title: The highly connected even-cycle and even-cut matroids

abstract:
  The classes of even-cycle matroids, even-cycle matroids with a blocking pair,
and even-cut matroids each have hundreds of excluded minors. We show that the
number of excluded minors for these classes can be drastically reduced if we
consider in each class only the highly connected matroids of sufficient size.


title:
Automated Anomaly Detection in Distribution Grids Using $\mu$PMU
  Measurements

abstract:
  The impact of Phasor Measurement Units (PMUs) for providing situational
awareness to transmission system operators has been widely documented.
Micro-PMUs ($\mu$PMUs) are an emerging sensing technology that can provide
similar benefits to Distribution System Operators (DSOs), enabling a level of
visibility into the distribution grid that was previously unattainable. In
order to support the deployment of these high resolution sensors, the
automation of data analysis and prioritizing communication to the DSO becomes
crucial. In this paper, we explore the use of $\mu$PMUs to detect anomalies on
the distribution grid. Our methodology is motivated by growing concern about
failures and attacks to distribution automation equipment. The effectiveness of
our approach is demonstrated through both real and simulated data.


title:
Is Neural Machine Translation Ready for Deployment? A Case Study on 30
  Translation Directions

abstract:
  In this paper we provide the largest published comparison of translation
quality for phrase-based SMT and neural machine translation across 30
translation directions. For ten directions we also include hierarchical
phrase-based MT. Experiments are performed for the recently published United
Nations Parallel Corpus v1.0 and its large six-way sentence-aligned subcorpus.
In the second part of the paper we investigate aspects of translation speed,
introducing AmuNMT, our efficient neural machine translation decoder. We
demonstrate that current neural machine translation could already be used for
in-production systems when comparing words-per-second ratios.


title:
Density Waves Cause Sub-Gap Structures but no Pseudogap in
  Superconducting Cuprates

abstract:
  In scanning tunneling microscopy (STM) conductance curves, the
superconducting gap of cuprates is sometimes accompanied by small sub-gap
structures at very low energy. This was documented early on near vortex cores
and later at zero magnetic field. Using mean-field toy models of coexisting
d-wave superconductivity ($d$SC), \emph{d}-form factor density wave ($d$FF-DW),
and extended s-wave pair density wave ($s'$PDW), we find agreement with this
phenomenon, with $s'$PDW playing a critical role. We explore the high
variability of the gap structure with changes in band structure and density
wave (DW) wave vector, thus explaining why sub-gap structures may not be a
universal feature in cuprates. In the absence of nesting, non-superconducting
results never show signs of pseudogap, even for large density waves magnitudes,
therefore reinforcing the idea of a distinct origin for the pseudogap, beyond
mean-field theory. Therefore, we also briefly consider the effect of DWs on a
pre-existing pseudogap.


title: On the reducibility behaviour of Thue polynomials

abstract:
  We prove a result about reducibility behaviour of Thue polynomials over the
rationals that was conjectured by M\"uller. More precisely, we show that, apart
from few explicitly given exceptions, these polynomials have only finitely many
reducible integer specializations. Special cases have been proved e.g. by
M\"uller and Langmann. The proof uses ramification theory to reduce the
assertion to a statement about permutation groups containing an $n$-cycle. This
statement is finally proven with the help of the classification of primitive
permutation groups containing an $n$-cycle (a result which rests on the
classification of finite simple groups).


title: The Chromatic Number of Ordered Graphs With Constrained Conflict Graphs

abstract:
  An ordered graph $G$ is a graph whose vertex set is a subset of integers. The
edges are interpreted as tuples $(u,v)$ with $u < v$. For a positive integer
$s$, a matrix $M \in \mathbb{Z}^{s \times 4}$, and a vector $\mathbf{p} =
(p,\ldots,p) \in \mathbb{Z}^s$ we build a conflict graph by saying that edges
$(u,v)$ and $(x,y)$ are conflicting if $M(u,v,x,y)^\top \geq \mathbf{p}$ or
$M(x,y,u,v)^\top \geq \mathbf{p}$, where the comparison is componentwise. This
new framework generalizes many natural concepts of ordered and unordered
graphs, such as the page-number, queue-number, band-width, interval chromatic
number and forbidden ordered matchings.
  For fixed $M$ and $p$, we investigate how the chromatic number of $G$ depends
on the structure of its conflict graph. Specifically, we study the maximum
chromatic number $X_\text{cli}(M,p,w)$ of ordered graphs $G$ with no $w$
pairwise conflicting edges and the maximum chromatic number
$X_\text{ind}(M,p,a)$ of ordered graphs $G$ with no $a$ pairwise
non-conflicting edges. We determine $X_\text{cli}(M,p,w)$ and
$X_\text{ind}(M,p,a)$ exactly whenever $M$ consists of one row with entries in
$\{-1,0,+1\}$ and moreover consider several cases in which $M$ consists of two
rows or has arbitrary entries from $\mathbb{Z}$.


title:
Reset-Free Guided Policy Search: Efficient Deep Reinforcement Learning
  with Stochastic Initial States

abstract:
  Autonomous learning of robotic skills can allow general-purpose robots to
learn wide behavioral repertoires without requiring extensive manual
engineering. However, robotic skill learning methods typically make one of
several trade-offs to enable practical real-world learning, such as requiring
manually designed policy or value function representations, initialization from
human-provided demonstrations, instrumentation of the training environment, or
extremely long training times. In this paper, we propose a new reinforcement
learning algorithm for learning manipulation skills that can train
general-purpose neural network policies with minimal human engineering, while
still allowing for fast, efficient learning in stochastic environments. Our
approach builds on the guided policy search (GPS) algorithm, which transforms
the reinforcement learning problem into supervised learning from a
computational teacher (without human demonstrations). In contrast to prior GPS
methods, which require a consistent set of initial states to which the system
must be reset after each episode, our approach can handle randomized initial
states, allowing it to be used in environments where deterministic resets are
impossible. We compare our method to existing policy search techniques in
simulation, showing that it can train high-dimensional neural network policies
with the same sample efficiency as prior GPS methods, and present real-world
results on a PR2 robotic manipulator.


title:
Random 4-regular graphs have 3-star decompositions asymptotically almost
  surely

abstract:
  In 2006, Barat and Thomassen conjectured in 2006 that the edges of every
planar 4-regular 4-edge-connected graph can be decomposed into copies of the
star with 3 leaves. Shortly afterward, Lai constructed a counterexample to this
conjecture. Using the small subgraph conditioning method of Robinson and
Wormald, we prove that a random 4-regular graph has an $S_3$-decomposition
asymptotically almost surely, provided the number of vertices is divisible by
3.


title:
Efficient estimation of the maximum metabolic productivity of batch
  systems

abstract:
  Production of chemicals from engineered organisms in a batch culture involves
an inherent trade-off between productivity, yield, and titer. Existing
strategies for strain design typically focus on designing mutations that
achieve the highest yield possible while maintaining growth viability. While
these methods are computationally tractable, an optimum productivity could be
achieved by a dynamic strategy in which the intracellular division of resources
is permitted to change with time. New methods for the design and implementation
of dynamic microbial processes, both computational and experimental, have
therefore been explored to maximize productivity. However, solving for the
optimal metabolic behavior under the assumption that all fluxes in the cell are
free to vary is a challenging numerical task. This work presents an efficient
method for the calculation of a maximum theoretical productivity of a batch
culture system using a dynamic optimization framework. This metric is analogous
to the maximum theoretical yield, a measure that is well established in the
metabolic engineering literature and whose use helps guide strain and pathway
selection. The proposed method follows traditional assumptions of dynamic flux
balance analysis: (1) that internal metabolite fluxes are governed by a
pseudo-steady state, and (2) that external metabolite fluxes are dynamically
bounded. The optimization is achieved via collocation on finite elements, and
accounts explicitly for an arbitrary number of flux changes. The method can be
further extended to explicitly solve for the trade-off curve between maximum
productivity and yield. We demonstrate the method on succinate production in
two common microbial hosts, Escherichia coli and Actinobacillus succinogenes,
revealing that nearly optimal yields and productivities can be achieved with
only two discrete flux stages.


