  The Schroedinger eigenvalue problems for the Whittaker-Hill potential
$Q_{2}(x)=\tfrac{1}{2} h^2\cos4x+4h\mu\cos2x$ and the periodic complex
potential $Q_{1}(x)=\tfrac{1}{4}h^2{\rm e}^{-4ix}+2h^2\cos2x$ are studied using
their realizations in two-dimensional conformal field theory (2dCFT). It is
shown that for the weak coupling (small) $h\in\mathbb{R}$ and non-integer
Floquet parameter $\nu\notin\mathbb{Z}$ spectra of hamiltonians
$H_{i}\!=\!-{\rm d}^2/{\rm d}x^2 + Q_{i}(x)$, $i=1,2$ and corresponding two
linearly independent eigenfunctions are given by the classical limit of the
"single flavor" and "two flavors" ($N_f=1,2$) irregular conformal blocks. It is
known that complex non-hermitian hamiltonians which are PT-symmetric (=
invariant under simultaneous parity P and time reversal T transformations) can
have real eigenvalues. The hamiltonian $H_{1}$ is PT-symmetric for
$h,x\in\mathbb{R}$. It is found that $H_{1}$ has a real spectrum in the weak
coupling region for $\nu\in\mathbb{R}\setminus\mathbb{Z}$. This fact in an
elementary way follows from a definition of the $N_f=1$ classical irregular
block. Thus, $H_{1}$ can serve as yet another new model for testing postulates
of PT-symmetric quantum mechanics.


  Northeast China is the learding food productive base of China. The extreme
precipitation (EP) event seriously impacts agricultural production and social
life. Given the limited understanding of the EP in Northeast China, we
investigate the trend and potential risk of the EP in Northeast China(107
stations) during 1959-2017, especially in early and later summer. For the first
time, the non-stationary generalized extreme value (GEV) model is used to
analyze the trend and potential risk of EP in Northeast China. Moreover, the
mechanisms of EP trends over Northeast China in early and later summer were
studied separately. Negative trends dominate EP in early summer but positive
trends prevail in last summer. It is reasonable to discuss separately in the
two periods. Meanwhile, all return levels are shown to increase trends in EP in
early summer, corresponding to more frequent EP events. Nevertheless, in later
summer, the 2-year return level decreases in location parameter diminish
slightly, and the rare EP (20, 50, and 100-year return levels) slightly
increase with scale parameter. Also, our results show that normal EP frequently
occurs in Liaoning Province, and extreme EP is more likely to occur in Jilin
Province and Heilongjiang Province. The increase of EP in early summer is
mainly influenced by the northeast cold vortex. However, in later summer, the
effect of cold air on EP is stronger in Northeast China, which gives a clear
explanation that the EP does not increase. This study analyzed the trends and
mechanism of return level and EP, which is beneficial for the development of
policy strategies.


  The developments of Rademacher complexity and PAC-Bayesian theory have been
largely independent. One exception is the PAC-Bayes theorem of Kakade,
Sridharan, and Tewari (2008), which is established via Rademacher complexity
theory by viewing Gibbs classifiers as linear operators. The goal of this paper
is to extend this bridge between Rademacher complexity and state-of-the-art
PAC-Bayesian theory. We first demonstrate that one can match the fast rate of
Catoni's PAC-Bayes bounds (Catoni, 2007) using shifted Rademacher processes
(Wegkamp, 2003; Lecu\'{e} and Mitchell, 2012; Zhivotovskiy and Hanneke, 2018).
We then derive a new fast-rate PAC-Bayes bound in terms of the "flatness" of
the empirical risk surface on which the posterior concentrates. Our analysis
establishes a new framework for deriving fast-rate PAC-Bayes bounds and yields
new insights on PAC-Bayesian theory.


  Locality is analyzed for Toda field theories by noting novel chiral
description in the conventional nonchiral formalism. It is shown that the
canonicity of the interacting to free field mapping described by the classical
solution is automatically guaranteed by the locality. Quantum Toda theories are
investigated by applying the method of free field quantization. We give Toda
exponential operators associated with fundamental weight vectors as bilinear
forms of chiral fields satisfying characteristic quantum exchange algebra. It
is shown that the locality leads to nontrivial relations among the ${\cal
R}$-matrix and the expansion coefficients of the exponential operators. The
Toda exponentials are obtained for $A_2$-system by extending the algebraic
method developed for Liouville theory. The canonical commutation relations and
the operatorial field equations are also examined.


  We study effects of CP violation in an associated production of a charged
Higgs boson and a top quark at the LHC: $pp \to tH^\pm +X$. We calculate the CP
violating asymmetry between the total cross section for $H^+$ and $H^-$
production at next-to-leading order in the MSSM, and perform a detailed
numerical analysis. In the production only the asymmetry is of the order of
20%. The asymmetry in the production and any subsequent decay of an on-shell
charged Higgs boson is to a good approximation the sum of the asymmetry in the
production and the asymmetry in the decay. We consider subsequent decays of
$H^\pm $ to $tb$, $\nu_\tau \tau^\pm$ and $Wh^0$. In the case of subsequent
$H^\pm \to tb$ decay, the $W^\pm - H^\pm$ self energy contributions from the
production and the decay cancel. However, the remaining effect, mainly due to
CP violating box graphs with gluino can go up to $\sim 13$%.


  We examine the combined effects of winds and photoionizing radiation from
O--type stars on embedded stellar clusters formed in model turbulent molecular
clouds covering a range of masses and radii. We find that feedback is able to
increase the quantities of dense gas present, but decreases the rate and
efficiency of the conversion of gas to stars relative to control simulations in
which feedback is absent. Star formation in these calculations often proceeds
at a rate substantially slower than the freefall rate in the dense gas. This
decoupling is due to the weakening of, and expulsion of gas from, the deepest
parts of the clouds' potential wells where most of the star formation occurs in
the control simulations. This results in large fractions of the stellar
populations in the feedback simulation becoming dissociated from dense gas.
However, where star formation \emph{does} occur in both control and feedback
simulations, it does so in dense gas, so the correlation between star formation
activity and dense gas is preserved. The overall dynamical effects of feedback
on the \emph{clusters} are minimal, with only small fraction of stars becoming
unbound, despite large quantities of gas being expelled from some clouds. This
owes to the settling of the stars into virialised and stellar--dominated
configurations before the onset of feedback. By contrast, the effects of
feedback on the observable properties of the clusters -- their U--, B-- and
V--band magnitudes -- are strong and sudden. The timescales on which the
clusters become visible and unobscured are short compared with the timescales
which the clouds are actually destroyed.


  I compiled a list of articles on arXiv that deal with possible fundamental
quantum nonlinearities or examine the origins of its linearity. The list
extends til August 2004.


  While the third run of the Large Hadron Collider (LHC) is ongoing, the
underlying theory that extends the Standard Model remains so far unknown.
Left-Right Models (LRMs) introduce a new gauge sector, and can restore parity
symmetry at high enough energies. If LRMs are indeed realized in nature, the
mediators of the new weak force can be searched for in colliders via their
direct production. We recast existing experimental bounds from LHC Run 2 on the
heavy LRM gauge boson masses. As a novelty, we discuss the effect of the LRM
scalar content on the total width of the new gauge bosons, obtaining
model-independent bounds within the specific realizations of the LRM scalar
sectors analysed here. These bounds avoid the need to detail the spectrum of
the scalar sector, and apply in the general case where no discrete symmetry is
enforced. Moreover, we emphasize the effect of the structure of the quark
right-handed mixing matrix on the charged LRM gauge boson production at LHC. We
find that $W_R$ and $Z_R$ masses are constrained to lie above $2$ TeV and $4$
TeV, respectively.


  The three-dimensional XY model is studied at finite chemical potential using
complex Langevin dynamics. The validity of the approach is probed at small
chemical potential using imaginary chemical potential and continuity arguments,
and at larger chemical potential by comparison with the world line method.
While complex Langevin works for larger beta, we find that it fails for smaller
beta, in the region of the phase diagram corresponding to the disordered phase.
Diagnostic tests are developed to identify symptoms correlated with incorrect
convergence. We argue that the erroneous behaviour at smaller beta is not due
to the sign problem, but rather resembles dynamics observed in complex Langevin
simulations of simple models with complex noise.


  This work investigates Monte-Carlo planning for agents in stochastic
environments, with multiple objectives. We propose the Convex Hull Monte-Carlo
Tree-Search (CHMCTS) framework, which builds upon Trial Based Heuristic Tree
Search and Convex Hull Value Iteration (CHVI), as a solution to multi-objective
planning in large environments. Moreover, we consider how to pose the problem
of approximating multiobjective planning solutions as a contextual multi-armed
bandits problem, giving a principled motivation for how to select actions from
the view of contextual regret. This leads us to the use of Contextual Zooming
for action selection, yielding Zooming CHMCTS. We evaluate our algorithm using
the Generalised Deep Sea Treasure environment, demonstrating that Zooming
CHMCTS can achieve a sublinear contextual regret and scales better than CHVI on
a given computational budget.


  This paper suggests integrating one-dimensional optimization methods to
tackle diverse problems, emphasizing their significance in resolving practical
issues and applying mathematical principles to real-world contexts. It focuses
on employing the Octave programming language, backed by specific examples, to
simplify the practical application of mathematical concepts and improve
problem-solving abilities. The research aims to assess the effect on students'
comprehension of one-dimensional optimization.


  We analyze and optimize a wireless system with energy transfer in the
downlink and information transfer in the uplink, under quasi-static Nakagami-m
fading. We consider ultra-reliable communication scenarios representative of
the fifth-generation of wireless systems, with strict error and latency
requirements. The error probability and delay are investigated, and an
approximation for the former is given and validated through simulations. The
numerical results demonstrate that there are optimum numbers of channels uses
for both energy and information transfer for a given message length.


  Results of LSDA and LSDA+U calculations of the electronic structure and
magnetic configurations of the 50% hole-doped pseudocubic perovskite
La0.5Sr0.5MnO3 and double layered LaSr2Mn2O7 are presented. We demonstrate that
the on-site Coulomb correlation (U) of Mn d electrons has a very different
influence on the (i) band formations, (ii) magnetic ground states, (iii)
interlayer exchange interactions, and (iv) anisotropy of the electrical
transport in these two manganites. A possible reason why the LSDA failures in
predicting observed magnetic and transport properties of the double layered
compound - in contrast to the doped perovskite manganite - is considered on the
basis of a p-d hybridization analysis.


