  We study zCOSMOS-bright optical spectra for 609 Spitzer/MIPS 24
micron-selected galaxies with S(24um)> 0.30 mJy and I<22.5 (AB mag) over 1.5
sq. deg. of the COSMOS field. From emission-line diagnostics we find that: 1)
star-formation rates (SFR) derived from the observed Halpha and Hbeta lines
underestimate, on average, the total SFR by factors ~5 and 10, respectively; 2)
both the Calzetti et al. and the Milky Way reddening laws are suitable to
describe the extinction observed in infrared (IR) sources in most cases; 3)
some IR galaxies at z<0.3 have low abundances, but many others with similar IR
luminosities and redshifts are chemically enriched; 4) The average [OIII]/Hbeta
ratios of nuLnu(24um)>10^11 Lsun galaxies at 0.6<z<0.7 are ~0.6 dex higher than
the average ratio of all zCOSMOS galaxies at similar redshifts. Massive star
formation and active galactic nuclei (AGN) could simultaneously be present in
those galaxies with the highest ionising fluxes; 5) ~1/3 of the galaxies with
metallicity measurements at 0.5<z<0.7 lie below the general mass-metallicity
relation at the corresponding redshifts. The strengths of the 4000 Angstrom
break and the Hdelta EW of our galaxies show that secondary bursts of star
formation are needed to explain the spectral properties of most IR sources. The
LIRG and ULIRG phases occur, on average, between 10^7 and 10^8 years after the
onset of a starburst on top of underlying older stellar populations. These
results are valid for galaxies of different IR luminosities at 0.6<z<1.0 and
seem independent of the mechanisms triggering star formation.


  In this paper, we compute the dual $F$-signatures of certain toric rings by
using combinatorial techniques. Specifically, we calculate the dual
$F$-signatures of Veronese subrings of polynomial rings. Moreover, we give an
upper bound for the dual $F$-signatures of Segre products of polynomial rings
and show that this upper bound is attained in some cases.


  Reminiscent of the parity function in network coding for the butterfly
network, it is shown that forwarding an even/odd indicator bit for a scalar
quantization of a relay observation recovers 1 bit of information at the two
destinations in a noiseless interference channel where interference is treated
as noise. Based on this observation, a coding strategy is proposed to improve
the rate of both users at the same time using a relay node in an interference
channel. In this strategy, the relay observes a linear combination of the two
source signals, and broadcasts a common message to the two destinations over a
shared out-of-band link of rate R0 bits per channel use. The relay message
consists of the bin index of a structured binning scheme obtained from a
2^R0-way partition of the squared lattice in the complex plane. We show that
such scalar quantization-binning relay strategy asymptotically achieves the
cut-set bound in an interference channel with a common out-of-band relay link
of limited rate, improving the sum rate by two bits for every bit relayed,
asymptotically at high signal to noise ratios (SNR) and when interference is
treated as noise. We then use low-density parity-check (LDPC) codes along with
bit-interleaved coded-modulation (BICM) as a practical coding scheme for the
proposed strategy. We consider matched and mismatched scenarios, depending on
whether the input alphabet of the interference signal is known or unknown to
the decoder, respectively. For the matched scenario, we show the proposed
strategy results in significant gains in SNR. For the mismatched scenario, we
show that the proposed strategy results in rate improvements that, without the
relay, cannot be achieved by merely increasing transmit powers. Finally, we use
generalized mutual information analysis to characterize the theoretical
performance of the mismatched scenario and validate our simulation results.


  Chordal clutters in the sense of [14] and [3] are defined via simplicial
orders. Their circuit ideal has a linear resolution, independent of the
characteristic of the base field. We show that any Betti sequence of an ideal
with linear resolution appears as the Betti sequence of the circuit ideal of
such a chordal clutter. Associated with any simplicial order is a sequence of
integers which we call the $\lambda$-sequence of the chordal clutter. All
possible $\lambda$-sequences are characterized. They are intimately related to
the Hilbert function of a suitable standard graded $K$-algebra attached to the
chordal clutter. By the $\lambda$-sequence of a chordal clutter we determine
other numerical invariants of the circuit ideal, such as the
$\textbf{h}$-vector and the Betti numbers.


  We measure the masses of $b$ hadrons in exclusively reconstructed final
states containing a $J/\psi\to\mu^-\mu^+$ decay using $\rm 220 pb^{-1}$ of data
collected by the CDF II experiment. We find: m(B^+) = 5279.10 \pm
0.41_{(stat.)} \pm 0.36_{(sys.)} MeVcc, m(B^0) = 5279.63 \pm 0.53_{(stat.)} \pm
0.33_{(sys.)} MeVcc, m(B^0_s) = 5366.01 \pm 0.73_{(stat.)} \pm 0.33_{(sys.)}
MeVcc, m(\Lambda^0_b) = 5619.7 \pm 1.2_{(stat.)} \pm 1.2_{(sys.)} MeVcc. m(B^+)
- m(B^0) = -0.53 \pm 0.67_{(stat.)} \pm 0.14_{(sys.)} MeVcc, m(B^0_s) - m(B^0)
= 86.38 \pm 0.90_{(stat.)} \pm 0.06_{(sys.)} MeVcc m(\Lambda^0_b) - m(B^0) =
339.2 \pm 1.4_{(stat.)} \pm 0.1_{(sys.)} MeVcc. The measurements of the
$B^0_s$, $\Lambda^0_b$ mass, $m(B^0_s)-m(B^0)$ and $m(\Lambda^0_b)-m(B^0)$ mass
difference are of better precision than the current world averages.


  We review the W_N algebra and its quantum deformation, based on free field
realizations. The (quantum deformed) W_N algebra is defined through the
(quantum deformed) Miura transformation, and its singular vectors realize the
Jack (Macdonald) polynomials. (Talk at the Nankai-CRM joint meeting on
``Extended and Quantum Algebras and their Applications to Physics'', Tianjin,
China, August 19-24, 1996.)


  We consider problems of rating alternatives based on their pairwise
comparison under various assumptions, including constraints on the final scores
of alternatives. The problems are formulated in the framework of tropical
mathematics to approximate pairwise comparison matrices by reciprocal matrices
of unit rank, and written in a common form for both multiplicative and additive
comparison scales. To solve the unconstrained and constrained approximation
problems, we apply recent results in tropical optimization, which provide new
complete direct solutions given in a compact vector form. These solutions
extend known results and involve less computational effort. As an illustration,
numerical examples of rating alternatives are presented.


  Let $G$ be a finite primitive permutation group on a set $\Omega$ and recall
that the fixed point ratio of an element $x \in G$, denoted ${\rm fpr}(x)$, is
the proportion of points in $\Omega$ fixed by $x$. Fixed point ratios in this
setting have been studied for many decades, finding a wide range of
applications. In this paper, we are interested in comparing ${\rm fpr}(x)$ with
the order of $x$. Our main theorem classifies the triples $(G,\Omega,x)$ as
above with the property that $x$ has prime order $r$ and ${\rm fpr}(x) >
1/(r+1)$. There are several applications. Firstly, we extend earlier work of
Guralnick and Magaard by determining the primitive permutation groups of degree
$m$ with minimal degree at most $2m/3$. Secondly, our main result plays a key
role in recent work of the authors (together with Moret\'{o} and Navarro) on
the commuting probability of $p$-elements in finite groups. Finally, we use our
main theorem to investigate the minimal index of a primitive permutation group,
which allows us to answer a question of Bhargava.


  We consider multi-point correlation functions in the open XXZ chain with
longitudinal boundary fields and in a uniform external magnetic field. We show
that, at finite temperature, these correlation functions can be written in the
quantum transfer matrix framework as sums over thermal form factors. More
precisely, and quite remarkably, each term of the sum is given by a simple
product of usual matrix elements of the quantum transfer matrix multiplied by a
unique factor containing the whole information about the boundary fields. As an
example, we provide a detailed expression for the longitudinal spin one-point
functions at distance $m$ from the boundary. This work thus solves the
long-standing problem of setting up form factor expansions in integrable models
subject to open boundary conditions.


  Urban villages, defined as informal residential areas in or around urban
centers, are characterized by inadequate infrastructures and poor living
conditions, closely related to the Sustainable Development Goals (SDGs) on
poverty, adequate housing, and sustainable cities. Traditionally, governments
heavily depend on field survey methods to monitor the urban villages, which
however are time-consuming, labor-intensive, and possibly delayed. Thanks to
widely available and timely updated satellite images, recent studies develop
computer vision techniques to detect urban villages efficiently. However,
existing studies either focus on simple urban village image classification or
fail to provide accurate boundary information. To accurately identify urban
village boundaries from satellite images, we harness the power of the vision
foundation model and adapt the Segment Anything Model (SAM) to urban village
segmentation, named UV-SAM. Specifically, UV-SAM first leverages a small-sized
semantic segmentation model to produce mixed prompts for urban villages,
including mask, bounding box, and image representations, which are then fed
into SAM for fine-grained boundary identification. Extensive experimental
results on two datasets in China demonstrate that UV-SAM outperforms existing
baselines, and identification results over multiple years show that both the
number and area of urban villages are decreasing over time, providing deeper
insights into the development trends of urban villages and sheds light on the
vision foundation models for sustainable cities. The dataset and codes of this
study are available at https://github.com/tsinghua-fib-lab/UV-SAM.