title:
A strongly-coupled immersed-boundary formulation for thin deforming
  surfaces, with application to elastic beams

abstract:
  We present a strongly-coupled immersed-boundary method for flow-structure
interaction problems involving thin deforming bodies. The method is stable for
arbitrary choices of solid-to-fluid mass ratios and for large body motions. As
with many strongly-coupled immersed-boundary methods, our method requires the
solution of a nonlinear algebraic system at each time step. The system is
solved through iteration, where the iterates are obtained by linearizing the
system and performing a block LU factorization. This restricts all iterations
to small-dimensional subsystems that scale with the number of discretization
points on the immersed surface, rather than on the entire flow domain.
Moreover, the iteration procedure we propose does not involve heuristic
regularization parameters, and has converged in a small number of iterations
for all problems we have considered. We derive our method for general deforming
surfaces, and verify the method with two-dimensional test problems of
geometrically nonlinear beams undergoing large amplitude flapping behavior.


title: Forced Edges and Graph Structure

abstract:
  For a degree sequence, we define the set of edges that appear in every
labeled realization of that sequence as forced, while the edges that appear in
none as forbidden. We examine structure of graphs whose degree sequences
contain either forced or forbidden edges. Among the things we show, we
determine the structure of the forced or forbidden edge sets, the relationship
between the sizes of forced and forbidden sets for a sequence, and the
resulting structural consequences to their realizations. This includes showing
that the diameter of every realization of a degree sequence containing forced
or forbidden edges is no greater than 3, and that these graphs are maximally
edge-connected.


title:
A compact two-phase twisted string actuation system: Modeling and
  validation

abstract:
  In this paper, we propose a compact twisted string actuation system that
achieves a high contraction percentage (81%) on two phases: multi string twist
and overtwist. This type of system can be used in many robotic applications,
such as robotic hands and exoskeletons. The overtwist phase enables the
development of more compact actuators based on the twisted string systems.
Furthermore, by analyzing the previously developed mathematical models, we
found out that a constant radius model should be applied for the overtwisting
phase. Moreover, we propose an improvement of an existing model for prediction
of the radius of the multi string system after they twist around each other.
This model helps to better estimate the bundle diameter which results in a more
precise mathematical model for multi string systems. The model was validated by
performing experiments with 2, 4, 6 and 8 string systems. Finally, we performed
extensive life cycle tests with different loads and contractions to find out
the expected life of the system.


title:
The Limit of Stationary Distributions of Many-Server Queues in the
  Halfin-Whitt Regime

abstract:
  We consider the so-called GI/GI/N queue, in which a stream of jobs with
independent and identically distributed service times arrive as a renewal
process to a common queue that is served by $N$ identical parallel servers in a
first-come-first-serve manner. We introduce a new representation for the state
of the system and, under suitable conditions on the service and interarrival
distributions, establish convergence of the corresponding sequence of centered
and scaled stationary distributions in the so-called Halfin-Whitt asymptotic
regime. In particular, this resolves an open question posed by Halfin and Whitt
in 1981. We also characterize the limit as the stationary distribution of an
infinite-dimensional two-component Markov process that is the unique solution
to a certain stochastic partial differential equation. Previous results were
essentially restricted to exponential service distributions or service
distributions with finite support, for which the corresponding limit process
admits a reduced finite-dimensional Markovian representation. We develop a
different approach to deal with the general case when the Markovian
representation of the limit is truly infinite-dimensional. This approach is
more broadly applicable to a larger class of networks.


title:
Knowledge Guided Disambiguation for Large-Scale Scene Classification
  with Multi-Resolution CNNs

abstract:
  Convolutional Neural Networks (CNNs) have made remarkable progress on scene
recognition, partially due to these recent large-scale scene datasets, such as
the Places and Places2. Scene categories are often defined by multi-level
information, including local objects, global layout, and background
environment, thus leading to large intra-class variations. In addition, with
the increasing number of scene categories, label ambiguity has become another
crucial issue in large-scale classification. This paper focuses on large-scale
scene recognition and makes two major contributions to tackle these issues.
First, we propose a multi-resolution CNN architecture that captures visual
content and structure at multiple levels. The multi-resolution CNNs are
composed of coarse resolution CNNs and fine resolution CNNs, which are
complementary to each other. Second, we design two knowledge guided
disambiguation techniques to deal with the problem of label ambiguity. (i) We
exploit the knowledge from the confusion matrix computed on validation data to
merge ambiguous classes into a super category. (ii) We utilize the knowledge of
extra networks to produce a soft label for each image. Then the super
categories or soft labels are employed to guide CNN training on the Places2. We
conduct extensive experiments on three large-scale image datasets (ImageNet,
Places, and Places2), demonstrating the effectiveness of our approach.
Furthermore, our method takes part in two major scene recognition challenges,
and achieves the second place at the Places2 challenge in ILSVRC 2015, and the
first place at the LSUN challenge in CVPR 2016. Finally, we directly test the
learned representations on other scene benchmarks, and obtain the new
state-of-the-art results on the MIT Indoor67 (86.7\%) and SUN397 (72.0\%). We
release the code and models
at~\url{https://github.com/wanglimin/MRCNN-Scene-Recognition}.


title: Hydrogen atom in a Laser-Plasma

abstract:
  We scrutinize the behaviour of hydrogen atom's eigenvalues in a quantum
plasma as it interacts with electric field directed along $\theta=\pi$ and
exposed to linearly polarized intense laser field radiation. Using the
Kramers-Henneberger (KH) unitary transformation, which is semiclassical
counterpart of the Block-Nordsieck transformation in the quantized field
formalism, the squared vector potential that appears in the equation of motion
is eliminated and the resultant equation is expressed in KH frame. Within this
frame, the resulting potential and the corresponding wavefunction have been
expanded in Fourier series and using Ehlotzky's approximation, we obtain a
laser-dressed potential to simulate intense laser field. By fitting the
exponential-cosine-screened Coulomb potential into the laser-dressed potential,
and then expanding it in Taylor series up to $\mathcal{O}(r^4,\alpha_0^9)$, we
obtain the eigensolution (eigenvalues and wavefunction) of hydrogen atom in
laser-plasma encircled by electric field, within the framework of perturbation
theory formalism. Our numerical results show that for a weak external electric
field and gargantuan length of Debye screening parameter, the system is
strongly repulsive in contrast for strong external electric field and small
length of Debye screening parameter, the system is very attractive. This work
has potential application in the areas of atomic and molecular processes in
external fields including interactions with strong fields and short pulses.