  Vector Approximate Message Passing (VAMP) provides the means of solving a
linear inverse problem in a Bayes-optimal way assuming the measurement operator
is sufficiently random. However, VAMP requires implementing the linear minimum
mean squared error (LMMSE) estimator at every iteration, which makes the
algorithm intractable for large-scale problems. In this work, we present a
class of warm-started (WS) methods that provides a scalable approximation of
LMMSE within VAMP. We show that a Message Passing (MP) algorithm equipped with
a method from this class can converge to the fixed point of VAMP while having a
per-iteration computational complexity proportional to that of AMP.
Additionally, we provide the Onsager correction and a multi-dimensional State
Evolution for MP utilizing one of the WS methods. Lastly, we show that the
approximation approach used in the recently proposed Memory AMP (MAMP)
algorithm is a special case of the developed class of WS methods.


  We explore the geometric interpretation of a diabatic, two-photon Raman
process as a rotation on the Bloch sphere for a pseudo-spin-1/2 system. The
spin state of a spin-1/2 quantum system can be described by a point on the
surface of the Bloch sphere, and its evolution during a Raman pulse is a
trajectory on the sphere determined by properties of the optical beams: the
pulse area, the relative intensities and phases, and the relative frequencies.
We experimentally demonstrate key features of this model with a $^{87}$Rb
spinor Bose-Einstein condensate, which allows us to examine spatially dependent
signatures of the Raman beams. The two-photon detuning allows us to precisely
control the spin density and imprinted relative phase profiles, as we show with
a coreless vortex. With this comprehensive understanding and intuitive
geometric interpretation, we use the Raman process to create and tailor as well
as study and characterize exotic topological spin textures in spinor BECs.


  We analyze and demonstrate, numerically and experimentally, the self-healing
effect in scaled propagation invariant beams, subject to opaque obstructions.We
introduce the signal to noise intensity ratio, a semi-analytical figure of
merit, explicitly dependent on the features of the beams and the obstructions
applied to them. The effect is quantitatively evaluated employing the Root Mean
Square deviation and the similarity function.


  The old quantum theory of Bohr and Sommerfeld was abandonned for the wrong
reason. Its contradictions were caused not by the orbit concept but by a mental
barrier--the inconceivability that an electron might collide with the atomic
nucleus. Removing that barrier resolves the theory's main failures--incorrect
orbital momenta, He atom, H2+ molecule ion. The inclusion of electron
oscillations through the nucleus--a concept called "Coulomb
oscillator"--renders the old quantum theory consistent with quantum mechanics
(although devoid of wave character). The triple success of the Bohr-Sommerfeld
model is its correct description of the H atom (and one-electron ions)
concerning (1) the energy levels Enl, (2) the orbital angular momenta Lnl--if
corrected as Lnl^2 = l(l+1) hbar^2 and with the Coulomb oscillator
included--and (3) the orbits' space quantization--with (Lnl)z = ml hbar. These
achievements are succinctly represented by the principal, angular and magnetic
quantum numbers (n, l, ml) and visualized by orbital ellipse geometry--major
axis, vertex curvature, and tilt angle, respectively. Orbit geometry also
accounts for the average orbit size. Moreover, the Coulomb oscillator provides
a natural explanation of (isotropic) hyperfine interaction. The shortcomings of
the old quantum theory lie in its neglect of three properties of
particles--their spin, their wave nature and their quantum statistics. These
deficiencies notwithstanding, the visual appeal of the Bohr-Sommerfeld model
remains a pedagogical asset to complement the abstract character of quantum
mechanics.


  This paper illustrates a unified approach, classical circuit and control
theories, to study a nonlinear LC circuit with a current dependent inductance
as model of the Josephson junction, the mathematical analysis is complemented
with simulations to visualize different dynamics under changes in parameters
and inputs. Currently, in quantum computing, superconducting circuits with
Josephson junctions are used as the building blocks of quantum bits or qubits.


  Boundary value problems for integrable nonlinear partial differential
equations are considered from the symmetry point of view. Families of boundary
conditions compatible with the Harry-Dym, KdV and MKdV equations and the
Volterra chain are discussed. We also discuss the uniqueness of some of these
boundary conditions.


  This paper concerns the lattice $L_n$ of subsets of $\{1,\ldots,n\}$ that are
arithmetic progressions, under the inclusion order. For $n\geq 4$, this poset
is not graded and thus not semimodular. We give three independent proofs of the
fact that for $n\geq 2$, $\mu_n(L_n) = \mu(n-1)$, where $\mu_n$ is the M\"obius
function of $L_n$ and $\mu$ is the classical (number-theoretic) M\"obius
function. We also show that $L_n$ is comodernistic, which implies that $L_n$ is
EL-labelable. Comodernism is then used to prove that the order complex
$\Delta_n$ of the lattice is either contractible or homotopy equivalent to a
sphere.


  The beta-decay half-life of 62Ga has been studied with high precision using
on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to
0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} =
116.19(4) ms. This result is more precise than any previous measurement by
about a factor of four or more. The present value is in agreement with older
literature values, but slightly disagrees with a recent measurement. We
determine an error weighted average value of all experimental half-lives of
116.18(4) ms.


  Computerized Adaptive Testing(CAT) refers to an online system that adaptively
selects the best-suited question for students with various abilities based on
their historical response records. Most CAT methods only focus on the quality
objective of predicting the student ability accurately, but neglect concept
diversity or question exposure control, which are important considerations in
ensuring the performance and validity of CAT. Besides, the students' response
records contain valuable relational information between questions and knowledge
concepts. The previous methods ignore this relational information, resulting in
the selection of sub-optimal test questions. To address these challenges, we
propose a Graph-Enhanced Multi-Objective method for CAT (GMOCAT). Firstly,
three objectives, namely quality, diversity and novelty, are introduced into
the Scalarized Multi-Objective Reinforcement Learning framework of CAT, which
respectively correspond to improving the prediction accuracy, increasing the
concept diversity and reducing the question exposure. We use an Actor-Critic
Recommender to select questions and optimize three objectives simultaneously by
the scalarization function. Secondly, we utilize the graph neural network to
learn relation-aware embeddings of questions and concepts. These embeddings are
able to aggregate neighborhood information in the relation graphs between
questions and concepts. We conduct experiments on three real-world educational
datasets, and show that GMOCAT not only outperforms the state-of-the-art
methods in the ability prediction, but also achieve superior performance in
improving the concept diversity and alleviating the question exposure. Our code
is available at https://github.com/justarter/GMOCAT.


  Complex networks have certain properties that distinguish them from their
respective uniform or regular counterparts. One of these properties is the
variation of topological properties along different hierarchical levels. In
this work, we study how networks that are constructed by repeatedly
incorporating a given motif exhibit this property. A motif is henceforth
understood as a small subgraph with a reference node where the incorporation
respectively occurs. We generate fractal networks using different motifs and
observe how their topology changes depending along the growth stages. Two
regimes are respectively identified: transient and equilibrium. The former is
characterized by significant topological changes that depend on the motif
topology, while the equilibrium regime shows more stable, parallel
trajectories. A more systematic analysis revealed that the betweenness
centrality and the average shortest path lengths were the main topological
properties that change along the network growth.


  We consider the following question posted by K.I. Beidar and A.V. Mikhalev in
1995 for an associative ring $R=R_1+R_2$: is it true that if the subrings $R_1$
and $R_2$ satisfy polynomial identities, then $R$ also satisfies a polynomial
identity? Over a field of positive characteristic we establish new conditions
on $R_1$ and $R_2$ that guarantee a positive answer to the question. We find
upper and low bounds on the degrees of identities of $R$.


  We address the problem of finding a wombling boundary in point data generated
by a general Poisson point process, a specific example of which is an LHC event
sample distributed in the phase space of a final state signature, with the
wombling boundary created by some new physics. We discuss the use of Voronoi
and Delaunay tessellations of the point data for estimating the local gradients
and investigate methods for sharpening the boundaries by reducing the
statistical noise. The outcome from traditional wombling algorithms is a set of
boundary cell candidates with relatively large gradients, whose spatial
properties must then be scrutinized in order to construct the boundary and
evaluate its significance. Here we propose an alternative approach where we
simultaneously form and evaluate the significance of all possible boundaries in
terms of the total gradient flux. We illustrate our method with several toy
examples of both straight and curved boundaries with varying amounts of signal
present in the data.


  Large-scale density functional theory (DFT) calculations provide a powerful
tool to investigate the atomic and electronic structure of materials with
complex structures. This article reviews a large-scale DFT calculation method,
the multi-site support function (MSSF) method, in the CONQUEST code. MSSFs are
linear combinations of the basis functions which belong to a group of atoms in
a local region. The method can reduce the computational time while preserving
accuracy. The accuracy of MSSFs has been assessed for bulk Si, Al, Fe and NiO
and hydrated DNA, which demonstrate the applicability of the MSSFs for varied
materials. The applications of MSSFs on large systems with several thousand
atoms, which have complex interfaces and non-periodic structures, indicate that
the MSSF method is promising for precise investigations of materials with
complex structures.


  We consider moderately interacting particle systems with singular interaction
kernel and environmental noise. It is shown that the mollified empirical
measures converge in strong norms to the unique (local) solutions of nonlinear
Fokker-Planck equations. The approach works for the Biot-Savart and repulsive
Poisson kernels.


  In a recent work we presented a reformulation of the canonical quantum
gravity, based on adding the so-called kinematical term to the gravity-matter
action; this revised approach leads to a self-consistent canonical quantization
of the 3-geometries, referred to the external time as provided via the added
term.
  Here, we show how the kinematical term can be interpreted in terms of a non
relativistic dust fluid which plies the role of a ``real clock' for the quantum
gravity theory, and, in the WKB limit of a cosmological problem, makes account
for a dark matter component which, at present time, could play a dynamical
role.