  Background: We sought to determine if ripple oscillations (80-120Hz),
detected in intracranial EEG (iEEG) recordings of epilepsy patients, correlate
with an enhancement or disruption of verbal episodic memory encoding. Methods:
We defined ripple and spike events in depth iEEG recordings during list
learning in 107 patients with focal epilepsy. We used logistic regression
models (LRMs) to investigate the relationship between the occurrence of ripple
and spike events during word presentation and the odds of successful word
recall following a distractor epoch, and included the seizure onset zone (SOZ)
as a covariate in the LRMs. Results: We detected events during 58,312 word
presentation trials from 7,630 unique electrode sites. The probability of
ripple on spike (RonS) events was increased in the seizure onset zone (SOZ,
p<0.04). In the left temporal neocortex RonS events during word presentation
corresponded with a decrease in the odds ratio (OR) of successful recall,
however this effect only met significance in the SOZ (OR of word recall 0.71,
95% CI: 0.59-0.85, n=158 events, adaptive Hochberg p<0.01). Ripple on
oscillation events (RonO) that occurred in the left temporal neocortex non-SOZ
also correlated with decreased odds of successful recall (OR 0.52, 95% CI:
0.34-0.80, n=140, adaptive Hochberg , p<0.01). Spikes and RonS that occurred
during word presentation in the left middle temporal gyrus during word
presentation correlated with the most significant decrease in the odds of
successful recall, irrespective of the location of the SOZ (adaptive Hochberg,
p<0.01). Conclusion: Ripples and spikes generated in left temporal neocortex
are associated with impaired verbal episodic memory encoding.


  An ion beam cooler and buncher has been developed for the manipulation of
radioactive ion beams. The gas-filled linear radiofrequency ion trap system is
installed at the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. Its
purpose is to accumulate the 60-keV continuous ISOLDE ion beam with high
efficiency and to convert it into low-energy low-emittance ion pulses. The
efficiency was found to exceed 10% in agreement with simulations. A more than
10-fold reduction of the ISOLDE beam emittance can be achieved. The system has
been used successfully for first on-line experiments. Its principle, setup and
performance will be discussed.


  Let $A$ be a discrete valuation ring with field of fractions $F$ and
(sufficiently large) residue field $k$. We prove that there is a natural exact
sequence $H_3(\mathrm{SL}_2(A),\mathbb{Z}[\frac{1}{2}]) \to
H_3(\mathrm{SL}_2(F),\mathbb{Z}[\frac{1}{2}])\to
\mathcal{RP}_1(k)[\frac{1}{2}]\to 0$, where $\mathcal{RP}_1(k)$ is the refined
scissors congruence group of $k$. Let $\Gamma_0(\mathfrak{m}_A)$ denote the
congruence subgroup consisting of matrices in $\mathrm{SL}_2(A)$ whose lower
off-diagonal entry lies in the maximal ideal $\mathfrak{m}_A$. We also prove
that there is an exact sequence $0\to \overline{\mathcal{P}}(k)[\frac{1}{2}]\to
H_2(\Gamma_0(\mathfrak{m}_A),\mathbb{Z}[\frac{1}{2}])\to
H_2(\mathrm{SL}_2(A),\mathbb{Z}[\frac{1}{2}])\to I^2(k)[\frac{1}{2}]\to 0$,
where $I^2(k)$ is the second power of the fundamental ideal of the
Grothendieck-Witt ring $\mathrm{GW}(k)$ and $\overline{\mathcal{P}}(k)$ is a
certain quotient of the scissors congruence group (in the sense of Dupont-Sah)
$\mathcal{P}(k)$ of $k$.


  The minimum degree algorithm is one of the most widely-used heuristics for
reducing the cost of solving large sparse systems of linear equations. It has
been studied for nearly half a century and has a rich history of bridging
techniques from data structures, graph algorithms, and scientific computing. In
this paper, we present a simple but novel combinatorial algorithm for computing
an exact minimum degree elimination ordering in $O(nm)$ time, which improves on
the best known time complexity of $O(n^3)$ and offers practical improvements
for sparse systems with small values of $m$. Our approach leverages a careful
amortized analysis, which also allows us to derive output-sensitive bounds for
the running time of $O(\min\{m\sqrt{m^+}, \Delta m^+\} \log n)$, where $m^+$ is
the number of unique fill edges and original edges that the algorithm
encounters and $\Delta$ is the maximum degree of the input graph.
  Furthermore, we show there cannot exist an exact minimum degree algorithm
that runs in $O(nm^{1-\varepsilon})$ time, for any $\varepsilon > 0$, assuming
the strong exponential time hypothesis. This fine-grained reduction goes
through the orthogonal vectors problem and uses a new low-degree graph
construction called $U$-fillers, which act as pathological inputs and cause any
minimum degree algorithm to exhibit nearly worst-case performance. With these
two results, we nearly characterize the time complexity of computing an exact
minimum degree ordering.


  On 1 June 2019, just before 7:30 PM local time, the Desert Fireball Network
detected a -9.3 magnitude fireball over South Australia near the Western
Australia border. The event was observed by six fireball observatories, and
lasted for five seconds. One station was nearly directly underneath the
trajectory, greatly constraining the trajectory solution. This trajectory's
backward numerical integrations indicate that the object originated from the
outer main belt with a semi-major axis of 2.75 au. A light curve was also
extracted and showed that the body experienced very little fragmentation during
its atmospheric passage. A search campaign was conducted with several Desert
Fireball Network team members and other volunteers. One 42 g fragment was
recovered within the predicted fall area based on the dark flight model. Based
on measurements of short-lived radionuclides, the fragment was confirmed to be
a fresh fall. The meteorite, Arpu Kuilpu, has been classified as an H5 ordinary
chondrite. This marks the fifth fall recovered in Australia by the Desert
Fireball Network, and the smallest meteoroid ($\simeq 2$ kg) to ever survive
entry and be recovered as a meteorite.


  Notions of nonstabilizerness, or "magic", quantify how non-classical quantum
states are in a precise sense: states exhibiting low nonstabilizerness preclude
quantum advantage. We introduce 'pseudomagic' ensembles of quantum states that,
despite low nonstabilizerness, are computationally indistinguishable from those
with high nonstabilizerness. Previously, such computational
indistinguishability has been studied with respect to entanglement, introducing
the concept of pseudoentanglement. However, we demonstrate that pseudomagic
neither follows from pseudoentanglement nor implies it. In terms of
applications, the study of pseudomagic offers fresh insights into the theory of
quantum scrambling: it uncovers states that, even though they originate from
non-scrambling unitaries, remain indistinguishable from scrambled states to any
physical observer. Additional applications include new lower bounds on state
synthesis problems, property testing protocols, and implications for quantum
cryptography. Our work is driven by the observation that only quantities
measurable by a computationally bounded observer - intrinsically limited by
finite-time computational constraints - hold physical significance. Ultimately,
our findings suggest that nonstabilizerness is a 'hide-able' characteristic of
quantum states: some states are much more magical than is apparent to a
computationally bounded observer.


  Over the past several years, the Hubble Space Telescope (HST) has acquired
many broad-band images of various regions in the M31 disk. I have obtained 27
such fields from the HST data archive in order to produce color-magnitude
diagrams (CMDs) of the stellar populations contained within these areas of the
disk. I have attempted to reproduce these CMDs using theoretical stellar
evolution models in conjunction with statistical tools for determining the star
formation history which best fits the observations. The wide range of
extinction values within any given field makes the data difficult to accurately
reproduce; nevertheless, I have managed to find star formation histories which
roughly reproduce the data. These statistically determined star formation
histories reveal that, like the disk of the Galaxy, the disk of M31 contains
very few old metal-poor stars. The histories also suggest that the star
formation rate of the disk as a whole has been low over the past ~1 Gyr.


  Among many unsolved puzzles in theories of Deep Neural Networks (DNNs), there
are three most fundamental challenges that highly demand solutions, namely,
expressibility, optimisability, and generalisability. Although there have been
significant progresses in seeking answers using various theories, e.g.
information bottleneck theory, sparse representation, statistical inference,
Riemannian geometry, etc., so far there is no single theory that is able to
provide solutions to all these challenges. In this work, we propose to engage
the theory of differential topology to address the three problems. By modelling
the dataset of interest as a smooth manifold, DNNs can be considered as
compositions of smooth maps between smooth manifolds. Specifically, our work
offers a differential topological view of loss landscape of DNNs, interplay
between width and depth in expressibility, and regularisations for
generalisability. Finally, in the setting of deep representation learning, we
further apply the quotient topology to investigate the architecture of DNNs,
which enables to capture nuisance factors in data with respect to a specific
learning task.


  Pulse-coupled systems such as spiking neural networks exhibit nontrivial
invariant sets in the form of attracting yet unstable saddle periodic orbits
where units are synchronized into groups. Heteroclinic connections between such
orbits may in principle support switching processes in those networks and
enable novel kinds of neural computations. For small networks of coupled
oscillators we here investigate under which conditions and how system symmetry
enforces or forbids certain switching transitions that may be induced by
perturbations. For networks of five oscillators we derive explicit transition
rules that for two cluster symmetries deviate from those known from oscillators
coupled continuously in time. A third symmetry yields heteroclinic networks
that consist of sets of all unstable attractors with that symmetry and the
connections between them. Our results indicate that pulse-coupled systems can
reliably generate well-defined sets of complex spatiotemporal patterns that
conform to specific transition rules. We briefly discuss possible implications
for computation with spiking neural systems.