title: Silicon-chip-based mid-infrared dual-comb spectroscopy

abstract:
  On-chip spectroscopy that could realize real-time fingerprinting with
label-free and high-throughput detection of trace molecules is one of the 'holy
grails" of sensing. Such miniaturized spectrometers would greatly enable
applications in chemistry, bio-medicine, material science or space
instrumentation, such as hyperspectral microscopy of live cells or
pharmaceutical quality control. Dual-comb spectroscopy (DCS), a recent
technique of Fourier transform spectroscopy without moving parts, is
particularly promising since it measures high-precision spectra in the gas
phase using only a single detector. Here, we present a microresonator-based
platform designed for mid-infrared (mid-IR) DCS. A single continuous-wave (CW)
low-power pump source generates two mutually coherent mode-locked frequency
combs spanning from 2.6 $\mu$m to 4.1 $\mu$m in two silicon micro-resonators.
Thermal control and free-carrier injection control modelocking of each comb and
tune the dual-comb parameters. The large line spacing of the combs (127 GHz)
and its precise tuning over tens of MHz, unique features of chip-scale comb
generators, are exploited for a proof-of-principle experiment of vibrational
absorption DCS in the liquid phase, with spectra of acetone spanning from 2870
nm to 3170 nm at 127-GHz (4.2-cm$^{-1}$) resolution. We take a significant step
towards a broadband, mid-IR spectroscopy instrument on a chip. With further
system development, our concept holds promise for real-time and time-resolved
spectral acquisition on the nanosecond time scale.


title: Positive factorizations of symmetric mapping classes

abstract:
  We study Question 7.9 in the paper "Monoids in the mapping class group" by
Etnyre and Van Horn-Morris; whether a symmetric mapping class admitting a
positive factorization is a lift of a quasi-positive braid. We answer
affirmatively for mapping classes satisfying certain cyclic conditions.


title:
Effects of vertical confinement on gelation and sedimentation of
  colloids

abstract:
  We consider the sedimentation of a colloidal gel under confinement in the
direction of gravity. The confinement allows us to compare directly experiments
and computer simulations, for the same system size in the vertical direction.
The confinement also leads to qualitatively different behaviour compared to
bulk systems: in large systems gelation suppresses sedimentation, but for small
systems sedimentation is enhanced relative to non-gelling suspensions, although
the rate of sedimentation is reduced when the strength of the attraction
between the colloids is strong. We map interaction parameters between a model
experimental system (observed in real space) and computer simulations.
Remarkably, we find that when simulating the system using Brownian dynamics in
which hydrodynamic interactions between the particles are neglected, we find
that sedimentation occurs on the same timescale as the experiments, however the
thickness of the "arms" of the gel is rather larger in the experiments,
compared with the simulations. An analysis of local structure in the
simulations showed similar behaviour to gelation in the absence of gravity.


title: Critical exponent of quantum phase transitions driven by colored noise

abstract:
  We demonstrate that criticality in a driven-dissipative system is strongly
influenced by the spectral properties of the reservoir. We study the
open-system realization of the Dicke model, where a bosonic cavity mode couples
to a large spin formed by two motional modes of an atomic Bose-Einstein
condensate. The cavity mode is driven by a high frequency laser and it decays
to a Markovian bath, while the atomic mode interacts with a colored reservoir.
We reveal that the soft mode fails to describe the characteristics of the
criticality. We calculate the critical exponent of the superradiant phase
transition and identify an inherent relation to the low-frequency spectral
density function of the colored bath. We show that a finite temperature of the
colored reservoir does not modify qualitatively this dependence on the spectral
density function.


title:
Algebro-Geometric approach for a centrally extended U_q[sl(2|2)]
  R-matrix

abstract:
  In this paper we investigate the algebraic geometric nature of a solution of
the Yang-Baxter equation based on the quantum deformation of the centrally
extended $sl(2|2)$ superalgebra proposed by Beisert and Koroteev \cite{BEKO}.
We derive an alternative representation for the $\mathrm{R}$-matrix in which
the matrix elements are given in terms of rational functions depending on
weights sited on a degree six surface. For generic gauge the weights geometry
are governed by a genus one ruled surface while for a symmetric gauge choice
the weights lie instead on a genus five curve. We have written down the
polynomial identities satisfied by the $\mathrm{R}$-matrix entries needed to
uncover the corresponding geometric properties. For arbitrary gauge the
$\mathrm{R}$-matrix geometry is argued to be birational to the direct product
$\mathbb{CP}^1 \times \mathbb{CP}^1 \times \mathrm{A}$ where $\mathrm{A}$ is an
Abelian surface. For the symmetric gauge we present evidences that the
geometric content is that of a surface of general type lying on the so-called
Severi line with irregularity two and geometric genus nine. We discuss
potential geometric degenerations when the two free couplings are restricted to
certain one-dimensional subspaces.


title: Operators for scattering of particles with spin

abstract:
  Operators for simulating the scattering of two particles with spin are
constructed. Three methods are shown to give the consistent lattice operators
for PN, PV, VN and NN scattering, where P, V and N denote pseudoscalar meson,
vector meson and nucleon. The projection method leads to one or several
operators $O_{\Gamma,r,n}$ that transform according to a given irreducible
representation $\Gamma$ and row r. However, it gives little guidance on which
continuum quantum numbers of total J, spin S, orbital momentum L or
single-particle helicities $\lambda_{1,2}$ will be related with a given
operator. This is remedied with the helicity and partial-wave methods. There
first the operators with good continuum quantum numbers $(J,P,\lambda_{1,2})$
or $(J,L,S)$ are constructed and then subduced to the irreps $\Gamma$ of the
discrete lattice group. The results indicate which linear combinations
$O_{\Gamma,r,n}$ of various n have to be employed in the simulations in order
to enhance couplings to the states with desired continuum quantum numbers. The
total momentum of two hadrons is restricted to zero since parity P is a good
quantum number in this case.


title:
Mechanism for long-acting chimeras based on fusion with the
  carboxyl-terminal peptide (CTP) of human chorionic gonadotropin beta-subunit
  3

abstract:
  Thermodynamic scaling explains the dramatic successes of CTP fused human
growth proteins as regards lifetime in vivo and enhanced functionality compared
to their wild-type analogues, like Biogen. The theory is semi-quantitative and
contains no adjustable parameters. It shows how hydrophilic terminal spheres
orient fused proteins in the neighborhood of a membrane surface, extending
lifetimes and improving functionality.


title:
A dynamic Laplacian for identifying Lagrangian coherent structures on
  weighted Riemannian manifolds

abstract:
  Transport and mixing in dynamical systems are important properties for many
physical, chemical, biological, and engineering processes. The detection of
transport barriers for dynamics with general time dependence is a difficult,
but important problem, because such barriers control how rapidly different
parts of phase space (which might correspond to different chemical or
biological agents) interact. The key factor is the growth of interfaces that
partition phase space into separate regions. The paper [Froyland, Nonlinearity
2015] introduced the notion of \textit{dynamic isoperimetry}: the study of sets
with persistently small boundary size (the interface) relative to enclosed
volume, when evolved by the dynamics. Sets with this minimal boundary size to
volume ratio were identified as level sets of dominant eigenfunctions of a
\textit{dynamic Laplace operator}.
  In this present work we extend the results of [Froyland, Nonlinearity 2015]
to the situation where the dynamics (i) is not necessarily volume-preserving,
(ii) acts on initial agent concentrations different from uniform
concentrations, and (iii) occurs on a possibly curved phase space. Our main
results include generalised versions of the dynamic isoperimetric problem, the
dynamic Laplacian, Cheeger's inequality, and the Federer-Fleming theorem. We
illustrate the computational approach with some simple numerical examples.