  One of the primary goals of nuclear physics is providing a complete
description of the structure of atomic nuclei. While mean-field calculations
provide detailed information on the nuclear shell structure for a wide range of
nuclei, they do not capture the complete structure of nuclei, in particular the
impact of small, dense structures in nuclei. The strong, short-range component
of the nucleon-nucleon potential yields hard interactions between nucleons
which are close together, generating a high-momentum tail to the nucleon
momentum distribution, with momenta well in excess of the Fermi momentum. This
high-momentum component of the nuclear wave-function is one of the most poorly
understood parts of nuclear structure.
  Utilizing high-energy probes, we can isolate scattering from high-momentum
nucleons, and use these measurements to examine the structure and impact of
short-range nucleon-nucleon correlations. Over the last decade we have moved
from looking for evidence of such short-range structures to mapping out their
strength in nuclei and examining their isospin structure. This has been made
possible by high-luminosity and high-energy accelerators, coupled with an
improved understanding of the reaction mechanism issues involved in studying
these structures. We review the general issues related to short-range
correlations, survey recent experiments aimed at probing these short-range
structures, and lay out future possibilities to further these studies.


  Forecasting with multivariate time series, which aims to predict future
values given previous and current several univariate time series data, has been
studied for decades, with one example being ARIMA. Because it is difficult to
measure the extent to which noise is mixed with informative signals within
rapidly fluctuating financial time series data, designing a good predictive
model is not a simple task. Recently, many researchers have become interested
in recurrent neural networks and attention-based neural networks, applying them
in financial forecasting. There have been many attempts to utilize these
methods for the capturing of long-term temporal dependencies and to select more
important features in multivariate time series data in order to make accurate
predictions. In this paper, we propose a new prediction framework based on deep
neural networks and a trend filtering, which converts noisy time series data
into a piecewise linear fashion. We reveal that the predictive performance of
deep temporal neural networks improves when the training data is temporally
processed by a trend filtering. To verify the effect of our framework, three
deep temporal neural networks, state of the art models for predictions in time
series finance data, are used and compared with models that contain trend
filtering as an input feature. Extensive experiments on real-world multivariate
time series data show that the proposed method is effective and significantly
better than existing baseline methods.


  We examine the three-step master equation from the standpoint of the general
solution of the associated discrete Riccati equation. We report by this means
stationary master solutions depending on a free constant parameter, denoted by
D, that should be negative in order to assure the positivity of the solution.
These solutions correspond to different discrete Markov processes characterized
by the value of D, which is related to specific renormalizations of the
transition rates of the chain of states


  We argue that the cosmic microwave background (CMB) provides a stupendous
opportunity for the Creator of universe our (assuming one exists) to have sent
a message to its occupants, using known physics. Our work does not support the
Intelligent Design movement in any way whatsoever, but asks, and attempts to
answer, the entirely scientific question of what the medium and message might
be IF there was actually a message. The medium for the message is unique. We
elaborate on this observation, noting that it requires only careful adjustment
of the fundamental Lagrangian, but no direct intervention in the subsequent
evolution of the universe.


  We explain the connection between the generalized spin quantities we have
recently introduced and standard forms. We show how the calculation of various
quantities of interest using these new forms is done. Focusing attention on
expectation values, we find that in every case, the standard results can be
obtained as special cases arising from the new generalized results.


  Describing the gravitational energy and momentum, the Bel-Robinson tensor is
the best tensor. However, the classical pseudotensors can also manage the the
same job. As Deser mentioned in 1999, a certain linear combination between
Einstein pseudotensor and Landau-Lifshitz pseudoetnsor give a pure Bel-Robinson
tensor. Here we used the same idea but adapted the harmonic gauge, we found
that all the classical pseudotensor alone cannot give a multiple of the
Bel-Robinson tensor. But under a modification, all of them contribute the same
energy-momentum and stress as the Bel-Robinson tensor does.


  A novel approach to automated learning of syntactic rules governing natural
languages is proposed, based on using probabilities assigned to sentences (and
potentially longer word sequences) by transformer neural network language
models to guide symbolic learning processes like clustering and rule induction.
This method exploits the learned linguistic knowledge in transformers, without
any reference to their inner representations; hence, the technique is readily
adaptable to the continuous appearance of more powerful language models. We
show a proof-of-concept example of our proposed technique, using it to guide
unsupervised symbolic link-grammar induction methods drawn from our prior
research.


  Reaching gigagauss magnetic fields opens new horizons both in atomic and
plasma physics. At these magnetic field strengths, the electron cyclotron
energy $\hbar\omega_{c}$ becomes comparable to the atomic binding energy (the
Rydberg), and the cyclotron frequency $\omega_{c}$ approaches the plasma
frequency at solid state densities that significantly modifies optical
properties of the target. The generation of such strong quasistatic magnetic
fields in laboratory remains a challenge. Using supercomputer simulations, we
demonstrate how it can be achieved all-optically by irradiating a micro-channel
target by a circularly polarized relativistic femtosecond laser. The laser
pulse drives a strong electron vortex along the channel wall, inducing a
megagauss longitudinal magnetic field in the channel by the inverse Faraday
effect. This seed field is then amplified up to a gigagauss level and
maintained on a picosecond time scale via dynamos driven by plasma thermal
expansion off the channel walls. Our scheme sets a possible platform for
producing long living extreme magnetic fields in laboratories using readily
available lasers. The concept might also be relevant for applications such as
magneto-inertial fusion.


  Generative artificial intelligence (AI) is a widely popular technology that
will have a profound impact on society and individuals. Less than a decade ago,
it was thought that creative work would be among the last to be automated - yet
today, we see AI encroaching on many creative domains. In this paper, we
present the findings of a survey study on people's perceptions of text-to-image
generation. We touch on participants' technical understanding of the emerging
technology, their fears and concerns, and thoughts about risks and dangers of
text-to-image generation to the individual and society. We find that while
participants were aware of the risks and dangers associated with the
technology, only few participants considered the technology to be a personal
risk. The risks for others were more easy to recognize for participants.
Artists were particularly seen at risk. Interestingly, participants who had
tried the technology rated its future importance lower than those who had not
tried it. This result shows that many people are still oblivious of the
potential personal risks of generative artificial intelligence and the
impending societal changes associated with this technology.


  We present a procedure for the design and construction of a passive,
multipole, mechanical high-stop vibration isolator. The isolator, consisting of
a stack of metal disks connected by thin wires, attenuates frequencies in the
kilohertz range, and is suited to both vacuum and cryogenic environments. We
derive an approximate analytical model and compare its predictions for the
frequencies of the normal modes to those of a finite element analysis. The
analytical model is exact for the modes involving only motion along and
rotation about the longitudinal axis, and it gives a good approximate
description of the transverse modes. These results show that the high-frequency
behavior of a multi-stage isolator is well characterized by the natural
frequencies of a single stage. From the single-stage frequency formulae, we
derive relationships among the various geometrical parameters of the isolator
to guarantee equal attenuation in all degrees of freedom. We then derive
expressions for the attenuation attainable with a given isolator length, and
find that the most important limiting factor is the elastic limit of the spring
wire material. For our application, which requires attenuations of 250 dB at 1
kHz, our model specifies a six-stage design using brass disks of approximately
2 cm in both radius and thickness, connected by 3 cm steel wires of diameters
ranging from 25 to 75 microns. We describe the construction of this isolator in
detail, and compare measurements of the natural frequencies of a single stage
with calculations from the analytical model and the finite element package. For
translations along and rotations about the longitudinal axes, all three results
are in agreement to within 10% accuracy.


  Literature about the scholarly impact of scientific research offers very few
contributions on private sector research, and the comparison with public
sector. In this work, we try to fill this gap examining the citation-based
impact of Italian 2010-2017 publications distinguishing authorship by the
private sector from the public sector. In particular, we investigate the
relation between different forms of collaboration and impact: how intra-sector
private publications compare to public, and how private-public joint
publications compare to intra-sector extramural collaborations. Finally, we
assess the different effect of international collaboration on private and
public research impact, and whether there occur differences across research
fields.


  We study antiferromagnetism and single-particle properties in the
two-dimensional half-filled Hubbard model at low temperature. Collective spin
fluctuations are governed by a non-linear sigma model that we derive from the
Hubbard model for any value of the Coulomb repulsion. As the Coulomb repulsion
increases, the ground state progressively evolves from a Slater to a
Mott-Heisenberg antiferromagnet. At finite temperature, we find a
metal-insulator transition between a pseudogap phase at weak coupling and a
Mott-Hubbard insulator at strong coupling.


  At zero temperature, the Landauer formalism combined with static density
functional theory is able to correctly reproduce the Kondo plateau in the
conductance of the Anderson impurity model provided that an
exchange-correlation potential is used which correctly exhibits steps at
integer occupation. Here we extend this recent finding to multi-level quantum
dots described by the constant-interaction model. We derive the exact
exchange-correlation potential in this model for the isolated dot and deduce an
accurate approximation for the case when the dot is weakly coupled to two
leads. We show that at zero temperature and for non-degenerate levels in the
dot we correctly obtain the conductance plateau for any odd number of electrons
on the dot. We also analyze the case when some of the levels of the dot are
degenerate and again obtain good qualitative agreement with results obtained
with alternative methods. As in the case of a single level, for temperatures
larger than the Kondo temperature, the Kohn-Sham conductance fails to reproduce
the typical Coulomb blockade peaks. This is attributed to {\em dynamical}
exchange-correlation corrections to the conductance originating from
time-dependent density functional theory.


  In this paper we study the following stochastic Hamiltonian system in
${\mathbb R}^{2d}$ (a second order stochastic differential equation), $$ d \dot
X_t=b(X_t,\dot X_t)d t+\sigma(X_t,\dot X_t)d W_t,\ \ (X_0,\dot
X_0)=(x,v)\in{\mathbb R}^{2d}, $$ where $b(x,v):{\mathbb R}^{2d}\to{\mathbb
R}^d$ and $\sigma(x,v):{\mathbb R}^{2d}\to{\mathbb R}^d\otimes{\mathbb R}^d$
are two Borel measurable functions. We show that if $\sigma$ is bounded and
uniformly non-degenerate, and $b\in H^{2/3,0}_p$ and $\nabla\sigma\in L^p$ for
some $p>2(2d+1)$, where $H^{\alpha,\beta}_p$ is the Bessel potential space with
differentiability indices $\alpha$ in $x$ and $\beta$ in $v$, then the above
stochastic equation admits a unique strong solution so that $(x,v)\mapsto
Z_t(x,v):=(X_t,\dot X_t)(x,v)$ forms a stochastic homeomorphism flow, and
$(x,v)\mapsto Z_t(x,v)$ is weakly differentiable with
ess.$\sup_{x,v}E\left(\sup_{t\in[0,T]}|\nabla Z_t(x,v)|^q\right)<\infty$ for
all $q\geq 1$ and $T\geq 0$. Moreover, we also show the uniqueness of
probability measure-valued solutions for kinetic Fokker-Planck equations with
rough coefficients by showing the well-posedness of the associated martingale
problem and using the superposition principle established by Figalli \cite{Fi}
and Trevisan \cite{Tre}.


