online item and the external
promotions it receives. This work supplies the missing link between exogenous
inputs from public social media platforms, such as Twitter, and endogenous
responses within the content platform, such as YouTube. We develop a novel
mathematical model, the Hawkes intensity process, which can explain the complex
popularity history of each video according to its type of content, network of
diffusion, and sensitivity to promotion. Our model supplies a prototypical
description of videos, called an endo-exo map. This map explains popularity as
the result of an extrinsic factor - the amount of promotions from the outside
world that the video receives, acting upon two intrinsic factors - sensitivity
to promotion, and inherent virality. We use this model to forecast future
popularity given promotions on a large 5-months feed of the most-tweeted
videos, and found it to lower the average error by 28.6% from approaches based
on popularity history. Finally, we can identify videos that have a high
potential to become viral, as well as those for which promotions will have
hardly any effect.


title:
Search for single production of a vector-like quark via a heavy gluon in
  the $4b$ final state with the ATLAS detector in $pp$ collisions at $\sqrt{s}
  = 8$ TeV

abstract:
  A search is performed for the process $pp \to G^* \to B_H\bar b/\bar B_H b
\to H b \bar b \to b\bar bb\bar b$, predicted in composite Higgs scenarios,
where $G^*$ is a heavy colour octet vector resonance and $B_H$ a vector-like
quark of charge $-1/3$. The data were obtained from $pp$ collisions at a
centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of
19.5 fb$^{-1}$, recorded by the ATLAS detector at the LHC. The largest
background, multijet production, is estimated using a data-driven method. No
significant excess of events with respect to Standard Model predictions is
observed, and upper limits on the production cross section times branching
ratio are set. Comparisons to the predictions from a specific benchmark model
are made, resulting in lower mass limits in the two-dimensional mass plane of
$m_{G^*}$ vs. $m_{B_H}$.


title:
Hawking Radiation as a Probe for the Interior Structure of Regular Black
  Holes

abstract:
  The notion of the black hole singularity and the proof of the singularity
theorem were considered great successes in classical general relativity.
Singularities had presented deep puzzles to physicists. Conceptual challenges
were set up by the intractability of the singularity. The existence of black
hole horizons which cover up the interior, including the singularity of the
black hole from outside observers, builds an information curtain, further
hindering physicists from understanding the nature of the singularity and the
interior structure of black holes. The regular black hole is a concept produced
out of multiple attempts of establishing a tractable and understandable
interior structure for black hole as well as avoiding the singularity behind
the black hole horizon. A method is needed to check the correctness of the new
constructions of black holes. After studying the Hawking radiation by fermion
tunnelling from one type of regular black hole, structure dependent results
were obtained. The result being structure dependent points out the prospects of
employing the Hawking radiation as a method to probe into the structure of
black holes.


title:
Methane Incorporation into Liquid Fuel by Non-Equilibrium Plasma
  Discharges

abstract:
  The conventional ways of processing natural gas into more efficient and
economical fuels usually either have low conversion rate or low energy
efficiency. In this work, a new approach of methane liquefaction is proposed.
Instead of direct treatment of only natural gas, plasma activated methane is
reacting with liquid fuel. In this way, methane molecules are directly
incorporated onto liquid fuel to achieve liquefaction. Nanosecond-pulsed
dielectric barrier discharge and atmospheric pressure glow discharge are used
here to ensure no local heating in gas bubbles. Effects of both discharges on
methane reaction with liquid fuel are investigated, mass and chemical changes
in liquid are observed. Preliminary results show fixation of methane in liquid
fuel.


title: Quark number holonomy and confinement-deconfinement transition

abstract:
  We propose a new quantity which describes the confinement-deconfinement
transition based on topological properties of QCD. The quantity which we call
the quark number holonomy is defined as the integral of the quark number
susceptibility along the closed loop of $\theta$ where $\theta$ is the
dimensionless imaginary chemical potential. Expected behavior of the quark
number holonomy at finite temperature is discussed and its asymptotic behaviors
are shown.