title:
Accretion on Reissner-Nordstrom-(anti)-de Sitter Black Hole with Global
  Monopole

abstract:
  In this paper, we investigate the accretion on the Reissner-Nordstr\"{o}m
anti-de-Sitter black hole with global monopole charge. We discuss the general
solutions of accretion using the isothermal and polytropic equations of state
for steady state, spherically symmetric, non-rotating accretion on the black
hole. In the case of isothermal flow, we consider some specific fluids and
derive their solutions at the sonic point as well. However, in case of
polytropic fluid we calculate the general expressions only, as there exists no
global (Bondi) solutions for polytropic test fluids. In addition to this, the
effect of fluid on the mass accretion rate are also studied. Moreover, the
large monopole parameter $\beta$ greatly suppresses the maximum accretion rate.


title:
Linde problem in Yang-Mills theory compactified on $\mathbb{R}^2 \times
  \mathbb{T}^2$

abstract:
  We investigate the perturbative expansion in $SU(3)$ Yang-Mills theory
compactified on $\mathbb{R}^2\times \mathbb{T}^2$ where the compact space is a
torus $\mathbb{T}^2= S^1_{\beta}\times S^1_{L}$, with $S^1_{\beta}$ being a
thermal circle with period $\beta=1/T$ ($T$ is the temperature) while $S^1_L$
is a circle with finite length $L=1/M$, where $M$ is an energy scale. A
Linde-type analysis indicates that perturbative calculations for the pressure
in this theory break down already at order $\mathcal{O}(g^2)$ due to the
presence of a non-perturbative scale $\sim g \sqrt{TM}$. We conjecture that a
similar result should hold if the torus is replaced by any other compact
surface of genus one.


title: The Anomalous de Haas-van Alphen Effect in InAs/GaSb quantum wells

abstract:
  The de Haas-van Alphen effect (dHvAe) describes the periodic oscillation of
the magnetisation in a material as a function of inverse applied magnetic
field. It forms the basis of a well established procedure for measuring Fermi
surface properties and its observation is typically taken as a direct signature
of a system being metallic. However, certain insulators can show similar
oscillations of the magnetisation from quantisation of the energies of electron
states in filled bands. Recently the theory of such an ${\it anomalous}$ dHvAe
(AdHvAe) has been worked out but so far there is no clear experimental
observation. Here, we show that the inverted narrow gap regime of InAs/GaSb
quantum wells is an ideal platform for the observation of the AdHvAe. From our
microscopic calculations we make quantitative predictions for the relevant
magnetic field and temperature regimes, and describe unambiguous experimental
signatures.


title:
A Non-generative Framework and Convex Relaxations for Unsupervised
  Learning

abstract:
  We give a novel formal theoretical framework for unsupervised learning with
two distinctive characteristics. First, it does not assume any generative model
and based on a worst-case performance metric. Second, it is comparative, namely
performance is measured with respect to a given hypothesis class. This allows
to avoid known computational hardness results and improper algorithms based on
convex relaxations. We show how several families of unsupervised learning
models, which were previously only analyzed under probabilistic assumptions and
are otherwise provably intractable, can be efficiently learned in our framework
by convex optimization.


title: Mathematical Execution: A Unified Approach for Testing Numerical Code

abstract:
  This paper presents Mathematical Execution (ME), a new, unified approach for
testing numerical code. The key idea is to (1) capture the desired testing
objective via a representing function and (2) transform the automated testing
problem to the minimization problem of the representing function. The
minimization problem is to be solved via mathematical optimization. The main
feature of ME is that it directs input space exploration by only executing the
representing function, thus avoiding static or symbolic reasoning about the
program semantics, which is particularly challenging for numerical code. To
illustrate this feature, we develop an ME-based algorithm for coverage-based
testing of numerical code. We also show the potential of applying and adapting
ME to other related problems, including path reachability testing, boundary
value analysis, and satisfiability checking.
  To demonstrate ME's practical benefits, we have implemented CoverMe, a
proof-of-concept realization for branch coverage based testing, and evaluated
it on Sun's C math library (used in, for example, Android, Matlab, Java and
JavaScript). We have compared CoverMe with random testing and Austin, a
publicly available branch coverage based testing tool that supports numerical
code (Austin combines symbolic execution and search-based heuristics). Our
experimental results show that CoverMe achieves near-optimal and substantially
higher coverage ratios than random testing on all tested programs, across all
evaluated coverage metrics. Compared with Austin, CoverMe improves branch
coverage from 43% to 91%, with significantly less time (6.9 vs. 6058.4 seconds
on average).


title: The Cayley-Dickson Construction in Homotopy Type Theory

abstract:
  We define in the setting of homotopy type theory an H-space structure on
$\mathbb S^3$. Hence we obtain a description of the quaternionic Hopf fibration
$\mathbb S^3\hookrightarrow\mathbb S^7\twoheadrightarrow\mathbb S^4$, using
only homotopy invariant tools.


title:
Non-Hermiticity-Induced Wave Confinement and Guiding in Loss-Gain-Loss
  Three-Layer Systems

abstract:
  Following up on previous studies on parity-time-symmetric gain-loss
bi-layers, and inspired by formal analogies with plasmonic waveguides, we study
non-Hermiticity-induced wave confinement and guiding phenomena that can occur
in loss-gain-loss three-layers. By revisiting previous well-established
"gain-guiding" concepts, we investigate analytically and numerically the
dispersion and confinement properties of guided modes that can be supported by
this type of structures, by assuming realistic dispersion models and parameters
for the material constituents. As key outcomes, we identify certain modes with
specific polarization and symmetry that exhibit particularly desirable
characteristics, in terms of quasi-real propagation constant and sub-wavelength
confinement. Moreover, we elucidate the effects of material dispersion and
parameters, and highlight the potential advantages by comparison with the
previously studied gain-loss bi-layer configurations. Our results provide
additional perspectives on light control in non-Hermitian optical systems, and
may find potentially intriguing applicability to reconfigurable nanophotonic
platforms.


title: Massey products in mapping tori

abstract:
  Let $\phi: M\to M$ be a diffeomorphism of a $C^\infty$ compact connected
manifold, and $X$ its mapping torus. There is a natural fibration $p:X\to S^1$,
denote by $\xi\in H^1(X, \mathbb{Z})$ the corresponding cohomology class. Let
$\lambda\in \mathbb{Z}^*$. Consider the endomorphism $\phi_k^*$ induced by
$\phi$ in the cohomology of $M$ of degree $k$, and denote by $J_k(\lambda)$ the
maximal size of its Jordan block of eigenvalue $\lambda$. Define a
representation $\rho_\lambda : \pi_1(X)\to\mathbb{C}^*$ by $\rho_\lambda (g) =
\lambda^{p_*(g)}.$ Let $H^*(X,\rho_\lambda)$ be the corresponding twisted
cohomology of $X$. We prove that $J_k(\lambda)$ is equal to the maximal length
of a non-zero Massey product of the form $\langle \xi, \ldots , \xi, a\rangle$
where $a\in H^k(X,\rho_\lambda)$ (here the length means the number of entries
of $\xi$). In particular, if $X$ is a strongly formal space (e.g. a K\"ahler
manifold) then all the Jordan blocks of $\phi_k^*$ are of size 1. If $X$ is a
formal space, then all the Jordan blocks of eigenvalue 1 are of size 1. This
leads to a simple construction of formal but not strongly formal mapping tori.
The proof of the main theorem is based on the fact that the Massey products of
the above form can be identified with differentials in a Massey spectral
sequence, which in turn can be explicitly computed in terms of the Jordan
normal form of $\phi^*$.