  In this paper the nonequilibrium correction to the distribution function
containing a time and space dependent mass is obtained. Given that, fully
consistent fluid dynamic equations are formulated. Then, the physics of the
bulk viscosity is elaborated for Boltzmann and Bose-Einstein gases within the
relaxation time approximation. It is found that the parametric form of the
ratio $\zeta/\tau_R$ for the quantum gas is affected by the infrared cut-off.
This may be an indication that the relaxation time approximation is too crude
to obtain a reliable form of bulk viscosity.


  For a domain $D\subset {\Bbb{C}}^n$ we construct a continuous foliation of
$D$ into one real dimensional curves such that any function $f\in {C^1(D)}$
which can be extended holomorphically into some neighborhood of each curve in
the foliation will be holomorphic on $D$.


  We investigate the influence of large-scale meridional circulation on solar
p-modes by quasi-degenerate perturbation theory, as proposed by
\cite{lavely92}. As an input flow we use various models of stationary
meridional circulation obeying the continuity equation. This flow perturbs the
eigenmodes of an equilibrium model of the Sun. We derive the signatures of the
meridional circulation in the frequency multiplets of solar p-modes. In most
cases the meridional circulation leads to negative average frequency shifts of
the multiplets. Further possible observable effects are briefly discussed.


  In this paper, we study extensions of graded affine Hecke algebra modules. In
particular, based on an explicit projective resolution on graded affine Hecke
algebra modules, we prove a duality result for Ext-groups. This duality result
with an Ind-Res resolution gives an algebraic proof of the fact that all higher
Ext-groups between discrete series vanish.


  Estimating the probability that a sum of random variables (RVs) exceeds a
given threshold is a well-known challenging problem. Closed-form expression of
the sum distribution is usually intractable and presents an open problem. A
crude Monte Carlo (MC) simulation is the standard technique for the estimation
of this type of probability. However, this approach is computationally
expensive especially when dealing with rare events (i.e events with very small
probabilities). Importance Sampling (IS) is an alternative approach which
effectively improves the computational efficiency of the MC simulation. In this
paper, we develop a general framework based on IS approach for the efficient
estimation of the probability that the sum of independent and not necessarily
identically distributed heavy-tailed RVs exceeds a given threshold. The
proposed IS approach is based on constructing a new sampling distribution by
twisting the hazard rate of the original underlying distribution of each
component in the summation. A minmax approach is carried out for the
determination of the twisting parameter, for any given threshold. Moreover,
using this minmax optimal choice, the estimation of the probability of interest
is shown to be asymptotically optimal as the threshold goes to infinity. We
also offer some selected simulation results illustrating first the efficiency
of the proposed IS approach compared to the naive MC simulation. The
near-optimality of the minmax approach is then numerically analyzed.


  We show that for large integers $n$, whose ratios of consecutive divisors are
bounded above by an arbitrary constant, the number of prime factors follows an
approximate normal distribution, with mean $C \log_2 n$ and variance $V \log_2
n$, where $C=1/(1-e^{-\gamma})\approx 2.280$ and $V\approx 0.414$. This result
is then generalized in two different directions.


  We consider the sparse regression model where the number of parameters $p$ is
larger than the sample size $n$. The difficulty when considering
high-dimensional problems is to propose estimators achieving a good compromise
between statistical and computational performances. The BIC estimator for
instance performs well from the statistical point of view \cite{BTW07} but can
only be computed for values of $p$ of at most a few tens. The Lasso estimator
is solution of a convex minimization problem, hence computable for large value
of $p$. However stringent conditions on the design are required to establish
fast rates of convergence for this estimator. Dalalyan and Tsybakov
\cite{arnak} propose a method achieving a good compromise between the
statistical and computational aspects of the problem. Their estimator can be
computed for reasonably large $p$ and satisfies nice statistical properties
under weak assumptions on the design. However, \cite{arnak} proposes sparsity
oracle inequalities in expectation for the empirical excess risk only. In this
paper, we propose an aggregation procedure similar to that of \cite{arnak} but
with improved statistical performances. Our main theoretical result is a
sparsity oracle inequality in probability for the true excess risk for a
version of exponential weight estimator. We also propose a MCMC method to
compute our estimator for reasonably large values of $p$.


  The anomalous properties of the Hall constant in the normal state of
high-$T_c$ superconductors are investigated within the single-band Hubbard
model. We argue that the Mori theory is the appropriate formalism to address
the Hall constant, since it aims directly at resistivities rather than
conductivities. More specifically, the frequency dependent Hall constant
decomposes into its infinite frequency limit and a memory function
contribution. As a first step, both terms are calculated perturbatively in $U$
and on an infinite dimensional lattice, where $U$ is the correlation strength.
If we allow $U$ to be of the order of twice the bare band width, the memory
function contribution causes the Hall constant to change sign as a function of
doping and to decrease as a function of temperature.


  We address the problem of cyclic termgraph rewriting. We propose a new
framework where rewrite rules are tuples of the form $(L,R,\tau,\sigma)$ such
that $L$ and $R$ are termgraphs representing the left-hand and the right-hand
sides of the rule, $\tau$ is a mapping from the nodes of $L$ to those of $R$
and $\sigma$ is a partial function from nodes of $R$ to nodes of $L$. $\tau$
describes how incident edges of the nodes in $L$ are connected in $R$. $\tau$
is not required to be a graph morphism as in classical algebraic approaches of
graph transformation. The role of $\sigma$ is to indicate the parts of $L$ to
be cloned (copied). Furthermore, we introduce a new notion of \emph{cloning
pushout} and define rewrite steps as cloning pushouts in a given category.
Among the features of the proposed rewrite systems, we quote the ability to
perform local and global redirection of pointers, addition and deletion of
nodes as well as cloning and collapsing substructures.


  In the present work, spontaneous magnetization is observed in the inverse
magnetic susceptibility of La$_{0.7}$Ca$_{0.3}$MnO$_3$ and
La$_{0.7}$Ba$_{0.3}$MnO$_3$ compounds above $T_C$ up to a temperature $T^*$.
From information gathered from neutron diffraction, dilatometry, and high-field
magnetization data, we suggest that $T^*$ is related to the transition
temperature of the low-temperature (high magnetic field) magnetic phase. In the
temperature region between $T^*$ and $T_C$, the application of a magnetic field
drives the system from the high-temperature to low-temperature magnetic phases,
the latter possessing a higher magnetization.


  We prove that the entangling capacity of a two-qubit unitary operator without
local ancillas, both with and without the restriction to initial product
states, as quantified by the maximum attainable concurrence, is directly
related to the distinguishability of a closely related pair of two-qubit
unitary operators. These operators are the original operator transformed into
its canonical form and the adjoint of this canonical form. The
distinguishability of these operators is quantified by the minimum overlap of
the output states over all possible input probe states. The entangling capacity
of the original unitary operator is therefore directly related to the degree of
non-Hermiticity of its canonical form, as quantified in an operationally
satisfactory manner in terms of the extent to which it can be distinguished, by
measurement, from its adjoint. Furthermore, the maximum entropy of
entanglement, again without local ancillas, that a given two-qubit unitary
operator can generate, is found to be closely related to the classical
capacities of certain quantum channels.


  Federated Learning (FL) is a Machine Learning (ML) technique that aims to
reduce the threats to user data privacy. Training is done using the raw data on
the users' device, called clients, and only the training results, called
gradients, are sent to the server to be aggregated and generate an updated
model. However, we cannot assume that the server can be trusted with private
information, such as metadata related to the owner or source of the data. So,
hiding the client information from the server helps reduce privacy-related
attacks. Therefore, the privacy of the client's identity, along with the
privacy of the client's data, is necessary to make such attacks more difficult.
This paper proposes an efficient and privacy-preserving protocol for FL based
on group signature. A new group signature for federated learning, called GSFL,
is designed to not only protect the privacy of the client's data and identity
but also significantly reduce the computation and communication costs
considering the iterative process of federated learning. We show that GSFL
outperforms existing approaches in terms of computation, communication, and
signaling costs. Also, we show that the proposed protocol can handle various
security attacks in the federated learning environment.


  It has been recently reported that ultraviolet harmonic vortices can be
produced when a high-power circular-polarized laser pulse travels through a
micro-scale waveguide. However, the harmonic generation quenches typically
after a few tens of microns of propagation, due to the build-up of
electrostatic potential that suppresses the amplitude of the surface wave. Here
we propose to utilize a hollow-cone channel to overcome this obstacle. When
traveling in a cone target, the laser intensity gradually increases, allowing
the surface wave to maintain a high amplitude for a much longer distance. The
harmonic vortices can be produced with very high efficiency. According to
three-dimensional particle-in-cell simulations, the overall efficiency are
boosted by almost one order of magnitude, reaching $>20\%$. It is also found
that using the cone targets can mitigate efficiency decline due to pre-heating
of plasma by laser prepulse. The proposed scheme paves the way to the
development of powerful optical vortices sources in the extreme ultraviolet
regime - an area of significant fundamental and applied physics potential.


  The Orion cloud complex presents a variety of star formation mechanisms and
properties and it is still one of the most intriguing targets for star
formation studies. We present VISTA/VIRCAM near-infrared observations of the
L1630N star forming region, including the stellar clusters NGC 2068 and NGC
2071, in the Orion molecular cloud B and discuss them in combination with
Spitzer data. We select 186 young stellar object (YSO) candidates in the region
on the basis of multi-colour criteria, confirm the YSO nature of the majority
of them using published spectroscopy from the literature, and use this sample
to investigate the overall star formation properties in L1630N. The K-band
luminosity function of L1630N is remarkably similar to that of the Trapezium
cluster, i.e., it presents a broad peak in the range 0.3-0.7 M$_\odot$ and a
fraction of sub-stellar objects of $\sim$20%. The fraction of YSOs still
surrounded by disk/envelopes is very high ($\sim$85%) compared to other star
forming regions of similar age (1-2 Myr), but includes some uncertain
corrections for diskless YSOs. Yet, a possibly high disk fraction together with
the fact that 1/3 of the cloud mass has a gas surface density above the
threshold for star formation ($\sim$129 M$_\odot$ pc$^{-2}$), points towards a
still on-going star formation activity in L1630N. The star formation efficiency
(SFE), star formation rate (SFR) and density of star formation of L1630N are
within the ranges estimated for galactic star forming regions by the Spitzer
"core to disk" and "Gould's Belt" surveys. However, the SFE and SFR are lower
than the average value measured in the Orion A cloud and, in particular, lower
than that in the southern regions of L1630. This might suggest different star
formation mechanisms within the L1630 cloud complex.