title:
Automatic Generation of High-Coverage Tests for RTL Designs using
  Software Techniques and Tools

abstract:
  Register Transfer Level (RTL) design validation is a crucial stage in the
hardware design process. We present a new approach to enhancing RTL design
validation using available software techniques and tools. Our approach converts
the source code of a RTL design into a C++ software program. Then a powerful
symbolic execution engine is employed to execute the converted C++ program
symbolically to generate test cases. To better generate efficient test cases,
we limit the number of cycles to guide symbolic execution. Moreover, we add
bit-level symbolic variable support into the symbolic execution engine.
Generated test cases are further evaluated by simulating the RTL design to get
accurate coverage. We have evaluated the approach on a floating point unit
(FPU) design. The preliminary results show that our approach can deliver
high-quality tests to achieve high coverage.


title: A groupoidification of the fermion algebra

abstract:
  In this paper, we consider the groupoidification of the fermion algebra. We
construct a groupoid as the categorical analogues of the fermionic Fock space,
and the creation and annihilation operators correspond to spans of groupoids.
The categorical fermionic Fock states have some extra structures comparing with
the normal forms. We also construct a 2-category of spans of groupoids
corresponding to the fermion algebra. The relations of the morphisms in this
2-category are consistent with those in the graphical category which is
represented by string diagrams.


title: The geometry of homothetic covering and illumination

abstract:
  At a first glance, the problem of illuminating the boundary of a convex body
by external light sources and the problem of covering a convex body by its
smaller positive homothetic copies appear to be quite different. They are in
fact two sides of the same coin and give rise to one of the important
longstanding open problems in discrete geometry, namely, the Illumination
Conjecture. In this paper, we survey the activity in the areas of discrete
geometry, computational geometry and geometric analysis motivated by this
conjecture. Special care is taken to include the recent advances that are not
covered by the existing surveys. We also include some of our recent results
related to these problems and describe two new approaches -- one conventional
and the other computer-assisted -- to make progress on the illumination
problem. Some open problems and conjectures are also presented.


title: Determination of intrinsic lifetime of edge magnetoplasmons

abstract:
  It is known that peculiar plasmons whose frequencies are purely imaginary
exist in the interior of a two-dimensional electronic system described by the
Drude model. We show that when an external magnetic field is applied to the
system, these bulk plasmons are still non-oscillating and are isolated from the
magnetoplasmons by the energy gap of the cyclotron frequency. These are mainly
in a transverse magnetic mode and can combine with a transverse electronic mode
locally at an edge of the system to form edge magnetoplasmons. With this
observation, we reveal the intrinsic long lifetime of edge magnetoplasmons for
the first time.


title: Structured Sparse Regression via Greedy Hard-Thresholding

abstract:
  Several learning applications require solving high-dimensional regression
problems where the relevant features belong to a small number of (overlapping)
groups. For very large datasets and under standard sparsity constraints, hard
thresholding methods have proven to be extremely efficient, but such methods
require NP hard projections when dealing with overlapping groups. In this
paper, we show that such NP-hard projections can not only be avoided by
appealing to submodular optimization, but such methods come with strong
theoretical guarantees even in the presence of poorly conditioned data (i.e.
say when two features have correlation $\geq 0.99$), which existing analyses
cannot handle. These methods exhibit an interesting computation-accuracy
trade-off and can be extended to significantly harder problems such as sparse
overlapping groups. Experiments on both real and synthetic data validate our
claims and demonstrate that the proposed methods are orders of magnitude faster
than other greedy and convex relaxation techniques for learning with
group-structured sparsity.


title:
De Morgan Dual Nominal Quantifiers Modelling Private Names in
  Non-Commutative Logic

abstract:
  This paper explores the proof theory necessary for recommending an expressive
but decidable first-order system, named MAV1, featuring a de Morgan dual pair
of nominal quantifiers. These nominal quantifiers called `new' and `wen' are
distinct from the self-dual Gabbay-Pitts and Miller-Tiu nominal quantifiers.
The novelty of these nominal quantifiers is they are polarised in the sense
that `new' distributes over positive operators while `wen' distributes over
negative operators. This greater control of bookkeeping enables private names
to be modelled in processes embedded as formulae in MAV1. The technical
challenge is to establish a cut elimination result, from which essential
properties including the transitivity of implication follow. Since the system
is defined using the calculus of structures, a generalisation of the sequent
calculus, novel techniques are employed. The proof relies on an intricately
designed multiset-based measure of the size of a proof, which is used to guide
a normalisation technique called splitting. The presence of equivariance, which
swaps successive quantifiers, induces complex inter-dependencies between
nominal quantifiers, additive conjunction and multiplicative operators in the
proof of splitting. Every rule is justified by an example demonstrating why the
rule is necessary for soundly embedding processes and ensuring that cut
elimination holds.