title:
It\^o type stochastic differential equations driven by fractional
  Brownian motions of Hurst parameter $H>1/2$

abstract:
  This paper studies the existence and uniqueness of solution of It\^o type
stochastic differential equation $dx(t)=b(t, x(t), \om)dt+\si(t,x(t), \om) d
B(t)$, where $B(t)$ is a fractional Brownian motion of Hurst parameter $H>1/2$
and $dB(t)$ is the It\^o differential defined by using Wick product or
divergence operator. The coefficients $b$ and $\si$ are random and can be
anticipative. Using the relationship between the It\^o type and pathwise
integrals we first write the equation as a stochastic differential equation
involving pathwise integral plus a Malliavin derivative term. To handle this
Malliavin derivative term the equation is then further reduced to a system of
(two) equations without Malliavin derivative. The reduced system of equations
are solved by a careful analysis of Picard iteration, with a new technique to
replace the Gr\"onwall lemma which is no longer applicable. The solution of
this system of equations is then applied to solve the original It\^o type
stochastic differential equation up to a positive random time. In the special
linear and quasilinear cases the global solutions are proved to exist uniquely.


title:
How does Quantum Uncertainty Emerge from Deterministic Bohmian
  Mechanics?

abstract:
  Bohmian mechanics is a theory that provides a consistent explanation of
quantum phenomena in terms of point particles whose motion is guided by the
wave function. In this theory, the state of a system of particles is defined by
the actual positions of the particles and the wave function of the system; and
the state of the system evolves deterministically. Thus, the Bohmian state can
be compared with the state in classical mechanics, which is given by the
positions and momenta of all the particles, and which also evolves
deterministically. However, while in classical mechanics it is usually taken
for granted and considered unproblematic that the state is, at least in
principle, measurable, this is not the case in Bohmian mechanics. Due to the
linearity of the quantum dynamical laws, one essential component of the Bohmian
state, the wave function, is not directly measurable. Moreover, it turns out
that the measurement of the other component of the state -the positions of the
particles- must be mediated by the wave function; a fact that in turn implies
that the positions of the particles, though measurable, are constrained by
absolute uncertainty. This is the key to understanding how Bohmian mechanics,
despite being deterministic, can account for all quantum predictions, including
quantum randomness and uncertainty.


title: Kinetics of motility-induced phase separation and swim pressure

abstract:
  Active Brownian particles (ABPs) represent a minimal model of active matter
consisting of self-propelled spheres with purely repulsive interactions and
rotational noise. Here, we examine the pressure of ABPs in two dimensions in
both closed boxes and systems with periodic boundary conditions and show that
its nonmonotonic behavior with density is a robust feature, independent of
system size. We correlate the time evolution of the mean pressure towards its
steady state value with the kinetics of motility-induced phase separation. For
parameter values corresponding to phase separated steady states, we identify
two dynamical regimes. The pressure grows monotonically in time during the
initial regime of rapid cluster formation, overshooting its steady state value
and then quickly relaxing to it, and remains constant during the subsequent
slower period of cluster coalescence and coarsening. The overshoot is a
distinctive feature of active systems.


title: Reasoning about identifier spaces: How to make Chord correct

abstract:
  The Chord distributed hash table (DHT) is well-known and often used to
implement peer-to-peer systems. Chord peers find other peers, and access their
data, through a ring-shaped pointer structure in a large identifier space.
Despite claims of proven correctness, i.e., eventual reachability, previous
work has shown that the Chord ring-maintenance protocol is not correct under
its original operating assumptions. Previous work has not, however, discovered
whether Chord could be made correct under the same assumptions. The
contribution of this paper is to provide the first specification of correct
operations and initialization for Chord, an inductive invariant that is
necessary and sufficient to support a proof of correctness, and two independent
proofs of correctness. One proof is informal and intuitive, and applies to
networks of any size. The other proof is based on a formal model in Alloy, and
uses fully automated analysis to prove the assertions for networks of bounded
size. The two proofs complement each other in several important ways.


title:
An observational study of dust nucleation in Mira ($o$ Ceti): II.
  Titanium oxides are negligible for nucleation at high temperatures

abstract:
  The formation of silicate dust in oxygen-rich envelopes of evolved stars is
thought to be initiated by formation of seed particles that can withstand the
high temperatures close to the stellar photosphere and act as condensation
cores farther away from the star. Candidate species considered as first
condensates are TiO and TiO$_2$. We aim to identify and characterize the
circumstellar gas-phase chemistry of titanium that leads to the formation of
solid titanium compounds in the envelope of $o$ Cet, the prototypical Mira, and
seek an observational verification of whether titanium oxides play a major role
in the onset of dust formation in M-type AGB stars. We present high
angular-resolution ALMA observations at submillimeter (submm) wavelengths
supplemented by APEX and Herschel spectra of the rotational features of TiO and
TiO$_2$. In addition, circumstellar features of TiO and TiI are identified in
optical spectra which cover multiple pulsation cycles of $o$ Cet. The submm
ALMA data reveal TiO and TiO$_2$ bearing gas within the extended atmosphere of
Mira. While TiO is traceable up to a radius (FWHM/2) of 4.0 R$_{\star}$,
TiO$_2$ extends as far as 5.5 R$_{\star}$ and unlike TiO appears to be
anisotropically distributed. Optical spectra display variable emission of TiI
and TiO from inner parts of the extended atmosphere (<3 R$_{\star}$). Chemical
models which include shocks are in general agreement with the observations of
gas-phase titanium-bearing molecules. It is unlikely that substantial amounts
of titanium is locked up in solids because the abundance of the gaseous
titanium species is very high. In particular, formation of hot titanium-rich
condensates is very improbable because we find no traces of their hot precursor
species in the gas phase. It therefore appears unlikely that the formation of
dust in Mira, and possibly other M-type AGB stars, is initiated by titanium
oxides.


title: Spin on a 4D Feynman Checkerboard

abstract:
  We discretize the Weyl equation for a massless, spin-1/2 particle on a
time-diagonal, hypercubic spacetime lattice with null faces. The amplitude for
a step of right-handed chirality is proportional to the spin projection
operator in the step direction, while for left-handed it is the orthogonal
projector. Iteration yields a path integral for the retarded propagator, with
matrix path amplitude proportional to the product of projection operators. This
assigns the amplitude $i^{\pm T}\, {3}^{-B/2}\,2^{-N}$ to a path with $N$
steps, $B$ bends, and $T$ right-handed minus left-handed bends, where the sign
corresponds to the chirality. Fermion doubling does not occur in this discrete
scheme. A Dirac mass $m$ introduces the amplitude $i\epsilon m$ to flip
chirality in any given time step $\epsilon$, and a Majorana mass similarly
introduces a charge conjugation amplitude.


title:
Dynamics of mode-coupling-induced microresonator frequency combs in
  normal dispersion

abstract:
  We experimentally and theoretically investigate the dynamics of
microresonator-based frequency comb generation assisted by mode coupling in the
normal group-velocity dispersion (GVD) regime. We show that mode coupling can
initiate intracavity modulation instability (MI) by directly perturbing the
pump-resonance mode. We also observe the formation of a low-noise comb as the
pump frequency is tuned further into resonance from the MI point. We determine
the phase-matching conditions that accurately predict all the essential
features of the MI and comb spectra, and extend the existing analogy between
mode coupling and high-order dispersion to the normal GVD regime. We discuss
the applicability of our analysis to the possibility of broadband comb
generation in the normal GVD regime.


title: The slow death of most galaxies

abstract:
  For most galaxies, the shutdown of star formation was a slow process that
took four billion years. An analysis of thousands of galaxies suggests that
'strangulation' by their environment was the most likely cause. See Letter on
page 192 of Peng, Maiolino and Cochrane (2015), Nature, vol. 521.