  To make the best use of the underlying structure of faces, the collective
information through face datasets and the intermediate estimates during the
upsampling process, here we introduce a fully convolutional multi-stage neural
network for 4$\times$ super-resolution for face images. We implicitly impose
facial component-wise attention maps using a segmentation network to allow our
network to focus on face-inherent patterns. Each stage of our network is
composed of a stem layer, a residual backbone, and spatial upsampling layers.
We recurrently apply stages to reconstruct an intermediate image, and then
reuse its space-to-depth converted versions to bootstrap and enhance image
quality progressively. Our experiments show that our face super-resolution
method achieves quantitatively superior and perceptually pleasing results in
comparison to state of the art.


  We consider the geometric evolution problem of entire graphs moving by
fractional mean curvature. For this, we study the associated nonlocal
quasilinear evolution equation satisfied by the family of graph functions. We
establish, using an analytic semigroup approach, short time existence,
uniqueness and optimal H\"older regularity in time and space of classical
solutions of the nonlocal equation, depending on the regularity of the initial
graph. The method also yields $C^\infty-$smoothness estimates of the evolving
graphs for positive times.


  We derive a simple relational expression between the spin polarization ratio
of resistivity, $P_\rho$, and the anisotropic magnetoresistance ratio $\Delta
\rho/\rho$, and that between the spin polarization ratio of the density of
states at the Fermi energy, $P_{\rm DOS}$, and $\Delta \rho/\rho$ for nearly
half-metallic ferromagnets. We find that $P_\rho$ and $P_{\rm DOS}$ increase
with increasing $|\Delta \rho/\rho|$ from 0 to a maximum value. In addition, we
roughly estimate $P_\rho$ and $P_{\rm DOS}$ for a Co$_2$FeGa$_{0.5}$Ge$_{0.5}$
Heusler alloy by substituting its experimentally observed $\Delta \rho/\rho$
into the respective expressions.


  The distributions of solar flare energies and waiting times have not been
described simultaneously by a single physical model, yet. In this research, we
investigate whether recent avalanche models can describe the distributions for
both the released energies and waiting times of flares in an active region.
Flaring events are simulated using the modified Lu and Hamilton model (Lu and
Hamilton (1991), ApJ, 380, 89) and also the optimized model (Farhang et al.
(2018), ApJ, 859, 41). Applying a probability balance equation approach, we
study the statistics of the simulated flaring events and investigate the origin
of the observed power law in the flare frequency-size distribution. The results
indicate that the power law originates in the distribution of transition rates
(the distribution of the probabilities of transitions between different
energies) rather than the distribution of the energy of the active region. It
is also observed that the waiting-time distribution of simulated flaring events
follows a q-exponential function which approximates a simple Poisson
distribution.


  We study correlation functions in an equilibrated spatially modulated phase
of Einstein-Maxwell two-derivative gravity. We find that the ratio of the
appropriate low frequency limit of the stress-stress two point function to the
entropy density is modulated. The conductivity, the stress-current and
current-stress correlation functions are also modulated. At temperatures close
to the phase transition we obtain analytic expressions for some of the
correlation functions.


  With the LHC discovery of a 125 GeV Higgs-like boson, we study gravitational
interaction of the Higgs boson via the unique dimension-4 operator involving
Higgs doublet and scalar curvature, $\,\xi H^\dag H R\,$, with nonminimal
coupling $\,\xi\,$. This Higgs portal term can be transformed away in Einstein
frame and induces gauge-invariant effective interactions in the Higgs sector.
We study the weak boson scattering in Einstein frame, and explicitly
demonstrate the longitudinal-Goldstone boson equivalence theorem in the
presence of $\,\xi\,$ coupling. With these, we derive unitarity bound on the
Higgs gravitational coupling $\,\xi\,$ in Einstein frame, which is stronger
than that inferred from the current LHC Higgs measurements. We further study
$\xi$-dependent weak boson scattering cross sections at TeV scale, and propose
a new LHC probe of the Higgs-gravity coupling $\,\xi\,$ via weak boson
scattering experiments.


  The Casimir interaction and torque are related phenomena originating from the
exchange of electromagnetic excitations between objects. While the Casimir
force exists between any types of objects, the materials or geometrical
anisotropy drives the emergence of the Casimir torque. Here both phenomena are
studied theoretically between dielectric films with immersed parallel single
wall carbon nanotubes in the dilute limit with their chirality and collective
electronic and optical response properties taken into account. It is found that
the Casimir interaction is dominated by thermal fluctuations at sub-micron
separations, while the torque is primarily determined by quantum mechanical
effects. This peculiar quantum vs. thermal separation is attributed to the
strong influence of reduced dimensionality and inherent anisotropy of the
materials. Our study suggests that nanostructured anisotropic materials can
serve as novel platforms to uncover new functionalities in ubiquitous Casimir
phenomena.


  In the background of a gravitational collapse, we compute the transition
amplitudes for the creation of particles for distant observers due to
higher-derivative interactions in addition to Hawking radiation. The amplitudes
grow exponentially with time and become of order 1 when the collapsing matter
is about a Planck length outside the horizon. As a result, the effective theory
breaks down at the scrambling time, invalidating its prediction of Hawking
radiation. Planckian physics comes into play to decide the fate of black-hole
evaporation.


  Generalizing de Vries Compactification Theorem and strengthening Leader Local
Compactification Theorem, we describe the partially ordered set $(\LL(X),\le)$
of all (up to equivalence) locally compact Hausdorff extensions of a Tychonoff
space $X$. Using this description, we find the necessary and sufficient
conditions which has to satisfy a map between two Tychonoff spaces in order to
have some kind of extension over arbitrary given in advance Hausdorff local
compactifications of these spaces; we regard the following kinds of extensions:
open, quasi-open, skeletal, perfect, injective, surjective. In this way we
generalize some results of V. Z. Poljakov.


  This paper proposes a novel approach for relation extraction from free text
which is trained to jointly use information from the text and from existing
knowledge. Our model is based on two scoring functions that operate by learning
low-dimensional embeddings of words and of entities and relationships from a
knowledge base. We empirically show on New York Times articles aligned with
Freebase relations that our approach is able to efficiently use the extra
information provided by a large subset of Freebase data (4M entities, 23k
relationships) to improve over existing methods that rely on text features
alone.


  Generators of Markov processes on a countable state space can be represented
as finite or infinite matrices. One key property is that the off-diagonal
entries corresponding to jump rates of the Markov process are non-negative.
Here we present stochastic characterizations of the semigroup generated by a
generator with possibly negative rates. This is done by considering a larger
state space with one or more particles and antiparticles, with antiparticles
being particles carrying a negative sign.


  This paper is a case study of horizontal atmospheric rolls that formed over
the Black Sea on 16 August 2007. The rolls were discovered in WRF modeling
results for a mesoscale cyclone that originated over the sea on 15 August 2007.
The roll formation mechanisms, such as Rayleigh-Benard convective instability,
dynamic instability, advection and stretching of vertical velocity field
inhomogeneities, are considered. It is shown that indeed convective instability
played an important role in the roll formation but dynamic instability did not
occur. In order to distinguish other possible mechanisms of the roll formation
numerical experiments were performed. In these experiments sea surface
temperature in the initial conditions was decreased in order to prevent
convective instability. Even though convective instability was suppressed
roll-like structures still appeared in the modeling results, although their
height and circulation velocity were smaller than in the control run. It was
found that these structures were caused by advection and stretching of vertical
velocity field inhomogeneities (i.e. small areas of strong updrafts or
downdrafts).


  The lattice of laser-electron storage ring with controlled momentum
compaction factor dedicated to generation of intense X-rays under Compton
scattering is described. In such storage ring one can achieve the large energy
acceptance and keep the long-term stable motion of electron beam with large
energy spread. The intensity of X-rays may be very stable due to using of
electron beam with steady-state parameters for Compton scattering. Parameters
of the storage ring, electron beam and X-rays obtained by electron beam
dynamics simulation involving Compton scattering are presented.


  We propose the holdout randomization test (HRT), an approach to feature
selection using black box predictive models. The HRT is a specialized version
of the conditional randomization test (CRT; Candes et al., 2018) that uses data
splitting for feasible computation. The HRT works with any predictive model and
produces a valid $p$-value for each feature. To make the HRT more practical, we
propose a set of extensions to maximize power and speed up computation. In
simulations, these extensions lead to greater power than a competing
knockoffs-based approach, without sacrificing control of the error rate. We
apply the HRT to two case studies from the scientific literature where
heuristics were originally used to select important features for predictive
models. The results illustrate how such heuristics can be misleading relative
to principled methods like the HRT. Code is available at
https://github.com/tansey/hrt.


  Dark photon dark matter may be produced by the cosmic strings in association
with the dark U(1) gauge symmetry breaking. We perform three-dimensional
lattice simulations of the Abelian-Higgs model and follow the evolution of
cosmic strings. In particular, we simulate the case of (very) light vector
boson and find that such vector bosons are efficiently produced by the collapse
of small loops while the production is inefficient in the case of heavy vector
boson. We calculate the spectrum of the gravitational wave background produced
by the cosmic string loops for the light vector boson case and find
characteristic features in the spectrum, which can serve as a probe of the dark
photon dark matter scenario. In particular, we find that the current
ground-based detectors may be sensitive to such gravitational wave signals and
also on-going/future pulsar timing observations give stringent constraint on
the dark photon dark matter scenario.


  The contribution of instanton-induced effective inter-quark interactions to
the baryon mass splittings was considered in the bag model. It is found that
results are different from those obtained in the constituent quark model where
the instanton effects are like those from one-gluon exchange. This is because
in the context of the bag model calculation the one-body instanton-induced
interaction has to be included.