  We present an explicit version of Berger, Coburn and Lebow's classification
result for pure pairs of commuting isometries in the sense of an explicit
recipe for constructing pairs of commuting isometric multipliers with precise
coefficients. We describe a complete set of (joint) unitary invariants and
compare the Berger, Coburn and Lebow's representations with other natural
analytic representations of pure pairs of commuting isometries. Finally, we
study the defect operators of pairs of commuting isometries.


  We incorporate hydrodynamic interactions (HI) in a coarse-grained and
structure-based model of proteins by employing the Rotne-Prager hydrodynamic
tensor. We study several small proteins and demonstrate that HI facilitate
folding. We also study HIV-1 protease and show that HI make the flap closing
dynamics faster. The HI are found to affect time correlation functions in the
vicinity of the native state even though they have no impact on same time
characteristics of the structure fluctuations around the native state.


  In this presentation, we briefly review recent investigations on pion and
kaon structures from the instanton vacuum. Starting from the low-energy QCD
partition function, we have computed the Gasser-Leutwyler low-energy constants,
electromagnetic form factors of the pion and kaon, semileptonic decay form
factors of the kaon, and light-cone distribution amplitues of the pion and
kaon. The results are in good agreement with the experimental and empirical
data.


  The existing volumetric gain for robotic exploration is calculated in the 3D
occupancy map, while the sampling-based exploration method is extended in the
reachable (free) space. The inconsistency between them makes the existing
calculation of volumetric gain inappropriate for a complete exploration of the
environment. To address this issue, we propose a concave-hull based volumetric
gain in a sampling-based exploration framework. The concave hull is constructed
based on the viewpoints generated by Rapidly-exploring Random Tree (RRT) and
the nodes that fail to expand. All space outside this concave hull is
considered unknown. The volumetric gain is calculated based on the viewpoints
configuration rather than using the occupancy map. With the new volumetric
gain, robots can avoid inefficient or even erroneous exploration behavior
caused by the inappropriateness of existing volumetric gain calculation
methods. Our exploration method is evaluated against the existing
state-of-the-art RRT-based method in a benchmark environment. In the evaluated
environment, the average running time of our method is about 38.4% of the
existing state-of-the-art method and our method is more robust.


  We prove that if g and n are integers at least two, then the abstract
commensurator of the braid group with n strands on a closed orientable surface
of genus g is naturally isomorphic to the extended mapping class group of a
compact orientable surface of genus g with n boundary components.


  We study frequency domain electromagnetic scattering at a bounded,
penetrable, and inhomogeneous obstacle $ \Omega \subset \mathbb{R}^3 $. From
the Stratton-Chu integral representation, we derive a new representation
formula when constant reference coefficients are given for the interior domain.
The resulting integral representation contains the usual layer potentials, but
also volume potentials on $\Omega$. Then it is possible to follow a
single-trace approach to obtain boundary integral equations perturbed by traces
of compact volume integral operators with weakly singular kernels. The coupled
boundary and volume integral equations are discretized with a Galerkin approach
with usual Curl-conforming and Div-conforming finite elements on the boundary
and in the volume. Compression techniques and special quadrature rules for
singular integrands are required for an efficient and accurate method.
Numerical experiments provide evidence that our new formulation enjoys
promising properties.


  Some aspects of the systematic and statistical errors affecting grid-based
estimation of stellar masses and radii have still not been investigated well.
We study the impact on mass and radius determination of the uncertainty in the
input physics, in the mixing-length value, in the initial helium abundance, and
in the microscopic diffusion efficiency adopted in stellar model computations.
We consider stars with mass in the range [0.8 - 1.1] Msun and evolutionary
stages from the zero-age main sequence to the central hydrogen exhaustion.
Stellar parameters were recovered by a maximum-likelihood technique, comparing
the observations constraints to a grid of stellar models. Synthetic grids with
perturbed input were adopted to estimate the systematic errors arising from the
current uncertainty in model computations. We found that the statistical error
components, owing to the current typical uncertainty in the observations, are
nearly constant in all cases at about 4.5% and 2.2% on mass and radius
determination, respectively. The systematic bias on mass and radius
determination due to a variation of $\pm$ 1 in Delta Y/Delta Z is $\pm$ 2.3%
and $\pm$ 1.1%; the one due to a change of $\pm$ 0.24 in the value of the
mixing-length is $\pm$ 2.1% and $\pm$ 1.0%; the one due to a variation of $\pm$
5% in the radiative opacity is $\mp$ 1.0% and $\mp$ 0.45%. An important bias
source is to neglect microscopic diffusion, which accounts for errors of about
3.7% and 1.5% on mass and radius. The cumulative effects of the considered
uncertainty sources can produce biased estimates of stellar characteristics.
Comparison of the results of our technique with other grid techniques shows
that the systematic biases induced by the differences in the estimation grids
are generally greater than the statistical errors involved.


  Balayage of measures with respect to classes of all subharmonic or harmonic
functions on an open set of a plane or finite-dimensional Euclidean space is
one of the main objects of potential theory and its applications to the complex
analysis. For a class $H$ of functions on $O$, a measure $\omega$ on $O$ is a
balayage of a measure $\delta$ on $O$ with respect to this class $H$ if $\int_O
h\, d \delta\leq \int_O h\, d\omega$ for each $h\in H$. In our previous works
we used this concept to study envelopes relative to classes of subharmonic and
harmonic functions and apply them to describe zero sets of holomorphic
functions on $O$ with growth restrictions near the boundary of $O$. In this
article, we consider the complex plane $\mathbb C$ as $O$, and instead of the
classes of all (sub)harmonic functions on $\mathbb C$, we use only the classes
of harmonic polynomials of degree at most $p$, often together with the
logarithmic functions-kernels $z\mapsto \ln |w-z|$, $w\in \mathbb C$. Our
research has show that this case has both many similarities and features
compared to previous situations. The following issues are considered: the
sensitivity of balayage of measures to polar sets; the duality between balayage
of measures and their logarithmic potentials, together with a complete internal
description of such potentials; extension/prolongation of balayage with respect
to polynomials and logarithmic kernels to balayage with respect to subharmonic
functions of finite order $p$. The planned applications of these results to the
theory of entire and meromorphic functions of finite order are not discussed
here and will be presented later.


  After the discovery of Dirac fermions in graphene, it has become a natural
question to ask whether it is possible to realize Dirac fermions in other
two-dimensional (2D) materials as well. In this work, we report the discovery
of multiple Dirac-like electronic bands in ultrathin Ge films grown on Au(111)
by angle-resolved photoelectron spectroscopy. By tuning the thickness of the
films, we are able to observe the evolution of their electronic structure when
passing through the monolayer limit. Our discovery may signify the synthesis of
germanene, a 2D honeycomb structure made of Ge, which is a promising platform
for exploring exotic topological phenomena and enabling potential applications.


  A critical step in the bacteriophage life cycle is genome ejection into host
bacteria. The ejection process for double-stranded DNA phages has been studied
thoroughly \textit{in vitro}, where after triggering with the cellular receptor
the genome ejects into a buffer. The experimental data have been interpreted in
terms of the decrease in free energy of the densely packed DNA associated with
genome ejection. Here we detail a simple model of genome ejection in terms of
the hydrostatic and osmotic pressures inside the phage, a bacterium, and a
buffer solution/culture medium. We argue that the hydrodynamic flow associated
with the water movement from the buffer solution into the phage capsid and
further drainage into the bacterial cytoplasm, driven by the osmotic gradient
between the bacterial cytoplasm and culture medium, provides an alternative
mechanism for phage genome ejection \textit{in vivo}; the mechanism is
perfectly consistent with phage genome ejection \textit{in vitro}.


  We show that the Extrinsic Information about the coded bits of any good
(capacity achieving) code operating over a wide class of discrete memoryless
channels (DMC) is zero when channel capacity is below the code rate and
positive constant otherwise, that is, the Extrinsic Information Transfer (EXIT)
chart is a step function of channel quality, for any capacity achieving code.
It follows that, for a common class of iterative receivers where the error
correcting decoder must operate at first iteration at rate above capacity (such
as in turbo equalization, turbo channel estimation, parallel and serial
concatenated coding and the like), classical good codes which achieve capacity
over the DMC are not effective and should be replaced by different new ones.
Another meaning of the results is that a good code operating at rate above
channel capacity falls apart into its individual transmitted symbols in the
sense that all the information about a coded transmitted symbol is contained in
the corresponding received symbol and no information about it can be inferred
from the other received symbols. The binary input additive white Gaussian noise
channel is treated in part 1 of this report. Part 2 extends the results to the
symmetric binary channel and to the binary erasure channel and provides an
heuristic extension to wider class of channel models.