title: Error bounds for approximations with deep ReLU networks

abstract:
  We study expressive power of shallow and deep neural networks with piece-wise
linear activation functions. We establish new rigorous upper and lower bounds
for the network complexity in the setting of approximations in Sobolev spaces.
In particular, we prove that deep ReLU networks more efficiently approximate
smooth functions than shallow networks. In the case of approximations of 1D
Lipschitz functions we describe adaptive depth-6 network architectures more
efficient than the standard shallow architecture.


title: Background model for the MAJORANA DEMONSTRATOR

abstract:
  The MAJORANA Collaboration is constructing a system containing 44 kg of
high-purity Ge (HPGe) detectors to demonstrate the feasibility and potential of
a future tonne-scale experiment capable of probing the neutrino mass scale to
~15 meV. To realize this, a major goal of the MAJORANA DEMONSTRATOR is to
demonstrate a path forward to achieving a background rate at or below 1
count/(ROI-t-y) in the 4 keV region of interest (ROI) around the Q-value at
2039 keV. This goal is pursued through a combination of a significant reduction
of radioactive impurities in construction materials and analytical methods for
background rejection, for example using powerful pulse shape analysis
techniques profiting from the p-type point contact HPGe detectors technology.
The effectiveness of these methods is assessed using simulations of the
different background components whose purity levels are constrained from
radioassay measurements. Preliminary background results obtained during the
engineering runs of the Demonstrator are presented.


title: Nonlinear Characteristics of Neural Signals

abstract:
  The study is devoted to definition of generalized metrical and topological
(informational entropy) characteristics of neural signals via their well-known
theoretical models. We have shown that time dependence of action potential of
neurons is scale invariant. Information and entropy of neural signals have
constant values in case of self-similarity and self-affinity.


title: Gravitational wave detection in space

abstract:
  Gravitational wave (GW) detection in space is aimed at low frequency band
(100 nHz - 100 mHz) and middle frequency band (100 mHz - 10 Hz). The science
goals are the detection of GWs from (i) Supermassive Black Holes; (ii)
Extreme-Mass-Ratio Black Hole Inspirals; (iii) Intermediate-Mass Black Holes;
(iv) Galactic Compact Binaries and (v) Relic GW Background. In this paper, we
present an overview on the sensitivity, orbit design, basic orbit
configuration, angular resolution, orbit optimization, deployment, time-delay
interferometry and payload concept of the current proposed GW detectors in
space under study. The detector proposals under study have arm length ranging
from 1000 km to 1.3 x 109 km (8.6 AU) including (a) Solar orbiting detectors --
ASTROD-GW (ASTROD [Astrodynamical Space Test of Relativity using Optical
Devices] optimized for GW detection), BBO (Big Bang Observer), DECIGO
(DECi-hertz Interferometer GW Observatory), e-LISA (evolved LISA [Laser
Interferometer Space Antenna]), LISA, other LISA-type detectors such as ALIA,
TAIJI etc. (in Earth-like solar orbits), and Super-ASTROD (in Jupiter-like
solar orbits); and (b) Earth orbiting detectors -- ASTROD-EM/LAGRANGE,
GADFLI/GEOGRAWI/g-LISA, OMEGA and TIANQIN.

categories: astro-ph.IM astro-ph.CO astro-ph.GA gr-qc


title: Taylor's Law of temporal fluctuation scaling in stock illiquidity

abstract:
  Taylor's law of temporal fluctuation scaling, variance $\sim$ $a($mean$)^b$,
is ubiquitous in natural and social sciences. We report for the first time
convincing evidence of a solid temporal fluctuation scaling law in stock
illiquidity by investigating the mean-variance relationship of the
high-frequency illiquidity of almost all stocks traded on the Shanghai Stock
Exchange (SHSE) and the Shenzhen Stock Exchange (SZSE) during the period from
1999 to 2011. Taylor's law holds for A-share markets (SZSE Main Board, SZSE
Small & Mediate Enterprise Board, SZSE Second Board, and SHSE Main Board) and
B-share markets (SZSE B-share and SHSE B-share). We find that the scaling
exponent $b$ is greater than 2 for the A-share markets and less than 2 for the
B-share markets. We further unveil that Taylor's law holds for stocks in 17
industry categories, in 28 industrial sectors and in 31 provinces and
direct-controlled municipalities with the majority of scaling exponents
$b\in(2,3)$. We also investigate the $\Delta{t}$-min illiquidity and find that
the scaling exponent $b(\Delta{t})$ increases logarithmically for small
$\Delta{t}$ values and decreases fast to a stable level.


title: A recursive algorithm for a pipeline maintenance scheduling problem

abstract:
  This paper deals with the problem of preventive maintenance (PM) scheduling
of pipelines subject to external corrosion defects. The preventive maintenance
strategy involves an inspection step at some epoch, together with a repair
schedule. This paper proposes to determine the repair schedule as well as an
inspection time minimizing the maintenance cost. This problem is formulated as
a binary integer non-linear programming model and we approach it under a
decision support framework. We derive a polynomial-time algorithm that computes
the optimum PM schedule and suggests different PM strategies in order to assist
practitioners in making decision.


title: Entropic gravity from noncommutative black holes

abstract:
  In this paper we will investigate the effects of a noncommutative (NC)
space-time on the dynamics of the universe. We will generalize the black hole
entropy formula for a NC black hole. Then, using the entropic gravity
formalism, we will show that the noncommutativity changes the strength of the
gravitational field. By applying this result to a homogeneous and isotropic
universe containing nonrelativistic matter and a cosmological constant, we will
show that the model modified by the noncommutativity of the space-time is a
better fit to the obtained data than the standard one.


title: The Hardy's nonlocality argument

abstract:
  Certain predictions of quantum theory are not compatible with the notion of
local-realism. This was the content of Bell's famous theorem of the year 1964.
Bell proved this with the help of an inequality, famously known as Bell's
inequality. The alternative proofs of Bell's theorem without using Bell's
inequality are known as `nonlocality without inequality (NLWI)' proofs. We,
review one such proof, namely the Hardy's proof which due to its simplicity and
generality has been considered the best version of Bell's theorem.


title:
Integration of higher IT education in Ukraine in the global
  IT-educational space

abstract:
  The article presents the results of a study of the current state of higher IT
education system in Ukraine. The problems of reforming higher IT education
system of Ukraine in accordance with the commitments made by Ukraine in
connection with the ratification of the EU-Ukraine Agreement Law of Ukraine N
1678-VII of September 16, 2014. An indicator of the presence or absence of a
real reform of the system of higher IT education in Ukraine is detected. A
comparative analysis of lists of IT-specialties of higher education in Ukraine
in 2005 and 2015 with similar lists adopted by the international system of
higher IT education is made. A discrepancy between the list of IT-specialties
in Ukraine and international list of IT specialties are identified. The
conclusion about the need for immediate correction of the list of higher
education in Ukraine IT-specialties in order to bring it into line with
international standards. It recommended a series of actions that will lead to
the solution of the problem.