  Using a large sample of bright nearby stars with accurate Gaia Data Release 2
astrometry and auxiliary spectroscopy we map out the properties of the
principle Galactic components such as the "thin" and "thick" discs and the
halo. We show that in the Solar neighborhood, there exists a large population
of metal-rich ([Fe/H]>-0.7) stars on highly eccentric orbits. By studying the
evolution of elemental abundances, kinematics and stellar ages in the plane of
azimuthal velocity v_phi and metallicity [Fe/H], we demonstrate that this
metal-rich halo-like component, which we dub the Splash, is linked to the
alpha-rich (or "thick") disc. Splash stars have little to no angular momentum
and many are on retrograde orbits. They are predominantly old, but not as old
as the stars deposited into the Milky Way in the last major merger. We argue,
in agreement with several recent studies, that the Splash stars may have been
born in the Milky Way's proto-disc prior to the massive ancient accretion event
which drastically altered their orbits. We can not, however, rule out other
(alternative) formation channels. Taking advantage of the causal connection
between the merger and the Splash, we put constraints of the epoch of the last
massive accretion event to have finished 9.5 Gyr ago. The link between the
local metal-rich and metal-poor retrograde stars is confirmed using a large
suite of cutting-edge numerical simulations of the Milky Way's formation.


  We have studied numerically the Lee-Yang singularities of the four
dimensional Ising model at criticality, which is believed to be in the same
universality class as the $\phi_4^4$ scalar field theory. We have focused in
the numerical characterization of the logarithmic corrections to the scaling of
the zeros of the partition function and its cumulative probability
distribution, finding a very good agreement with the predictions of the
renormalization group computation on the $\phi_4^4$ scalar field theory. We
have found that this agreement improves much more with the order of the
Lee-Yang zeros. To obtain these results, we have extended a previous study [R.
Kenna and C. B. Lang, Nucl. Phys. {\bf B393} 461 (1993)] in which were computed
numerically the first two zeros for $L\le 24$ lattices, to the computation of
the first four zeros for $L\le 64$ lattices.


  Short millimeter observations of radio-loud AGN offer the opportunity to
study the physics of their inner relativistic jets, from where the bulk
millimeter emission is radiated. Millimeter jets are significantly less
affected by Faraday rotation and depolarization than in radio. Also, the
millimeter emission is dominated by the innermost jet regions, that are
invisible in radio owing to synchrotron opacity. We present the first dual
frequency simultaneous 86GHz and 229GHz polarimetric survey of all four Stokes
parameters of a large sample of 211 radio loud active galactic nuclei, designed
to be flux limited at 1Jy at 86GHz. The observations were most of them made in
mid August 2010 using the XPOL polarimeter on the IRAM 30 m millimeter radio
telescope. Linear polarization detections above 3 sigma median level of ~1.0%
are reported for 183 sources at 86GHz, and for 23 sources at 229GHz, where the
median 3 sigma level is ~6.0%. We show a clear excess of the linear
polarization degree detected at 229GHz with regard to that at 86GHz by a factor
of ~1.6, thus implying a progressively better ordered magnetic field for blazar
jet regions located progressively upstream in the jet. We show that the linear
polarization angle, both at 86 and 229GHz, and the jet structural position
angle for both quasars and BL Lacs do not show a clear preference to align in
either parallel or perpendicular directions. Our variability study with regard
to the 86GHz data from our previous survey points out a large degree variation
of total flux and linear polarization in time scales of years by median factors
of ~1.5 in total flux, and ~1.7 in linear polarization degree -maximum
variations by factors up to 6.3, and ~5, respectively-, with 86% of sources
showing linear polarization angles evenly distributed with regard to our
previous measurements.


  We report a remarkable universality in the patterns of violence arising in
three high-profile ongoing wars, and in global terrorism. Our results suggest
that these quite different conflict arenas currently feature a common type of
enemy, i.e. the various insurgent forces are beginning to operate in a similar
way regardless of their underlying ideologies, motivations and the terrain in
which they operate. We provide a microscopic theory to explain our main
observations. This theory treats the insurgent force as a generic,
self-organizing system which is dynamically evolving through the continual
coalescence and fragmentation of its constituent groups.


  We introduce an efficient Langevin method to study bilinear Fermionic
Hamiltonians interacting with classical fields. Our method is suitable for very
large systems and offers high accuracy. To demonstrate the method, we study
complex non-coplanar chiral spin textures on the triangular Kondo lattice
model. We also explore non-equilibrium mesoscale physics such as chiral domain
coarsening and Z2 vortex annihilation.


  This article reviews three related topics: the extragalactic background l
ight and its sources, evolution models for the dust absorption and emission in
galaxies, and empirical constraints on these transfer pr ocesses in nearby
starburst galaxies. It is intended that the material presented here will serve
as an introduction to this Joint Discussion.


  We classify the necessary and sufficient conditions to obtain the
near-horizon geometry of extremal supersymmetric rotating black holes embedded
in 11d supergravity. Such rotating black holes admit an AdS$_2$ near-horizon
geometry which is fibered by the transverse spacetime directions. Despite their
clear interest to understanding the entropy of rotating black holes, these
solutions have evaded all previous supersymmetric classification programs due
to the non-trivial fibration structure. In this paper we allow for the most
general fibration over AdS$_2$ with a flux configuration permitting rotating
M2-branes. Using G-structure techniques we rewrite the conditions for
supersymmetry in terms of differential equations on an eight-dimensional
balanced space. The 9d compact internal space is a U$(1)$-fibration over this
8d base. The geometry is constrained by a master equation reminiscent of the
one found in the non-rotating case. We give a Lagrangian from which the
equations of motion may be derived, and show how the asymptotically AdS$_4$
electrically charged Kerr-Newman black hole in 4d $\mathcal{N}=2$ supergravity
is embedded in the classification. In addition, we present the conditions for
the near-horizon geometry of rotating black strings in Type IIB by using
dualities with the 11d setup.


  Kawamata proposed a conjecture predicting that every nef and big line bundle
on a smooth projective variety with trivial first Chern class has nontrivial
global sections. We verify this conjecture for several cases, including (i) all
hyperk\"{a}hler varieties of dimension $\leq 6$; (ii) all known hyperk\"{a}hler
varieties except for O'Grady's 10-dimensional example; (iii) general complete
intersection Calabi-Yau varieties in certain Fano manifolds (e.g. toric ones).
Moreover, we investigate the effectivity of Todd classes of hyperk\"{a}hler
varieties and Calabi-Yau varieties. We prove that the fourth Todd classes are
"fakely effective" for all hyperk\"{a}hler varieties and general complete
intersection Calabi-Yau varieties in products of projective spaces.


  A search engine maintains local copies of different web pages to provide
quick search results. This local cache is kept up-to-date by a web crawler that
frequently visits these different pages to track changes in them. Ideally, the
local copy should be updated as soon as a page changes on the web. However,
finite bandwidth availability and server restrictions limit how frequently
different pages can be crawled. This brings forth the following optimization
problem: maximize the freshness of the local cache subject to the crawling
frequencies being within prescribed bounds. While tractable algorithms do exist
to solve this problem, these either assume the knowledge of exact page change
rates or use inefficient methods such as MLE for estimating the same. We
address this issue here.
  We provide three novel schemes for online estimation of page change rates,
all of which have extremely low running times per iteration. The first is based
on the law of large numbers and the second on stochastic approximation. The
third is an extension of the second and includes a heavy-ball momentum term.
All these schemes only need partial information about the page change process,
i.e., they only need to know if the page has changed or not since the last
crawled instance. Our main theoretical results concern asymptotic convergence
and convergence rates of these three schemes. In fact, our work is the first to
show convergence of the original stochastic heavy-ball method when neither the
gradient nor the noise variance is uniformly bounded. We also provide some
numerical experiments (based on real and synthetic data) to demonstrate the
superiority of our proposed estimators over existing ones such as MLE. We
emphasize that our algorithms are also readily applicable to the
synchronization of databases and network inventory management.


  We discuss total cross-sections within the context of the QCD calculable
mini-jet model, highlighting its successes and failures. In particular we show
its description of $\gamma \gamma \to hadrons$ and compare it with OPAL and L3
data. We extrapolate this result to $\gamma p$ total cross-sections and propose
a phenomenological ans\"atz for virtual photon cross-sections. We point out
that the good agreement with data obtained with the Eikonal Minijet Model
should not hide the many uncertainties buried in the impact parameter
distribution. A model obtained from Soft Gluon Summation is briefly discussed
and its application to hadronic cross-sections is shown.


  Many argued (Accardi and Fedullo, Pitowsky) that Kolmogorov's axioms of
classical probability theory are incompatible with quantum probabilities, and
this is the reason for the violation of Bell's inequalities. Szab\'o showed
that, in fact, these inequalities are not violated by the experimentally
observed frequencies if we consider the real, ``effective'' frequencies. We
prove in this work a theorem which generalizes this result: ``effective''
frequencies associated to quantum events always admit a Kolmogorovian
representation, when these events are collected through different experimental
set ups, the choice of which obeys a classical distribution.


  We study the expected properties of starbursts in order to provide the point
of reference for interpretation of high-z galaxy surveys and of very metal-poor
galaxies. We concentrate mainly on the UV characteristics such as the ionizing
spectra, the UV continuum, the Ly alpha and HeII 1640 A line and two-photon
continuum emission. We use evolutionary synthesis models covering metallicities
from Pop III to solar and a wide range of IMFs. We also combine the synthetic
SEDs with the CLOUDY photoionization code for more accurate predictions of
nebular emission, and to study possible departures from case B assumed in the
synthesis models. The ionizing fluxes, UV continuum properties, and predicted
Ly alpha and HeII 1640 A line strengths are presented for synthesis models
covering a wider range of parameter space than our earlier calculations. Strong
departures from case B predictions are obtained for Ly alpha and two-photon
continuum at low metallicities. At low nebular densities both are shown to be
enhanced proportionally to the mean energy carried by the Lyman continuum
photons emitted by the ionizing source. Larger Ly alpha equivalent widths are
therefore predicted at low metallicity. The HeII 1640 A line can be weaker than
case B predicts (in terms of flux as well as the equivalent width) due to its
ionization parameter dependence and to the enhanced underlying two-photon
continuum. Our results have implications for the interpretation of star-forming
metal-poor and/or high redshift galaxies, for galaxies among the Ly alpha
emitters (LAE) and Lyman Break galaxy (LBG) populations, and for searches of
Population III stars in the distant Universe.