  "Magic" is the degree to which a state cannot be approximated by Clifford
gates. We study mana, a measure of magic, in the ground state of the $\mathbb
Z_3$ Potts model, and argue that it is a broadly useful diagnostic for
many-body physics. In particular we find that the $q = 3$ ground state has
large mana at the model's critical point, and that this mana resides in the
system's correlations. We explain the form of the mana by a simple
tensor-counting calculation based on a MERA representation of the state.
Because mana is present at all length scales, we conclude that the conformal
field theory describing the 3-state Potts model critical point is magical.
These results control the difficulty of preparing the Potts ground state on an
error-corrected quantum computer, and constrain tensor network models of
AdS-CFT.


  The first X-ray afterglow for a short (~30 ms), hard gamma-ray burst was
detected by Swift on 9 May 2005 (GRB 050509b). No optical or radio counterpart
was identified in follow-up observations. The tentative association of the GRB
with a nearby giant elliptical galaxy at redshift z=0.2248 would imply a total
energy release E(gamma, isotropic) ~3 x 10**48 erg, and that the progenitor had
traveled several tens of kpc from its point of origin, in agreement with
expectations linking these events to the final merger of compact binaries
driven by gravitational wave emission. We model the dynamical merger of such a
system and the time-dependent evolution of the accretion tori thus created. The
resulting energetics, variability, and expected durations are consistent with
GRB 050509b originating from the tidal disruption of a neutron star by a
stellar mass black hole, or of the merger of two neutron stars followed by
prompt gravitational collapse of the massive remnant. We discuss how the
available gamma-ray and X-ray data provide a probe for the nature of the
relativistic ejecta and the surrounding medium.


  We derive expansions of the resolvent
Rn(x;y;t)=(Qn(x;t)Pn(y;t)-Qn(y;t)Pn(x;t))/(x-y) of the Hermite kernel Kn at the
edge of the spectrum of the finite n Gaussian Unitary Ensemble (GUEn) and the
finite n expansion of Qn(x;t) and Pn(x;t). Using these large n expansions, we
give another proof of the derivation of an Edgeworth type theorem for the
largest eigenvalue distribution function of GUEn. We conclude with a brief
discussion on the derivation of the probability distribution function of the
corresponding largest eigenvalue in the Gaussian Orthogonal Ensemble (GOEn) and
Gaussian Symplectic Ensembles (GSEn).


  The Parareal algorithm allows to solve evolution problems exploiting
parallelization in time. Its convergence and stability have been proved under
the assumption of regular (smooth) inputs. We present and analyze here a new
Parareal algorithm for ordinary differential equations which involve
discontinuous right-hand sides. Such situations occur in various applications,
e.g., when an electric device is supplied with a pulse-width-modulated signal.
Our new Parareal algorithm uses a smooth input for the coarse problem with
reduced dynamics. We derive error estimates that show how the input reduction
influences the overall convergence rate of the algorithm. We support our
theoretical results by numerical experiments, and also test our new Parareal
algorithm in an eddy current simulation of an induction machine.


  Quasar outflows might either quench (negative) or enhance (positive feedback)
star formation in galaxies located in the quasar environment. The possible
outcome depends on 4 parameters: the quasar ($\sigma$) and satellite
($\sigma_*$) halo velocity dispersion, their relative distance, $d$, and
satellite disk radius, $r_d$. We find that: (i) small satellites with $\sigma
_* < 164\ \sigma_{200}^{2/3}\, \rm km\ s^{-1}$ have their star formation
quenched; (ii) in larger satellites, star formation, and hence UV/FIR
luminosity, is instead boosted by $>80$\% in a burst with a typical duration of
$5-10$ Myr, if the following positive feedback criterion is met: ${d}/{r_d} <
15 (Q/\eta)^{1/2} \sigma_{200}$, where $Q \approx 1$ is the satellite disk
Toomre parameter; the disruption parameter (see eq. 17) must be $\eta>1$ to
prevent complete satellite gas removal. We compare our predictions with ALMA
data finding that observed satellites of $z\simeq 6$ QSOs on average form stars
at a $3\times$ higher rate with respect to field galaxies at the same redshift.
Further tests of the model are suggested.


  Three long standing problems related to the physics of water viz, the
possibility of vitrifying bulk water by rapid quenching, its glass transition,
and the supposed impossibility of obtaining supercooled water between 150 and
233 K, the so-called 'no man's land'of its phase diagram, are studied using the
highly sensitive technique of spin probe ESR. Our results suggest that water
can indeed be vitrified by rapid quenching, it undergoes a glass transition at
\~ 135 K, and the relaxation behavior studied using this method between 165 K
and 233 K closely follows the predictions of the Adam-Gibbs model.


  In this paper, we focus on the demodulation/decoding of the complex
modulations/codes that approach the Shannon capacity. Theoretically, the
maximum likelihood (ML) algorithm can achieve the optimal error performance
whereas it has $\mathcal{O}(2^k)$ demodulation/decoding complexity with $k$
denoting the number of information bits. Recent progress in deep learning
provides a new direction to tackle the demodulation and the decoding. The
purpose of this paper is to analyze the feasibility of the neural network to
demodulate/decode the complex modulations/codes close to the Shannon capacity
and characterize the error performance and the complexity of the neural
network. Regarding the neural network demodulator, we use the golden angle
modulation (GAM), a promising modulation format that can offer the Shannon
capacity approaching performance, to evaluate the demodulator. It is observed
that the neural network demodulator can get a close performance to the ML-based
method while it suffers from the lower complexity order in the low-order GAM.
Regarding the neural network decoder, we use the Gaussian codebook, achieving
the Shannon capacity, to evaluate the decoder. We also observe that the neural
network decoder achieves the error performance close to the ML decoder with a
much lower complexity order in the small Gaussian codebook. Limited by the
current training resources, we cannot evaluate the performance of the
high-order modulation and the long codeword. But, based on the results of the
low-order GAM and the small Gaussian codebook, we boldly give our conjecture:
the neural network demodulator/decoder is a strong candidate approach for
demodulating/decoding the complex modulations/codes close to the Shannon
capacity owing to the error performance of the near-ML algorithm and the lower
complexity.


  We present a formulation of naturalness made in the framework of Bayesian
statistics, which unravels the conceptual problems related to previous
approaches. Among other things, the relative interpretation of the measure of
naturalness turns out to be unambiguously established by Jeffreys' scale. Also,
the usual sensitivity formulation (so-called Barbieri-Giudice measure) appears
to be embedded in our formulation under an extended form. We derive the general
sensitivity formula applicable to an arbitrary number of observables. Several
consequences and developments are further discussed. As a final illustration,
we work out the map of combined fine-tuning associated to the gauge hierarchy
problem and neutralino dark matter in a classic supersymmetric model.


  Among the many interesting features displayed by graphene, one of the most
attractive is the simplicity with which its electronic structure can be
described. The study of its physical properties is significantly simplified by
the linear dispersion relation of electrons in a narrow range around the Fermi
level. Unfortunately, the mathematical simplicity of graphene electrons is only
limited to this narrow energy region and is useless when dealing with problems
that involve energies outside the linear dispersion part of the spectrum. In
this letter we remedy this limitation by deriving a set of closed-form
analytical expressions for the real-space single-electron Green function of
graphene which are valid across an enormous fraction of the energy spectrum. By
extending to a wider energy range the simplicity with which graphene electrons
are described, it is now possible to derive more mathematically transparent and
insightful expressions for a number of physical properties that involve higher
energy scales. The power of this new formalism is illustrated in the case of
the magnetic (RKKY) interaction in graphene.


  We present the first detailed thermal and velocity field characterization of
convection in a rotating cylindrical tank of liquid gallium, which has
thermophysical properties similar to those of planetary core fluids. Our
laboratory experiments, and a closely associated direct numerical simulation,
are all carried out in the regime prior to the onset of steady convective
modes. This allows us to study the oscillatory convective modes, sidewall modes
and broadband turbulent flow that develop in liquid metals before the advent of
steady columnar modes. Our thermo-velocimetric measurements show that strongly
inertial, thermal wind flows develop, with velocities reaching those of
comparable non-rotating cases. Oscillatory bulk convection and wall modes
coexist across a wide range of our experiments, along with strong zonal flows
that peak in the Stewartson layer, but that extend deep into the fluid bulk in
the higher supercriticality cases. The flows contain significant time-mean
helicity that is anti-symmetric across the midplane, demonstrating that
oscillatory liquid metal convection contains the kinematic components to
sustain system-scale dynamo generation.


  Multi-modal densities appear frequently in time series and practical
applications. However, they cannot be represented by common state estimators,
such as the Extended Kalman Filter (EKF) and the Unscented Kalman Filter (UKF),
which additionally suffer from the fact that uncertainty is often not captured
sufficiently well, which can result in incoherent and divergent tracking
performance. In this paper, we address these issues by devising a non-linear
filtering algorithm where densities are represented by Gaussian mixture models,
whose parameters are estimated in closed form. The resulting method exhibits a
superior performance on typical benchmarks.


  We apply negative dimensional integration method (NDIM) to three outstanding
gauges: Feynman, light-cone and Coulomb gauges. Our aim is to show that NDIM is
a very suitable technique to deal with loop integrals, being them originated
from any gauge choice. In Feynman gauge we perform scalar two-loop four-point
massless integrals; in the light-cone gauge we calculate scalar two-loop
integrals contributing for two-point functions without any kind of
prescriptions, since NDIM can abandon such devices -- this calculation is the
first test of our prescriptionless method beyond one-loop order; finally, for
the Coulomb gauge we consider a four propagator massless loop integral, in the
split dimensional regularization context.