title: Generation of circular polarization of gamma ray bursts

abstract:
  The generation of the circular polarization of Gamma Ray Burst (GRB) photons
is discussed in this paper via their interactions with astroparticles in the
presence or absence of background fields such as magnetic fields and
non-commutative space time geometry. Solving quantum Boltzmann equation for
GRB-photons as a photon ensemble, we discuss the generation of circular
polarization (as Faraday conversion phase shift $\Delta \phi_{FC}$) of GRBs in
the following cases: (i) intermediate interactions, i.e. the Compton scattering
of GRBs in the galaxy cluster magnetic field and in the presence of
non-commutative space time geometry, as well as the scattering of GRBs in
cosmic neutrino background (CNB), and in cosmic microwave background (CMB);
(ii) interactions with particles and fields in shock wave, i.e. the Compton
scattering of GRBs with accelerated charged particles in the presence of
magnetic fields. We found that (i) after shock wave crossing, the most
contribution of $\Delta \phi_{FC}$ for energetic GRBs (in order GeV and larger)
comes from GRB-CMB interactions, however for low energy GRBs the contributions
of the Compton scattering of GRBs in the galaxy cluster magnetic field
dominate; (ii) in shock wave crossing, the magnetic filed has significant
effects on converting GRB's linear polarization to circular one, this effect
can be used to better understanding magnetic profile in shock wave. The main
aim of this work is a emphasis that the studying and measuring the circular
polarization of GRBs are helpful for better understanding of physics and
mechanism of the generation of GRBs and their interactions before reaching us.


title:
Cosmological Hydrodynamic Simulations of Preferential Accretion in the
  SMBH of Milky Way Size Galaxies

abstract:
  Using a new, high-resolution cosmological hydrodynamic simulation of a Milky
Way-type (MW-type) galaxy, we explore how a merger-rich assembly history
affects the mass budget of the central supermassive black hole (SMBH). We
examine a MW-mass halo at the present epoch whose evolution is characterized by
several major mergers to isolate the importance of merger history on black hole
accretion. This study is an extension of Bellovary et. al. 2013, which analyzed
the accretion of high mass, high redshift galaxies and their central black
holes, and found that the gas content of the central black hole reflects what
is accreted by the host galaxy halo. In this study, we find that a merger-rich
galaxy will have a central SMBH preferentially fed by merger gas. Moreover, we
find that nearly 30$\%$ of the accreted mass budget of the SMBH enters the
galaxy through the two major mergers in its history, which may account for the
increase of merger-gas fueling the SMBH. Through an investigation of the
angular momentum of the gas entering the host and its SMBH, we determine that
merger gas enters the galaxy with lower angular momentum compared to smooth
accretion, partially accounting for the preferential fueling witnessed in the
SMBH. In addition, the presence of mergers, particularly major mergers, also
helps funnel low angular momentum gas more readily to the center of the galaxy.
Our results imply that galaxy mergers play an important role in feeding the
SMBH in MW-type galaxies with merger-rich histories. Our results imply that
galaxy mergers play an important role in feeding the SMBH in MW-type galaxies
with merger-rich histories.


title:
Massive Close Pairs Measure Rapid Galaxy Assembly in Mergers at High
  Redshift

abstract:
  We compare mass-selected close pairs at z > 1 with the intrinsic galaxy
merger rate in the Illustris Simulations. To do so, we construct three 140
arcmin^2 lightcone catalogs and measure pair fractions, finding that they
change little or decrease with increasing redshift at z > 1. Consistent with
current surveys, this trend requires a decrease in the merger-pair
observability time, roughly as (1 + z)^-2, in order to measure the merger rates
of the same galaxies. This implies that major mergers are more common at high
redshift than implied by the simplest arguments assuming a constant
observability time. Several effects contribute to this trend: (1) The fraction
of massive, major (4:1) pairs which merge by today increases weakly from ~0.5
at z=1 to ~0.8 at z=3. (2) The median time elapsed between an observed pair and
final remnant decreases by a factor of two from z~1 to z~3. (3) An increasing
specific star formation rate (sSFR) decreases the time during which common
stellar-mass based pair selection criteria could identify the mergers. The
average orbit of the pairs at observation time varies only weakly, suggesting
that the dynamical time is not varying enough to account by itself for the pair
fraction trends. Merging pairs reside in dense regions, having overdensity ~10
to ~100 times greater than the average massive galaxy. We forward model the
pairs to reconstruct the merger remnant production rate, showing that it is
consistent with a rapid increase in galaxy merger rates at z > 1.


title:
Off-axis emission of short gamma-ray bursts and the detectability of
  electromagnetic counterparts of gravitational wave detected binary mergers

abstract:
  We present calculations of the wide angle emission of short-duration
gamma-ray bursts from compact binary merger progenitors. Such events are
expected to be localized by their gravitational wave emission, fairly
irrespective of the orientation of the angular momentum vector of the system,
along which the gamma-ray burst outflow is expected to propagate. We show that
both the prompt and afterglow emission are dim and challenging to detect for
observers lying outside of the cone within which the relativistic outflow is
propagating. If the jet initially propagates through a baryon contaminated
region surrounding the merger site, however, a hot cocoon forms around it. The
cocoon subsequently expands quasi-isotropically producing its own prompt
emission and external shock powered afterglow. We show that the cocoon prompt
emission is detectable by Swift BAT and Fermi GBM, We also show that the cocoon
afterglow peaks a few hours to a few days after the burst and is detectable for
up to a few weeks at all wavelengths. The timing and brightness of the
transient are however uncertain due to their dependence on unknown quantities
such as the density of the ambient medium surrounding the merger site, the
cocoon energy, and the cocoon Lorentz factor. For a significant fraction of the
gravitationally-detected neutron-star-binary mergers, the cocoon afterglow
could possibly be the only identifiable electromagnetic counterpart, at least
at radio and X-ray frequencies.


title:
The PAndAS view of the Andromeda satellite system - II. Detailed
  properties of 23 M31 dwarf spheroidal galaxies

abstract:
  We present a comprehensive analysis of the structural properties and
luminosities of the 23 dwarf spheroidal galaxies that fall within the footprint
of the Pan-Andromeda Archaeological Survey (PAndAS). These dwarf galaxies
represent the large majority of Andromeda's known satellite dwarf galaxies and
cover a wide range in luminosity ($-11.6<M_V<-5.8$ or $10^{4.2}< L <10^{6.5}
L_\odot$) and surface brightness ($25.1<\mu_0<29.3$ mag/arcsec$^2$). We confirm
most previous measurements, but find And XIX to be significantly larger than
before ($r_h=3065^{+1065}_{-935}$ pc, $M_V=-10.1^{+0.8}_{-0.4}$) and cannot
derive parameters for And XXVII as it is likely not a bound stellar system. We
also significantly revise downward the luminosities of And~XV and And~XVI,
which are now $M_V\sim-7.5$ or $L\sim10^5 L_\odot$. Finally, we provide the
first detailed analysis of Cas II/And XXX, a fairly faint system
($M_V=-8.0^{+0.4}_{-0.3}$) of typical size ($r_h=270\pm50$ pc), located in
close proximity to the two bright elliptical dwarf galaxies NGC 147 & 185.
Combined with the set of homogeneous distances published in an earlier
contribution, our analysis dutifully tracks all relevant sources of uncertainty
in the determination of the properties of the dwarf galaxies from the PAndAS
photometric catalogue. We further publish the posterior probability
distribution functions of all the parameters we fit for in the form of MCMC
chains available online; these inputs should be used in any analysis that aims
to remain truthful to the data and properly account for covariance between
parameters.