  It is often stated that if one is presented with a snapshot of the positions
of the molecules of a glass and one of a liquid, one is unable to tell the
difference. Here we argue instead that given several such snapshots taken over
a time-interval, even without specifying the times, there is a definite
procedure to assess precisely the level of glassiness: it suffices to
concatenate the snapshots side-by-side, and to subject the joint picture to a
lossless compression protocol. We argue that the size of the compressed file
yields a direct and unambiguous measure of the `vibrational' and
`configurational' entropies, and may be used to study the associated glass
length scale in or out of equilibrium through the size and frequency of the
repeated motifs essential to the compression, a quantity that would diverge at
a putative glass transition.


  We prove that every quasitoric manifold admits an invariant metric of
positive scalar curvature.


  If quenched fast enough, a liquid is able to avoid crystallization and will
remain in a metastable supercooled state down to the glass transition, with an
important increase in viscosity upon further cooling. There are important
differences in the way liquids relax as they approach the glass transition,
rapid or slow variation in dynamic quantities under moderate temperature
changes, and a simple means to quantify such variations is provided by the
concept of "fragility". Here, we report molecular dynamics simulations of a
typical network-forming glass, Ge-Se, and find that the relaxation behaviour of
the supercooled liquid is strongly correlated to the variation of rigidity with
temperature and the spatial distribution of the corresponding topological
constraints which, ultimately connect to fragility minima. This permits
extending the fragility concept to aspects of topology/rigidity, and to the
degree of homogeneity of the atomic-sale interactions for a variety of
structural glasses.


  We present a scheme well-suited to investigate quantitatively the angular
momentum coherence of molecular fragments. Assuming that the dissociated
molecule has a null total angular momentum, we investigate the propagation of
the corresponding atomic fragments in the apparatus. We show that the
envisioned interferometer enables one to distinguish unambiguously a
spin-coherent from a spin-incoherent dissociation, as well as to estimate the
purity of the angular momentum density matrix associated with the fragments.
This setup, which may be seen as an atomic analogue of a twin-photon
interferometer, can be used to investigate the suitability of molecule
dissociation processes -- such as the metastable hydrogen atoms H($2^2
S$)-H($2^2 S$) dissociation - for coherent twin-atom optics.


  For positive integers $s$, $t$, $m$ and $n$, the Zarankiewicz number
$Z_{s,t}(m,n)$ is defined to be the maximum number of edges in a bipartite
graph with parts of sizes $m$ and $n$ that has no complete biparitite subgraph
containing $s$ vertices in the part of size $m$ and $t$ vertices in the part of
size $n$. A simple argument shows that, for each $t \geq 2$,
$Z_{2,t}(m,n)=(t-1)\binom{m}{2}+n$ when $n \geq (t-1)\binom{m}{2}$. Here, for
large $m$, we determine the exact value of $Z_{2,t}(m,n)$ in almost all of the
remaining cases where $n=\Theta(tm^2)$. We establish a new family of upper
bounds on $Z_{2,t}(m,n)$ which complement a family already obtained by Roman.
We then prove that the floor of the best of these bounds is almost always
achieved. We also show that there are cases in which this floor cannot be
achieved and others in which determining whether it is achieved is likely a
very hard problem. Our results are proved by viewing the problem through the
lens of linear hypergraphs and our constructions make use of existing results
on edge decompositions of dense graphs.


  We study an old geometric optimization problem in the plane. Given a perfect
matching $M$ on a set of $n$ points in the plane, we can transform it to a
non-crossing perfect matching by a finite sequence of flip operations. The flip
operation removes two crossing edges from $M$ and adds two non-crossing edges.
Let $f(M)$ and $F(M)$ denote the minimum and maximum lengths of a flip sequence
on $M$, respectively. It has been proved by Bonnet and Miltzow (2016) that
$f(M)=O(n^2)$ and by van Leeuwen and Schoone (1980) that $F(M)=O(n^3)$. We
prove that $f(M)=O(n\Delta)$ where $\Delta$ is the spread of the point set,
which is defined as the ratio between the longest and the shortest pairwise
distances. This improves the previous bound if the point set has sublinear
spread. For a matching $M$ on $n$ points in convex position we prove that
$f(M)=n/2-1$ and $F(M)={{n/2} \choose 2}$; these bounds are tight.
  Any bound on $F(\cdot)$ carries over to the bichromatic setting, while this
is not necessarily true for $f(\cdot)$. Let $M'$ be a bichromatic matching. The
best known upper bound for $f(M')$ is the same as for $F(M')$, which is
essentially $O(n^3)$. We prove that $f(M')\le n-2$ for points in convex
position, and $f(M')= O(n^2)$ for semi-collinear points.
  The flip operation can also be defined on spanning trees. For a spanning tree
$T$ on a convex point set we show that $f(T)=O(n\log n)$.


  We derive ground state wave functions of superconducting instabilities on the
honeycomb lattice induced by nearest-neighbor attractive interactions. They
reflect the Dirac nature of electrons in the low-energy limit. For the order
parameter that is the same irrespective of the direction to any of the nearest
neighbors we find weak pairing (slowly decaying) behavior in the orbital part
of the Cooper pair with no angular dependence. At the neutrality point, in the
spin-singlet case, we recover a strong pairing behavior. We also derive ground
state wave functions for the superconductivity on the bilayer honeycomb
lattice, with strong interlayer coupling, induced by attractive interactions
between sites that participate in a low-energy description. Without these
interactions, free electrons are described by a Dirac equation with a quadratic
dispersion. This unusual feature, similarly to $^3$He - B phase, leads to the
description with two kinds of Cooper pairs, with $p_x + i p_y$ and $p_x - i
p_y$ pairing, in the presence of the attractive interactions. We discuss the
edge modes of such a spin-singlet superconductor and find that it represents a
trivial topological superconductor.


  We search for an evidence of eta-mesic 4He with the WASA-at-COSY detector.
Two dedicated experiments were performed at the Cooler Synchrotron
COSY-Juelich. The experimental method is based on the measurement of the
excitation functions for the two reaction channels: dd-->3Heppi- and
dd-->3Henpi0, where the outgoing N-pi pairs originate from the conversion of
the eta meson on a nucleon inside the He nucleus. In this contribution, the
experimental method is shortly described and preliminary excitation functions
from the 2010 data are presented.


  (Abridged) Noise considerations for experiments that aim to statistically
estimate the 21 cm signal from high redshift neutral hydrogen during the Epoch
of Reionisation (EoR) using interferometric data are typically computed
assuming a tracked observation, where the telescope pointing centre and
instrument phase centre are the same over the observation. Current low
frequency interferometers use aperture arrays of fixed dipoles, which are
steered electronically on the sky, and have different properties to
mechanically-steered single apertures, such as reduced sensitivity away from
zenith, and discrete pointing positions on the sky. Use of two additional
observing modes is encouraged: (1) zenith drift, where the pointing centre
remains fixed at the zenith, and the phase centre tracks the sky, and (2)
drift+shift, where the telescope uses discrete pointing centres, and the sky
drifts during each pointing. The coherence of measurements in these modes
dictates the optimal reduction in thermal noise by combination of coherent
modes, and the reduction in cosmic variance by combination of incoherent modes
(views of different patches of the sky). The balance between these noise
components provides one measure for the utility of these three modes for
measuring a statistical EoR signature. We provide a general framework for
estimating the uncertainty in the power spectrum for a given observing mode,
telescope beam shape, and antenna distribution. We apply this framework to the
Murchison Widefield Array (MWA) using an analysis of the 2D and 1D power
spectra for 900 hours of observing. We demonstrate that zenith drift scans can
yield marginally lower uncertainty in the signal power compared with tracked
scans for the MWA EoR experiment.


  In this paper, we deal with a class of semilinear elliptic equation in a
bounded domain $\Omega\subset\mathbb{R}^N$, $N\geq 3$, with $C\sp{1,1}$
boundary. Using a new fixed point result of the Krasnoselskii's type for the
sum of two operators, an existence principle of strong solutions is proved. We
give two examples where the nonlinearity can be critical.


  The Sun cubE onE (SEE) is a 12U CubeSat mission proposed for a phase A/B
study to the Italian Space Agency that will investigate Gamma and X-ray fluxes
and ultraviolet (UV) solar emission to support studies in Sun-Earth interaction
and Space Weather from LEO. More in detail, SEE's primary goals are to measure
the flares emission from soft-X to Gamma ray energy range and to monitor the
solar activity in the Fraunhofer Mg II doublet at 280 nm, taking advantage of a
full disk imager payload. The Gamma and X-ray fluxes will be studied with
unprecedented temporal resolution and with a multi-wavelength approach thanks
to the combined use of silicon photodiode and silicon photomultiplier (SiPM)
-based detectors. The flare spectrum will be explored from the keV to the MeV
range of energies by the same payload, and with a cadence up to 10 kHz and with
single-photon detection capabilities to unveil the sources of the solar flares.
The energy range covers the same bands used by GOES satellites, which are the
standard bands for flare magnitude definition. At the same time SiPM detectors
combined with scintillators allow to cover the non-thermal bremsstrahlung
emission in the gamma energy range. Given its UV imaging capabilities, SEE will
be a key space asset to support detailed studies on solar activity, especially
in relation to ultraviolet radiation which strongly interacts with the upper
layers of the Earth's atmosphere, and in relation to space safety, included in
the field of human space exploration. The main goal for the UV payload is to
study the evolution of the solar UV emission in the Mg II band at two different
time scales: yearly variations along the solar cycle and transient variations
during flare events.


  QED based on $\theta$-unexpanded noncomutative space-time in contrast with
the noncommutative QED based on $\theta$-expanded U(1) gauge theory via the
Seiberg-Witten map, is one-loop renormalizable. Meanwhile it suffers from
asymptotic freedom that is not in agreement with the experiment. We show that
QED part of $U_\star(3)\times U_\star(1)$ gauge group as an appropriate gauge
group for the noncommutative QED+QCD, is not only one-loop renormalizable but
also has a $\beta$ function that can be positive, negative and even zero. In
fact the $\beta$ function depends on the mixing parameter $\delta_{13}$ as a
free parameter and it will be equal to its counterpart in the ordinary QED for
$\delta_{13}=0.367\pi$.