  Mirroring the complex structures and diverse functions of natural organisms
is a long-standing challenge in robotics. Modern fabrication techniques have
dramatically expanded feasible hardware, yet deploying these systems requires
control software to translate desired motions into actuator commands. While
conventional robots can easily be modeled as rigid links connected via joints,
it remains an open challenge to model and control bio-inspired robots that are
often multi-material or soft, lack sensing capabilities, and may change their
material properties with use. Here, we introduce Neural Jacobian Fields, an
architecture that autonomously learns to model and control robots from vision
alone. Our approach makes no assumptions about the robot's materials,
actuation, or sensing, requires only a single camera for control, and learns to
control the robot without expert intervention by observing the execution of
random commands. We demonstrate our method on a diverse set of robot
manipulators, varying in actuation, materials, fabrication, and cost. Our
approach achieves accurate closed-loop control and recovers the causal dynamic
structure of each robot. By enabling robot control with a generic camera as the
only sensor, we anticipate our work will dramatically broaden the design space
of robotic systems and serve as a starting point for lowering the barrier to
robotic automation.


  We report the development and benchmark of multireference algebraic
diagrammatic construction theory (MR-ADC) for the simulations of core-excited
states and X-ray absorption spectra (XAS). Our work features an implementation
that incorporates core-valence separation into the strict and extended
second-order MR-ADC approximations (MR-ADC(2) and MR-ADC(2)-X), providing an
efficient access to high-energy excited states without including inner-shell
orbitals in the active space. Benchmark results on a set of small molecules
indicate that at equilibrium geometries the accuracy of MR-ADC is similar to
that of single-reference ADC theory when static correlation effects are not
important. In this case, MR-ADC(2)-X performs similarly to single- and
multireference coupled cluster methods in reproducing the experimental XAS peak
spacings. We demonstrate the potential of MR-ADC for chemical systems with
multiconfigurational electronic structure by calculating the K-edge XAS
spectrum of the ozone molecule with a multireference character in its ground
electronic state and the dissociation curve of core-excited molecular nitrogen.
For ozone, the MR-ADC results agree well with the data from experimental and
previous multireference studies of ozone XAS, in contrast to the results of
single-reference methods, which underestimate relative peak energies and
intensities. The MR-ADC methods also predict the correct shape of core-excited
nitrogen potential energy curve, in a good agreement with accurate calculations
using driven similarity renormalization group approaches. These findings
suggest that MR-ADC(2) and MR-ADC(2)-X are promising methods for the XAS
simulations of multireference systems and pave the way for their efficient
computer implementation and applications.


  A comprehensive analysis of general relativistic spacetimes which admit a
shear-free, irrotational and geodesic timelike congruence is presented. The
equations governing the models for a general energy-momentum tensor are written
down. Coordinates in which the metric of such spacetimes takes on a simplified
form are established. The general subcases of `zero anisotropic stress', `zero
heat flux vector' and `two component fluids' are investigated. In particular,
perfect fluid Friedmann-Robertson-Walker models and spatially homogeneous
models are discussed. Models with a variety of physically relevant
energy-momentum tensors are considered. Anisotropic fluid models and viscous
fluid models with heat conduction are examined. Also, models with a perfect
fluid plus a magnetic field or with pure radiation, and models with two
non-collinear perfect fluids (satisfying a variety of physical conditions) are
investigated. In particular, models with a (single) perfect fluid which is
tilting with respect to the shear-free, vorticity-free and acceleration-free
timelike congruence are discussed.


  Recently, the old notion of causal boundary for a spacetime V has been
redefined in a consistent way. The computation of this boundary $\partial V$
for a standard conformally stationary spacetime V = R x M, suggests a natural
compactification $M_B$ associated to any Riemannian metric on M or, more
generally, to any Finslerian one. The corresponding boundary $\partial_B M$ is
constructed in terms of Busemann-type functions. Roughly, $\partial_B M$
represents the set of all the directions in M including both, asymptotic and
"finite" (or "incomplete") directions. This Busemann boundary $\partial_B M$ is
related to two classical boundaries: the Cauchy boundary and the Gromov
boundary. Our aims are: (1) to study the subtleties of both, the Cauchy
boundary for any generalized (possibly non-symmetric) distance and the Gromov
compactification for any (possibly incomplete) Finsler manifold, (2) to
introduce the new Busemann compactification $M_B$, relating it with the
previous two completions, and (3) to give a full description of the causal
boundary $\partial V$ of any standard conformally stationary spacetime.


  Generalized approximate message passing (GAMP) is a computationally efficient
algorithm for estimating an unknown signal $w_0\in\mathbb{R}^N$ from a random
linear measurement $y= Xw_0 + \epsilon\in\mathbb{R}^M$, where
$X\in\mathbb{R}^{M\times N}$ is a known measurement matrix and $\epsilon$ is
the noise vector. The salient feature of GAMP is that it can provide an
unbiased estimator $\hat{r}^{\rm G}\sim\mathcal{N}(w_0, \hat{s}^2I_N)$, which
can be used for various hypothesis-testing methods. In this study, we consider
the bootstrap average of an unbiased estimator of GAMP for the elastic net. By
numerically analyzing the state evolution of \emph{approximate message passing
with resampling}, which has been proposed for computing bootstrap statistics of
the elastic net estimator, we investigate when the bootstrap averaging reduces
the variance of the unbiased estimator and the effect of optimizing the size of
each bootstrap sample and hyperparameter of the elastic net regularization in
the asymptotic setting $M, N\to\infty, M/N\to\alpha\in(0,\infty)$. The results
indicate that bootstrap averaging effectively reduces the variance of the
unbiased estimator when the actual data generation process is inconsistent with
the sparsity assumption of the regularization and the sample size is small.
Furthermore, we find that when $w_0$ is less sparse, and the data size is
small, the system undergoes a phase transition. The phase transition indicates
the existence of the region where the ensemble average of unbiased estimators
of GAMP for the elastic net norm minimization problem yields the unbiased
estimator with the minimum variance.


  GAW, acronym for Gamma Air Watch, is a path-finder experiment to test the
feasibility of a new generation of imaging atmospheric Cherenkov telescopes
that join high flux sensitivity with large field of view capability. GAW is
conceived as an array of three identical imaging telescopes disposed at the
vertexes of an equilateral triangle, about 80 m side. Two main features
characterize GAW with respect to all the existing and presently planned
ground-based Cherenkov telescopes. The first difference concerns the optics
system: GAW uses a Fresnel refractive lens (2.13 m diameter) as light collector
instead of classical reflective mirror. The second main difference is the
detection working mode used: the detector at the focal surface operates in
single photoelectron counting mode instead of the usual charge integration one.
The GAW array is planned to be located at the Calar Alto Observatory site,
Spain, 2150 m a.s.l. During its first phase, only 6x6 degrees of the focal
plane detector will be implemented; moving it along the field of view, the
sensitivity of the telescopes will be tested observing the Crab Nebula with
on-axis and off-axis pointing up to 20 deg and with energy threshold of 300 GeV
and energy peak of 700 GeV. As path-finder, GAW will also monitor the Very High
Energy activity of some flaring Blazars as well as will follow-up GLAST
detections at high energies. In a second phase, the focal plane will be
enlarged to cover a field of view of 24 deg (full); pointing along different
North-South directions, GAW would reach a survey of 360x60 degrees region of
the sky. GAW is a collaboration effort of Research Institutes in Italy,
Portugal and Spain.


  We investigate two algebra of curves on a topological surface with punctures
- the cluster algebra of surfaces defined by Fomin, Shapiro, and Thurston, and
the generalized skein algebra constructed by Roger and Yang. By establishing
their compatibility, we resolve Roger-Yang's conjecture on the deformation
quantization of the decorated Teichmuller space. We also obtain several
structural results on the cluster algebra of surfaces. The cluster algebra of a
positive genus surface is not finitely generated, and it differs from its upper
cluster algebra.


  A new presentation of general solution of Navier-Stokes equations is
considered here. We consider equations of motion for 3-dimensional
non-stationary incompressible flow. The field of flow velocity as well as the
equation of momentum should be split to the sum of two components: an
irrotational (curl-free) one, and a solenoidal (divergence-free) one. The
obviously irrotational (curl-free) part of equation of momentum used for
obtaining of the components of pressure gradient. As a term of such an
equation, we used the irrotational (curl-free) vector field of flow velocity,
which is given by the proper potential (besides, the continuity equation
determines such a potential as a harmonic function). The other part of equation
of momentum could also be split to the sum of 2 equations: - with zero curl for
the field of flow velocity (viscous-free), and the proper Eq. with viscous
effects but variable curl. A solenoidal Eq. with viscous effects is represented
by the proper Heat equation for each component of flow velocity with variable
curl. Non-viscous case is presented by the PDE-system of 3 linear differential
equations (in regard to the time-parameter), depending on the components of
solution of the above Heat Eq. for the components of flow velocity with
variable curl. So, the existence of the general solution of Navier-Stokes
equations is proved to be the question of existence of the proper solution for
such a PDE-system of linear equations. Final solution is proved to be the sum
of 2 components: - an irrotational (curl-free) one and a solenoidal (variable
curl) components.