title:
A Plane-Parallel Wind Solution For Testing Numerical Simulations of
  Photoevaporation

abstract:
  Here we derive a Parker-wind like solution for a stratified, plane-parallel
atmosphere undergoing photoionisation. The difference compared to the standard
Parker solar wind is that the sonic point is crossed only at infinity. The
simplicity of the analytic solution makes it a convenient test problem for
numerical simulations of photoevaporation in protoplanetary discs.


title: Programmable Packet Scheduling

abstract:
  Switches today provide a small set of scheduling algorithms. While we can
tweak scheduling parameters, we cannot modify algorithmic logic, or add a
completely new algorithm, after the switch has been designed. This paper
presents a design for a programmable packet scheduler, which allows scheduling
algorithms---potentially algorithms that are unknown today---to be programmed
into a switch without requiring hardware redesign.
  Our design builds on the observation that scheduling algorithms make two
decisions: in what order to schedule packets and when to schedule them.
Further, in many scheduling algorithms these decisions can be made when packets
are enqueued. We leverage this observation to build a programmable scheduler
using a single abstraction: the push-in first-out queue (PIFO), a priority
queue that maintains the scheduling order and time for such algorithms.
  We show that a programmable scheduler using PIFOs lets us program a wide
variety of scheduling algorithms. We present a detailed hardware design for
this scheduler for a 64-port 10 Gbit/s shared-memory switch with <4% chip area
overhead on a 16-nm standard-cell library. Our design lets us program many
sophisticated algorithms, such as a 5-level hierarchical scheduler with
programmable scheduling algorithms at each level.


title:
Spin-conserving and reversing photoemission from the surface states of
  Bi$_2$Se$_3$ and Au (111)

abstract:
  We present a theory based on first-principles calculations explaining (i) why
the tunability of spin polarizations of photoelectrons from Bi$_2$Se$_3$ (111)
depends on the band index and Bloch wavevector of the surface state and (ii)
why such tunability is absent in the case of isosymmetric Au (111). The results
provide not only an explanation for the recent, puzzling experimental
observations but also a guide toward making highly-tunable spin-polarized
electron sources from topological insulators.


title: Classification of spin and multipolar squeezing

abstract:
  We investigate various types of squeezing in a collective su(2J+1) system
consisting of spin-J particles (J>1/2). We show that the squeezing in the
collective su(2J+1) system can be classified into unitary equivalence classes,
each of which is characterized by a set of squeezed and anti-squeezed
observables forming an su(2) subalgebra in the su(2J+1) algebra. The
dimensionality of the unitary equivalence class is fundamentally related to its
squeezing limit. We also demonstrate the classification of the squeezing among
the spin and multipolar observables in a collective su(4) system.


title: Non-local games and optimal steering at the boundary of the quantum set

abstract:
  The boundary between classical and quantum correlations is well characterised
by linear constraints called Bell inequalities. It is much harder to
characterise the boundary of the quantum set itself in the space of
no-signaling correlations. For the points on the quantum boundary that violate
maximally some Bell inequalities, Oppenheim and Wehner [Science 330, 1072
(2010)] pointed out a complex property: the optimal measurements of Alice steer
Bob's local state to the eigenstate of an effective operator corresponding to
its maximal eigenvalue. This effective operator is the linear combination of
Bob's local operators induced by the coefficients of the Bell inequality, and
it can be interpreted as defining a fine-grained uncertainty relation. It is
natural to ask whether the same property holds for other points on the quantum
boundary, using the Bell expression that defines the tangent hyperplane at each
point. We prove that this is indeed the case for a large set of points,
including some that were believed to provide counterexamples. The price to pay
is to acknowledge that the Oppenheim-Wehner criterion does not respect
equivalence under the no-signaling constraint: for each point, one has to look
for specific forms of writing the Bell expressions.