  Molecular traits, such as gene expression levels or protein binding
affinities, are increasingly accessible to quantitative measurement by modern
high-throughput techniques. Such traits measure molecular functions and, from
an evolutionary point of view, are important as targets of natural selection.
We review recent developments in evolutionary theory and experiments that are
expected to become building blocks of a quantitative genetics of molecular
traits. We focus on universal evolutionary characteristics: these are largely
independent of a trait's genetic basis, which is often at least partially
unknown. We show that universal measurements can be used to infer selection on
a quantitative trait, which determines its evolutionary mode of conservation or
adaptation. Furthermore, universality is closely linked to predictability of
trait evolution across lineages. We argue that universal trait statistics
extends over a range of cellular scales and opens new avenues of quantitative
evolutionary systems biology.


  We explore the possibility that the fundamental theory of nature does not
contain any scale. This implies a renormalizable quantum gravity theory where
the graviton kinetic term has 4 derivatives, and can be reinterpreted as
gravity minus an anti-graviton. We compute the super-Planckian RGE of
adimensional gravity coupled to a generic matter sector. The Planck scale and a
flat space can arise dynamically at quantum level provided that a quartic
scalar coupling and its $\beta$ function vanish at the Planck scale. This is
how the Higgs boson behaves for $M_h\approx 125$ GeV at $M_t\approx 171$ GeV.
Within agravity, inflation is a generic phenomenon: the slow-roll parameters
are given by the $\beta$-functions of the theory, and are small if couplings
are perturbative. The predictions $n_s\approx 0.967$ and $r\approx 0.13$ arise
if the inflaton is identified with the Higgs of gravity. Furthermore,
quadratically divergent corrections to the Higgs mass vanish: a small weak
scale is natural and can be generated by agravity quantum corrections.


  A model was constructed to explain the orbit modulation of PSR J0737-3039B
(referred to as B), which included the following suppositions: (1) B has
arrived at the aged period and generally cannot emit observable light; (2) The
PSR J0737-3039A (referred to as A) is dynamic and is encircled by dense charged
particles. When A revolves along its orbit, some of the particles are scattered
and form a particle cloud band along its orbit; (3) When passing the two
intersection points of the orbits, B goes through the cloud band and drives the
cloud particles to emit light; (4) Generally, B passes twice through the cloud
band every orbit cycle; hence, there are two bright phases along the orbit. (5)
It is the complexities of the distribution of the cloud particles and B's
emission region that cause the bright phases to drift away from the orbit
intersections. We also provide two predictions for the coming performance of B
to test our model.


  Large pretrained language models generate fluent text but are notoriously
hard to controllably sample from. In this work, we study constrained sampling
from such language models: generating text that satisfies user-defined
constraints, while maintaining fluency and the model's performance in a
downstream task. We propose MuCoLa -- a sampling procedure that combines the
log-likelihood of the language model with arbitrary (differentiable)
constraints in a single energy function, and then generates samples in a
non-autoregressive manner. Specifically, it initializes the entire output
sequence with noise and follows a Markov chain defined by Langevin Dynamics
using the gradients of the energy function. We evaluate MuCoLa on text
generation with soft and hard constraints as well as their combinations
obtaining significant improvements over competitive baselines for toxicity
avoidance, sentiment control, and keyword-guided generation.


  Infrared divergences of QCD scattering amplitudes can be derived from an
anomalous dimension matrix, which is also an essential ingredient for the
resummation of large logarithms due to soft gluon emissions. We report a recent
analytical calculation of the anomalous dimension matrix with both massless and
massive partons at two-loop level, which describes the two-loop infrared
singularities of any scattering amplitudes with an arbitrary number of massless
and massive partons, and also enables soft gluon resummation at
next-to-next-to-leading-logarithmic order. As an application, we calculate the
infrared poles in the q qbar -> t tbar and gg -> t tbar scattering amplitudes
at two-loop order.


  The penetration of a supersonic particle at the interface was studied in a
binary complex plasma. Inspired by the experiments performed in the PK-3 Plus
Laboratory on board the International Space Station, Langevin dynamics
simulations were carried out. The evolution of Mach cone at the interface was
observed, where a kink of the lateral wake front was observed at the interface.
By comparing the evolution of axial and radial velocity, we show that the
interface solitary wave is non-linear. The dependence of the background
particle dynamics in the vicinity of the interface on the penetration direction
reveals that the disparity of the mobility may be the cause of various
interface effects.


  Under the framework of soft-collinear effective theory, we analyze the
charmless $B\to VV$ decays in a global way at leading power in $1/m_b$ and
leading order in $\alpha_s$ with $V$ denoting a light vector meson. In the
flavor SU(3) symmetry, decay amplitudes for the 28 decay modes are expressed in
terms of 8 nonperturbative parameters. With 35 experimental results, we fit
these 8 nonperturbative parameters. Annihilation contributions are neglected
due to power suppression in the $m_b\to \infty$ limit, so we include in the fit
the nonperturbative charm penguins, which will play an important role in
understanding the direct CP asymmetries. Charming penguins are also responsible
for the large transverse polarizations of penguin-dominated and
color-suppressed decays. With the best fitted parameters, we calculate all
possible physical observables of 28 decay modes, including branching fractions,
direct CP asymmetries, and the complete set of polarization observables. Most
of our results are compatible with the present experimental data when
available, while the others can be examined on the ongoing LHCb experiment and
the forthcoming Belle-II experiment. Moreover, the agreements and differences
with results in QCD factorization and perturbative QCD approach are also
discussed. A few observables are suggested to discriminate these different
approaches.


  The 40Ca(alpha,gamma)44Ti reaction is believed to be the main production
channel for the radioactive nuclide 44Ti in core-collapse supernovae. Radiation
from decaying 44Ti has been observed so far for two supernova remnants, and a
precise knowledge of the 44Ti production rate may help improve supernova
models. The 40Ca(alpha,gamma)44Ti astrophysical reaction rate is determined by
a number of narrow resonances. Here, the resonance triplet at E_alpha = 4497,
4510, and 4523 keV is studied both by activation, using an underground
laboratory for the gamma counting, and by in-beam gamma spectrometry. The
target properties are determined by elastic recoil detection analysis and by
nuclear reactions. The strengths of the three resonances are determined to
omega gamma = (0.92+-0.20), (6.2+-0.5), and (1.32+-0.24) eV, respectively, a
factor of two more precise than before. The strengths of this resonance triplet
may be used in future works as a point of reference. In addition, the present
new data directly affect the astrophysical reaction rate at relatively high
temperatures, above 3.5 GK.


  The absence of self averaging in mesoscopic systems is a consequence of
long-range intensity correlation. Microwave measurements suggest and
diagrammatic calculations confirm that the correlation function of the
normalized intensity with displacement of the source and detector, $\Delta R$
and $\Delta r$, respectively, can be expressed as the sum of three terms, with
distinctive spatial dependences. Each term involves only the sum or the product
of the square of the field correlation function, $F \equiv F_{E}^2$. The
leading-order term is the product, the next term is proportional to the sum.
The third term is proportional to $[F(\Delta R)F(\Delta r) + [F(\Delta
R)+F(\Delta r)] + 1]$.


  Network Creation Games(NCGs) model the creation of decentralized
communication networks like the Internet. In such games strategic agents
corresponding to network nodes selfishly decide with whom to connect to
optimize some objective function. Past research intensively analyzed models
where the agents strive for a central position in the network. This models
agents optimizing the network for low-latency applications like VoIP. However,
with today's abundance of streaming services it is important to ensure that the
created network can satisfy the increased bandwidth demand. To the best of our
knowledge, this natural problem of the decentralized strategic creation of
networks with sufficient bandwidth has not yet been studied.
  We introduce Flow-Based NCGs where the selfish agents focus on bandwidth
instead of latency. In essence, budget-constrained agents create network links
to maximize their minimum or average network flow value to all other network
nodes. Equivalently, this can also be understood as agents who create links to
increase their connectivity and thus also the robustness of the network. For
this novel type of NCG we prove that pure Nash equilibria exist, we give a
simple algorithm for computing optimal networks, we show that the Price of
Stability is 1 and we prove an (almost) tight bound of 2 on the Price of
Anarchy. Last but not least, we show that our models do not admit a potential
function.


  We study a large class of critical two-dimensional Ising models namely
critical Z-invariant Ising models on periodic graphs, example of which are the
classical square, triangular and honeycomb lattice at the critical temperature.
Fisher introduced a correspondence between the Ising model and the dimer model
on a decorated graph, thus setting dimer techniques as a powerful tool for
understanding the Ising model. In this paper, we give a full description of the
dimer model corresponding to the critical Z-invariant Ising model. We prove
that the dimer characteristic polynomial is equal (up to a constant) to the
critical Laplacian characteristic polynomial, and defines a Harnack curve of
genus 0. We prove an explicit expression for the free energy, and for the Gibbs
measure obtained as weak limit of Boltzmann measures.


  We investigate superconformal surface defects in four-dimensional N=2
superconformal theories. Each such defect gives rise to a module of the
associated chiral algebra and the surface defect Schur index is the character
of this module. Various natural chiral algebra operations such as
Drinfeld-Sokolov reduction and spectral flow can be interpreted as
constructions involving four-dimensional surface defects. We compute the index
of these defects in the free hypermultiplet theory and Argyres-Douglas
theories, using both infrared techniques involving BPS states, as well as
renormalization group flows onto Higgs branches. In each case we find perfect
agreement with the predicted characters.


  In a finite distributive lattice $\L$ we define two functions
$s(\alpha)=|\{\delta \in \mathcal{L} | \delta \leq \alpha \}|$ and
$l(\alpha)=|\{\delta \in \mathcal{L} | \delta \geq \alpha \}|$. In this present
article we prove that the sum of these two functions over a finite distributive
lattice are equal. Using this identity we give a formula for the number of
non-comparable pairs of elements in a finite distributive lattice.


  This paper describes a novel idea of a fine-grained fully-active plastic
scintillator detector made of many optically independent
$1\times1\times1~\text{cm}^3$ cubes with readout on three orthogonal
projections by wavelength shifting fibers. The original purpose of this
detector is to serve as an active neutrino target for the detection,
measurement and identification of the final state particles down to a few
tenths MeV kinetic energies. The three readout views as well as the fine
granularity ensure powerful localization and measurement of the deposited
energy combined with good timing properties and isotropic acceptance. The
possible application as a new active target for the T2K near detector, initial
simulation studies and R&D test results are reported.