  The process of soliton Cherenkov radiation (also known as dispersive wave
emission) in microresonator frequency combs plays a critical role in generating
broadband and coherent microcomb spectra. Here, we report the observation of
symmetry breaking in the group velocity of counter-propagating dissipative Kerr
solitons, induced by polychromatic soliton Cherenkov radiation. Results show
that in the presence of higher-order dispersion, the temporal arrangement of a
multi-soliton state affects its group velocity, an effect which originates from
the interference between multiple radiative tails emitted by individual
solitons. Experimentally, we bidirectionally pump a microresonator with laser
fields of equal power and frequency, and observe lifting of the degeneracy
between the repetition rates of the counter-propagating solitons. The
observation of symmetry breaking despite symmetric pumping conditions not only
shines new light on the impact of dispersive waves on dissipative Kerr soliton
dynamics, but also introduces a novel approach to develop coherent dual-comb
spectrometers based on microcombs.


  Anti-counterfeiting technologies are indeed crucial for information security
and protecting product authenticity. Traditional anti-counterfeiting methods
have their limitations due to their clonable nature. Exploring new
technologies, particularly those based on pixel-level textures is a promising
avenue to address the clonable issue due to high encoding capacity. However,
research in this field is still in its infancy. This work introduces a new
fluorescent anti-counterfeiting label technology with four key characteristics:
efficient laser etching, high-throughput fabrication and segmentation,
robustness aided by data augmentation, and an exceptionally high recognition
speed. To be specific, the etching achieves a speed of 1,200 labels/3s, the
high throughput yields a rate of 2,400 labels/4 min, and a total count of
51,966 labels. The number of labels is further augmented to 5,196,600 by
implementing arbitrary rotation and brightness variation to enhance the
robustness in the recognition procedure. We divide these labels into 44
categories based on differences in patterns. Utilizing machine learning
methods, we have achieved a total recognition (including extraction and search
process) time per label averaging 421.96 ms without classification, and 40.13
ms with classification. Specifically, the search process with classification is
nearly fiftieth times shorter than the non-classification method, reaching 8.52
milliseconds in average. The overall recognition time is much faster than
previous works, and achieve an accuracy over 98.7%. This work significantly
increases the practicality of pixel-level anti-counterfeiting labels.


  We develop the notion of Rokhlin dimension for partial actions of finite
groups, extending the well-established theory for global systems. The partial
setting exhibits phenomena that cannot be expected for global actions, usually
stemming from the fact that virtually all averaging arguments for finite group
actions completely break down for partial systems. For example, fixed point
algebra and crossed product are not in general Morita equivalent, and there is
in general no local approximation of the crossed product $A\rtimes G$ by
matrices over $A$. By using decomposition arguments for partial actions of
finite groups, we show that a number of structural properties are preserved by
formation of crossed products, including finite stable rank, finite nuclear
dimension, and absorption of a strongly self-absorbing $C^*$-algebra. For
partial actions with the Rokhlin property, being an AF-algebra is also
preserved. Some of our results are new even in the global case.
  We also study the Rokhlin dimension of globalizable actions: while in general
it differs from the Rokhlin dimension of its globalization, we show that they
agree if the coefficient algebra is unital. For topological partial actions on
spaces of finite covering dimension, we show that finiteness of the Rokhlin
dimension is equivalent to freeness, thus providing a large class of examples
to which our theory applies.


  We propose Textiverse, a big data approach for mining geotagged timestamped
textual data on a map, such as for Twitter feeds, crime reports, or restaurant
reviews. We use a scalable data management pipeline that extracts keyphrases
from online databases in parallel. We speed up this time-consuming step so that
it outpaces the content creation rate of popular social media. The result is
presented in a web-based interface that integrates with Google Maps to
visualize textual content of massive scale. The visual design is based on
aggregating spatial regions into discrete sites and rendering each such site as
a circular tag cloud. To demonstrate the intended use of our technique, we
first show how it can be used to characterize the U.S.\ National Science
Foundation funding status based on all 489,151 awards. We then apply the same
technique on visually representing a more spatially scattered and
linguistically informal dataset: 1.2 million Twitter posts about the Android
mobile operating system.


  This paper generalizes the Stefan-Boltzmann law to include massive photons. A
crucial ingredient to obtain the correct formula for the radiance is to realize
that a massive photon does not travel at the speed of (massless) light. It
follows that, contrary to what could be expected, the radiance is not
proportional to the energy density times the speed of light.


  In recent years, lattice determinations of non-perturbative quantities such
as $f_K$ and $f_\pi$, which are relevant for $V_{us}$ and $V_{ud}$, have
reached an impressive precision of $\mathcal{O}(1\%)$ or better. To make
further progress, electromagnetic and strong isospin breaking effects must be
included in lattice QCD simulations.
  We present the status of the RBC/UKQCD lattice calculation of
isospin-breaking corrections to light meson leptonic decays. This computation
is performed in a (2+1)-flavor QCD simulation using Domain Wall Fermions with
near-physical quark masses. The isospin-breaking effects are implemented via a
perturbative expansion of the action in $\alpha$ and $(m_u-m_d)$. In this
calculation, we work in the electro-quenched approximation and the photons are
implemented in the Feynman gauge and $\text{QED}_\text{L}$ formulation.


  Gauge theories on graphs and networks are attracting increasing attention not
only as approaches to quantum gravity but also as models for performing quantum
computation. Here we propose a Dirac gauge theory for topological spinors in
$3+1$ dimensional networks associated to an arbitrary metric. Topological
spinors are the direct sum of $0$-cochains and $1$-cochains defined on a
network and describe a matter field defined on both nodes and links of a
network. Recently in Ref. \cite{bianconi2021topological} it has been shown that
topological spinors obey the topological Dirac equation driven by the discrete
Dirac operator. In this work we extend these results by formulating the Dirac
equation on weighted and directed $3+1$ dimensional networks which allow for
the treatment of a local theory. The commutators and anti-commutators of the
Dirac operators are non vanishing an they define the curvature tensor and
magnetic field of our theory respectively. This interpretation is confirmed by
the non-relativistic limit of the proposed Dirac equation. In the
non-relativistic limit of the proposed Dirac equation the sector of the spinor
defined on links follows the Schr\"odinger equation with the correct
giromagnetic moment, while the sector of the spinor defined on nodes follows
the Klein-Gordon equation and is not negligible. The action associated to the
proposed field theory comprises of a Dirac action and a metric action. We
describe the gauge invariance of the action under both Abelian and non-Abelian
transformations and we propose the equation of motion of the field theory of
both Dirac and metric fields. This theory can be interpreted as a limiting case
of a more general gauge theory valid on any arbitrary network in the limit of
almost flat spaces.


  Scenario of formation of fast radio bursts (FRBs) is proposed. Just like
radio pulsars, sources of FRBs are magnetized neutron stars. Appearance of
strong electric field in a magnetosphere of a neutron star is associated with
close passage of a dense body near hot neutron star. For the repeating source
FRB 121102, which has been observed in four series of bursts, the period of
orbiting of the body is about 200 days. Thermal radiation from the surface of
the star (temperature is of the order of $ 10^8 \, K $) causes evaporation and
ionization of the matter of the dense body. Ionized gas (plasma) flows around
the magnetosphere of the neutron star with the velocity $ u \simeq 10^7 \, cm /
s $, and creates electric potential $ \psi_0 \simeq 10^{11} \, V $ in the polar
region of the magnetosphere. Electrons from the plasma flow are accelerated
toward the star, and gain Lorentz factor of $ \simeq 10 ^ 5 $. Thermal photons
moving toward precipitating electrons are scattered by them, and produce gamma
photons with energies of $ \simeq 10^5 \, m_e c^2 $. These gamma quanta produce
electron-positron pairs in collisions with thermal photons. The multiplicity,
the number of born pairs per one primary electron, is about $ 10^5 $. The
electron-positron plasma, produced in the polar region of magnetosphere,
accumulates in a narrow layer at a bottom of a potential well formed on one
side by a blocking potential $ \psi_0 $, and on the other side by pressure of
thermal radiation. The density of electron-positron plasma in the layer
increases with time, and after short time the layer becomes a mirror for
thermal radiation of the star. The thermal radiation in the polar region under
the layer is accumulated during time $ \simeq 500 \, s $, then the plasma layer
is ejected outside. The ejection is observed as burst of radio emission formed
by the flow of relativistic electron-positron plasma.


  We present the first publicly released catalog of sources obtained from the
Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). HETDEX is an integral
field spectroscopic survey designed to measure the Hubble expansion parameter
and angular diameter distance at 1.88<z<3.52 by using the spatial distribution
of more than a million Ly-alpha-emitting galaxies over a total target area of
540 deg^2. The catalog comes from contiguous fiber spectra coverage of 25 deg^2
of sky from January 2017 through June 2020, where object detection is performed
through two complementary detection methods: one designed to search for line
emission and the other a search for continuum emission. The HETDEX public
release catalog is dominated by emission-line galaxies and includes 51,863
Ly{\alpha}-emitting galaxy (LAE) identifications and 123,891 OII-emitting
galaxies at z<0.5. Also included in the catalog are 37,916 stars, 5274
low-redshift (z<0.5) galaxies without emission lines, and 4976 active galactic
nuclei. The catalog provides sky coordinates, redshifts, line identifications,
classification information, line fluxes, OII and Ly-alpha line luminosities
where applicable, and spectra for all identified sources processed by the
HETDEX detection pipeline. Extensive testing demonstrates that HETDEX redshifts
agree to within deltaz < 0.02, 96.1% of the time to those in external
spectroscopic catalogs. We measure the photometric counterpart fraction in deep
ancillary Hyper Suprime-Cam imaging and find that only 55.5% of the LAE sample
has an r-band continuum counterpart down to a limiting magnitude of r~26.2 mag
(AB) indicating that an LAE search of similar sensitivity with photometric
pre-selection would miss nearly half of the HETDEX LAE catalog sample. Data
access and details about the catalog can be found online at http://hetdex.org/.


  We have fabricated a grating-gate InGaAs/GaAs field-effect transistor
structure with narrow slits between the grating gate fingers. The resonant
photoconductive response of this structure has been measured in the
sub-terahertz frequency range. The frequencies of the photoresponse peaks
correspond to the excitation of the plasmon resonances in the structure
channel. The obtained responsivity exceeds the responsivity reported previously
for similar plasmonic terahertz detectors by two orders of magnitude due to
enhanced coupling between incoming terahertz radiation and plasmon oscillations
in the slit-grating-gate field-effect transistor structure.


  We show that the second order traps in the control landscape for a
three-level $\Lambda$-system found in our previous work {\it Phys. Rev. Lett.}
{\bf 106}, 120402 (2011) are not local maxima: there exist directions in the
space of controls in which the objective grows. The growth of the objective is
slow --- at best 4th order for weak variations of the control. This implies
that simple gradient methods would be problematic in the vicinity of second
order traps, where more sophisticated algorithms that exploit the higher order
derivative information are necessary to climb up the control landscape
efficiently. The theory is supported by a numerical investigation of the
landscape in the vicinity of the $\varepsilon(t)=0$ second order trap,
performed using the GRAPE and BFGS algorithms.


  Strong-field ionization by counter-rotating two-color laser fields produces
quantum interference between photoelectrons emitted on the leading and trailing
edges of the laser field oscillations. We show that in chiral molecules, this
interference is asymmetric along the light propagation direction and strongly
enhances the sensitivity of the attoclock scheme to molecular chirality.
Calculations in a toy-model molecule with a short-range chiral potential show
that this enhanced sensitivity already emerges at the exit of the tunnel. We
investigate the possible sources of chiral sensitivity in the tunneling
process, and find that the interference between electron vortices plays a
crucial role in the chiral response.


  The second release of Gaia data (Gaia DR2) contains the astrometric
parameters for more than half a million quasars. This set defines a
kinematically non-rotating reference frame in the optical domain referred to as
the Gaia-CRF2. The Gaia-CRF2 is the first realisation of a non-rotating global
optical reference frame that meets the ICRS prescriptions, meaning that it is
built only on extragalactic sources. It consists of the positions of a sample
of 556 869 sources in Gaia DR2, obtained from a positional cross-match with the
ICRF3-prototype and AllWISE AGN catalogues. The sample constitutes a clean,
dense, and homogeneous set of extragalactic point sources in the magnitude
range G from 16 to 21 mag with accurately known optical positions. The median
positional uncertainty is 0.12 mas for G < 18 mag and 0.5 mas at G = 20 mag.
Large-scale systematics are estimated to be in the range 20 to 30 muas. The
accuracy claims are supported by the parallaxes and proper motions of the
quasars in Gaia DR2. The optical positions for a subset of 2820 sources in
common with the ICRF3-prototype show very good overall agreement with the radio
positions, but several tens of sources have significantly discrepant positions.


  The Simons Observatory (SO) is a cosmic microwave background (CMB)
observatory consisting of three small aperture telescopes and one large
aperture telescope. SO is located in the Atacama Desert in Chile at an
elevation of 5180m. Distributed among the four telescopes are over 60,000
transition-edge sensor (TES) bolometers across six spectral bands centered
between 27 and 280 GHz. A large collection of ancillary hardware devices which
produce lower rate `housekeeping' data are used to support the detector data
collection.
  We developed a distributed control system, which we call the observatory
control system (ocs), to coordinate data collection among all systems within
the observatory. ocs is a core component of the deployed site software,
interfacing with all on-site hardware. Alongside ocs we utilize a combination
of internally and externally developed open source projects to enable remote
monitoring, data management, observation coordination, and data processing.
  Deployment of a majority of the software is done using Docker containers. The
deployment of software packages is partially done via automated Ansible
scripts, utilizing a GitOps based approach for updating infrastructure on site.
We describe an overview of the software and computing systems deployed within
SO, including how those systems are deployed and interact with each other. We
also discuss the timing distribution system and its configuration as well as
lessons learned during the deployment process and where we plan to make future
improvements.


  Developer forums are one of the most popular and useful Q&A websites on API
usages. The analysis of API forums can be a critical resource for the automated
question and answer approaches. In this paper, we empirically study three API
forums including Twitter, eBay, and AdWords, to investigate the characteristics
of question-answering process. We observe that +60% of the posts on all three
forums were answered by providing API method names or documentation. +85% of
the questions were answered by API development teams and the answers from API
development teams drew fewer follow-up questions. Our results provide empirical
evidences for us in a future work to build automated solutions to answer
developer questions on API forums.


  Recently the reversible heat production during the electric double layer
(EDL) buildup in a sodium chloride solution was measured experimentally
[Janssen et al., Phys. Rev. Lett. 119, 166002 (2017)] and matched with
theoretical predictions from density functional theory and molecular dynamics
simulations [Glatzel et al., J. Chem. Phys. 154, 064901 (2021)]. In the latter,
it was found that steric interactions of ions with the electrode's walls, which
result in the so-called Stern layer, are sufficient to explain the experimental
results. As only symmetric ion sizes in a restricted primitive model were
examined, it is instructive to investigate systems of unequal ion sizes that
lead to modified Stern layers. In this work, we explore the impact of ion
asymmetry on the reversible heat production for each electrode separately. In
this context, we further study an extension of the primitive model where
hydration shells of ions can evade in the vicinity of electrode's walls. We
find a strong dependence on system parameters such as the particle sizes and
the total volume taken by particles. Here, we even found situations where one
electrode was heated and the other electrode was cooled at the same time during
charging, while, in sum, both electrodes together behaved very similarly to the
already mentioned experimental results. Thus, heat production should also be
measured in experiments for each electrode separately. By this, the importance
of certain ingredients that we proposed to model electrolytes could be
confirmed or ruled out experimentally, finally leading to a deeper
understanding of the physics of EDLs.


  The difficulty in frequency domain identification is that frequency
components of arbitrary inputs and outputs are not related by the system's
transfer function if signals are windowed. When rectangular windows are used,
it is well known that this difference is related to transient effects that can
be estimated alongside the systems' parameters windows. In this work, we
generalize the approach for arbitrary windows, showing that signal windowing
introduces additional terms in the system's equations. The formalism is useful
for frequency-domain input-output analysis of a system, and also for system
identification. For the latter application, the approach considerably reduces
aliasing effects and allows the computation of the associated correction terms,
reducing the number of parameters that need to be estimated. The system
identification approach has features of the modulating-function technique,
filtering out the effects of initial conditions while retaining the spectral
interpretation of frequency-domain methods.


  First responders and other forward deployed essential workers can benefit
from advanced analytics. Limited network access and software security
requirements prevent the usage of standard cloud based microservice analytic
platforms that are typically used in industry. One solution is to precompute a
wide range of analytics as files that can be used with standard preinstalled
software that does not require network access or additional software and can
run on a wide range of legacy hardware. In response to the COVID-19 pandemic,
this approach was tested for providing geo-spatial census data to allow quick
analysis of demographic data for better responding to emergencies. These data
were processed using the MIT SuperCloud to create several thousand Google Earth
and Microsoft Excel files representative of many advanced analytics. The fast
mapping of census data using Google Earth and Microsoft Excel has the potential
to give emergency responders a powerful tool to improve emergency preparedness.
Our approach displays relevant census data (total population, population under
15, population over 65, median age) per census block, sorted by county, through
a Microsoft Excel spreadsheet (xlsx file) and Google Earth map (kml file). The
spreadsheet interface includes features that allow users to convert between
different longitude and latitude coordinate units. For the Google Earth files,
a variety of absolute and relative colors maps of population density have been
explored to provide an intuitive and meaningful interface. Using several
hundred cores on the MIT SuperCloud, new analytics can be generated in a few
minutes.


  The Transformer architecture is shown to provide a powerful machine
transduction framework for online handwritten gestures corresponding to glyph
strokes of natural language sentences. The attention mechanism is successfully
used to create latent representations of an end-to-end encoder-decoder model,
solving multi-level segmentation while also learning some language features and
syntax rules. The additional use of a large decoding space with some learned
Byte-Pair-Encoding (BPE) is shown to provide robustness to ablated inputs and
syntax rules. The encoder stack was directly fed with spatio-temporal data
tokens potentially forming an infinitely large input vocabulary, an approach
that finds applications beyond that of this work. Encoder transfer learning
capabilities is also demonstrated on several languages resulting in faster
optimisation and shared parameters. A new supervised dataset of online
handwriting gestures suitable for generic handwriting recognition tasks was
used to successfully train a small transformer model to an average normalised
Levenshtein accuracy of 96% on English or German sentences and 94% in French.


  We discuss a new type of unitary perturbations around conformal theories
inspired by the $\sigma$-model perturbation of the nonunitary WZNW model. We
show that the nonunitary level $k$ WZNW model perturbed by its sigma model term
goes to the unitary level $-k$ WZNW model. When plugged into the gauged WZNW
model the given perturbation results in the perturbed gauged WZNW model which
no longer describes a coset construction. We consider the BRST invariant
generalization of the sigma model perturbation around the gauged WZNW model. In
this way we obtain perturbed coset constructions. In the case of the
$SU_{m-2}(2)\times SU_1(2)/SU_{m-1}(2)$ coset, the BRST invariant sigma model
perturbation is identical to Zamolodchikov's $\Phi_{(3,1)}$ perturbation of the
minimal conformal series. The existence of general geometry flows is clarified.


  We consider cosmological consequences of a heavy axino, decaying to the
neutralino in R-parity conserving models. The importance and influence of the
axino decay on the resultant abundance of neutralino dark matter depends on the
lifetime and the energy density of axino. For a high reheating temperature
after inflation, copiously produced axinos dominate the energy density of the
universe and its decay produces a large amount of entropy. As a bonus, we
obtain that the upper bound on the reheating temperature after inflation via
gravitino decay can be moderated, because the entropy production by the axino
decay more or less dilutes the gravitinos.


  We report on the trapping of ultracold atoms in the magnetic field formed
entirely by persistent supercurrents induced in a thin film type-II
superconducting square. The supercurrents are carried by vortices induced in
the 2D structure by applying two magnetic field pulses of varying amplitude
perpendicular to its surface. This results in a self-sufficient quadrupole trap
that does not require any externally applied fields. We investigate the
trapping parameters for different supercurrent distributions. Furthermore, to
demonstrate possible applications of these types of supercurrent traps we show
how a central quadrupole trap can be split into four traps by the use of a bias
field.


  Metasurfaces with subwavelength thickness have exhibited unconventional
phenomena in ways that could not be mimicked by traditional materials. Here we
report the analytical design and experimental realizations of acoustic
metasurface with hitherto inaccessible functionality of manipulating the
reflected waves arbitrarily. By suitably designing the phase shift profile
covering 2 range induced by labyrinthine units, the metasurface can reflect
acoustic waves in an unusual yet controllable manner. Anomalous reflection and
ultrathin planar lens with adjustable focal point were both demonstrated with
carefully designed metasurfaces. Remarkably, the free manipulation of phase
shifts offers great flexibility in the design of non-paraxial or paraxial
acoustic self-accelerating beams with arbitrary trajectories. With the
extraordinary wave-steering ability, the metasurface should open exciting
possibilities for designing compact acoustic components with versatile
potential and may find a variety of applications ranging from ultrasound
imaging to field caustic engineering.


  Excess hazard modeling is one of the main tools in population-based cancer
survival research. Indeed, this setting allows for direct modeling of the
survival due to cancer even in the absence of reliable information on the cause
of death, which is common in population-based cancer epidemiology studies. We
propose a unifying link-based additive modeling framework for the excess hazard
that allows for the inclusion of many types of covariate effects, including
spatial and time-dependent effects, using any type of smoother, such as thin
plate, cubic splines, tensor products and Markov random fields. In addition,
this framework accounts for all types of censoring as well as left-truncation.
Estimation is conducted by using an efficient and stable penalized
likelihood-based algorithm whose empirical performance is evaluated through
extensive simulation studies. Some theoretical and asymptotic results are
discussed. Two case studies are presented using population-based cancer data
from patients diagnosed with breast (female), colon and lung cancers in
England. The results support the presence of non-linear and time-dependent
effects as well as spatial variation. The proposed approach is available in the
R package GJRM.


  We develop a classically verifiable scheme for blindly factorizing the
semiprime 21 quantumly for a classical client who does not trust the remote
quantum servers. Our scheme advances state of the art, which achieves blind
factorization of 15 quantumly, by increasing the problem to factorizing the
next semiprime, choosing a harder base, executing a non-Clifford gate, and
showing that the security check for 15 also works for 21. Our algorithmic
approach to incorporating non-Clifford operations sets the stage for scaling
blind quantum factorization, whereas our five-EPR-pair scheme motivates a
photonic experiment that supplants current demonstrations of blind
factorization.


  Cities generate gains from interaction, but citizens often experience
segregation as they move around the urban environment. Using GPS location data,
we identify four distinct patterns of experienced segregation across US cities.
Most common are affluent or poor neighborhoods where visitors lack diversity
and residents have limited exposure to diversity elsewhere. Less frequent are
majority-minority areas where residents must travel for diverse encounters, and
wealthy urban zones with diverse visitors but where locals sort into
homogeneous amenities. By clustering areas with similar mobility signatures, we
uncover rings around cities and internal pockets where intergroup interaction
is limited. Using a decision tree, we show that demography and location
interact to create these zones. Our findings, persistent across time and
prevalent across US cities, highlight the importance of considering both who is
mixing and where in urban environments. Understanding the mesoscopic patterns
that define experienced segregation in America illuminates neighborhood
advantage and disadvantage, enabling interventions to foster economic
opportunity and urban dynamism.


  Interference alignment is a key technique for communication scenarios with
multiple interfering links. In several such scenarios, interference alignment
was used to characterize the degrees-of-freedom of the channel. However, these
degrees-of-freedom capacity approximations are often too weak to make accurate
predictions about the behavior of channel capacity at finite signal-to-noise
ratios (SNRs). The aim of this paper is to significantly strengthen these
results by showing that interference alignment can be used to characterize
capacity to within a constant gap. We focus on real, time-invariant,
frequency-flat X-channels. The only known solutions achieving the
degrees-of-freedom of this channel are either based on real interference
alignment or on layer-selection schemes. Neither of these solutions seems
sufficient for a constant-gap capacity approximation.
  In this paper, we propose a new communication scheme and show that it
achieves the capacity of the Gaussian X-channel to within a constant gap. To
aid in this process, we develop a novel deterministic channel model. This
deterministic model depends on the 0.5log(SNR) most-significant bits of the
channel coefficients rather than only the single most-significant bit used in
conventional deterministic models. The proposed deterministic model admits a
wider range of achievable schemes that can be translated to the Gaussian
channel. For this deterministic model, we find an approximately optimal
communication scheme. We then translate this scheme for the deterministic
channel to the original Gaussian X-channel and show that it achieves capacity
to within a constant gap. This is the first constant-gap result for a general,
fully-connected network requiring interference alignment.


  Dirac Spin liquids (DSLs) are gapless featureless states, yet interesting by
virtue of the effective field theory describing them -- (2+1)-dimensional
quantum electrodynamics (QED$_3$). Further, a DSL is known to be a "parent
state" of various seemingly unrelated ordered states, such as antiferromagnets
and valence bond solids in the sense that one can obtain ordered states by
condensing magnetic monopoles of the emergent gauge field. Can operators in the
effective field theory, such as the emergent electric field, be externally
induced and measured? In this work, we exploit the parent state picture to
argue that the answer is yes. We propose a range of "monopole Josephson
effects" that arise when two ordered states are separated by a region of the
parent DSL. In particular, we show that one can induce an AC monopole Josephson
effect, which manifests itself as an AC emergent electric field in the spin
liquid, accompanied by a measurable spin current. Further, we show that this AC
emergent electric field can be measured as a sharp tunable peak in Raman
scattering. This work provides a theoretical proof of principle that emergent
gauge fields in spin liquids can be externally induced, manipulated, and probed
using more conventional states, which offers a generic platform for studying
the exotic spin phases.


  Disordered magnets, martensitic mixed crystals, and glassy solids can be
irreversibly deformed by subjecting them to external deformation. The
deformation produces a smooth, reversible response punctuated by abrupt
relaxation "glitches". Under appropriate repeated forward and reverse
deformation producing multiple glitches, a strict repetition of a single
sequence of microscopic configurations often emerges. We exhibit these features
by describing the evolution of the system configuration from glitch to glitch
as a mapping of $\mathcal{N}$ states into one-another. A map $\mathbf{U}$
controls forward deformation; a second map $\mathbf{D}$ controls reverse
deformation. Iteration of a given sequence of forward and reverse maps, e.g.
$\mathbf{DDDDUUU}$ necessarily produces a convergence to a fixed cyclic
repetition of states covering multiple glitches. The repetition may have a
period of more than one strain cycle, as recently observed in simulations.
Using numerical sampling, we characterize the convergence properties of four
types of random maps implementing successive physical restrictions. The most
restrictive is the much-studied Preisach model. These maps show only the most
qualitative resemblance to annealing simulations. However, they suggest further
properties needed for a realistic mapping scheme.