title:
The Auriga Project: the properties and formation mechanisms of disc
  galaxies across cosmic time

abstract:
  We introduce a suite of thirty cosmological magneto-hydrodynamical zoom
simulations of the formation of galaxies in isolated Milky Way mass dark
haloes. These were carried out with the moving mesh code \textlcsc{AREPO},
together with a comprehensive model for galaxy formation physics, including AGN
feedback and magnetic fields, which produces realistic galaxy populations in
large cosmological simulations. We demonstrate that our simulations reproduce a
wide range of present-day observables, in particular, two component disc
dominated galaxies with appropriate stellar masses, sizes, rotation curves,
star formation rates and metallicities. We investigate the driving mechanisms
that set present-day disc sizes/scale lengths, and find that they are related
to the angular momentum of halo material. We show that the largest discs are
produced by quiescent mergers that inspiral into the galaxy and deposit high
angular momentum material into the pre-existing disc, simultaneously increasing
the spin of dark matter and gas in the halo. More violent mergers and strong
AGN feedback play roles in limiting disc size by destroying pre-existing discs
and by suppressing gas accretion onto the outer disc, respectively. The most
important factor that leads to compact discs, however, is simply a low angular
momentum for the halo. In these cases, AGN feedback plays an important role in
limiting central star formation and the formation of a massive bulge.


title: Selection biases in empirical p(z) methods for weak lensing

abstract:
  To measure the mass of foreground objects with weak gravitational lensing,
one needs to estimate the redshift distribution of lensed background sources.
This is commonly done in an empirical fashion, i.e. with a reference sample of
galaxies of known spectroscopic redshift, matched to the source population. In
this work, we develop a simple decision tree framework that, under the ideal
conditions of a large, purely magnitude-limited reference sample, allows an
unbiased recovery of the source redshift probability density function p(z), as
a function of magnitude and color. We use this framework to quantify biases in
empirically estimated p(z) caused by selection effects present in realistic
reference and weak lensing source catalogs, namely (1) complex selection of
reference objects by the targeting strategy and success rate of existing
spectroscopic surveys and (2) selection of background sources by the success of
object detection and shape measurement at low signal-to-noise. For
intermediate-to-high redshift clusters, and for depths and filter combinations
appropriate for ongoing lensing surveys, we find that (1) spectroscopic
selection can cause biases above the 10 per cent level, which can be reduced to
5 per cent by optimal lensing weighting, while (2) selection effects in the
shape catalog bias mass estimates at or below the 2 per cent level. This
illustrates the importance of completeness of the reference catalogs for
empirical redshift estimation.


title: Nonlocal Symmetries, Spectral Parameter and Minimal Surfaces in AdS/CFT

abstract:
  We give a general account of nonlocal symmetries in symmetric space models
and their relation to the AdS/CFT correspondence. In particular, we study a
master symmetry which generates the spectral parameter and acts as a
level-raising operator on the classical Yangian generators. The master symmetry
extends to an infinite tower of symmetries with nonlocal Casimir elements as
associated conserved charges. We discuss the algebraic properties of these
symmetries and establish their role in explaining the recently observed
one-parameter deformation of holographic Wilson loops. Finally, we provide a
numerical framework, in which discretized minimal surfaces and their master
symmetry deformation can be calculated.


title: On the rotation of nuclear star clusters formed by cluster-inspirals

abstract:
  Nuclear Star Clusters (NSCs) are commonly observed in the centres of most
galactic nuclei, including our own Milky Way. While their study can reveal
important information about the build-up of the innermost regions of galaxies,
the physical processes that regulate their formation are still poorly
understood. NSCs might have been formed through gas infall and subsequent in
situ star formation, and/or through the infall and merging of multiple star
clusters into the centre of the galaxy. Here, we investigate the viability of
the latter, by studying direct N-body simulations of inspiralling clusters to
the centre of a Milky-Way-like nuclear bulge that hosts a massive black hole.
We find that the NSC that forms through this process can show both
morphological and kinematical properties that make it comparable with
observations of the Milky Way NSC, including significant rotation- a fact that
has been so far attributed mainly to gas infall. We explore its kinematic
evolution, to see if and how the merger history can imprint fossil records on
its dynamical structure. Moreover, we study the effect of stellar foreground
contamination in the line-of-sight kinematics of the NSC. Our study shows that
no fine tuning of the orientation of the infalling globular clusters is
necessary to result in a rotating NSC. We suggest that cluster-inspiral is a
viable mechanism for the formation of rotating NSCs.


title:
The Rest-Frame Optical Morphology of Emission Line Galaxies at 2 < z <
  3: Evidence for Inside-Out Formation in Low-Mass Galaxies

abstract:
  We compare the rest-frame ultraviolet and rest-frame optical morphologies of
2 < z < 3 star-forming galaxies in the GOODS-S field using Hubble Space
Telescope WFC3 and ACS images from the CANDELS, GOODS, and ERS programs. We
show that the distribution of sizes and concentrations for 1.90 < z < 2.35
galaxies selected via their rest-frame optical emission-lines are statistically
indistinguishable from those of Lyman-alpha emitting systems found at z ~ 2.1
and z ~ 3.1. We also show that the z > 2 star-forming systems of all sizes and
masses become smaller and more compact as one shifts the observing window from
the UV to the optical. We argue that this offset is due to inside-out galaxy
formation over the first ~ 2 Gyr of cosmic time.


title: A Characteristic Scale for Cold Gas

abstract:
  We find that clouds of optically-thin, pressure-confined gas are prone to
fragmentation as they cool below $\sim10^6$ K. This fragmentation follows the
lengthscale $\sim{c}_{\text{s}}\,t_{\text{cool}}$, ultimately reaching very
small scales ($\sim{0.1} \text{pc}/n$) as they reach the temperature $\sim10^4$
K at which hydrogen recombines. While this lengthscale depends on the ambient
pressure confining the clouds, we find that the column density through an
individual fragment $N_{\text{cloudlet}}\sim10^{17} \text{cm}^{-3}$ is
essentially independent of environment; this column density represents a
characteristic scale for atomic gas at $10^4$ K. We therefore suggest that
"clouds" of cold, atomic gas may in fact have the structure of a mist or a fog,
composed of tiny fragments dispersed throughout the ambient medium. We show
that this scale emerges in hydrodynamic simulations, and that the corresponding
increase in the surface area may imply rapid entrainment of cold gas. We also
apply it to a number of observational puzzles, including the large covering
fraction of diffuse gas in galaxy halos, the broad line widths seen in quasar
and AGN spectra, and the entrainment of cold gas in galactic winds. While our
simulations make a number of assumptions and thus have associated
uncertainties, we show that this characteristic scale is consistent with a
number of observations, across a wide range of astrophysical environments. We
discuss future steps for testing, improving, and extending our model.


title:
Statistical properties of damped Lyman-alpha systems from Sloan Digital
  Sky Survey DR12

abstract:
  We present new estimates for the statistical properties of damped
Lyman-$\alpha$ absorbers (DLAs). We compute the column density distribution
function at $z>2$, the line density, $\mathrm{d}N/\mathrm{d}X$, and the neutral
hydrogen density, $\Omega_\mathrm{DLA}$. Our estimates are derived from the DLA
catalogue of Garnett 2016, which uses the SDSS-III DR12 quasar spectroscopic
survey. This catalogue provides a probability that a given spectrum contains a
DLA, allowing us to use even the noisiest data without biasing our results and
thus substantially increase our sample size. We measure a non-zero column
density distribution function at $95\%$ confidence for all column densities
$N_\mathrm{HI} < 5\times 10^{22}$ cm$^{-2}$. We make the first measurements
from SDSS of $\mathrm{d}N/\mathrm{d}X$ and $\Omega_\mathrm{DLA}$ at $z>4$. We
show that our results are insensitive to the signal-to-noise ratio of the
spectra, but that there is a residual dependence on quasar redshift for
$z<2.5$, which may be due to remaining systematics in our analysis.


title:
Transverse Force on Transversely Polarized Quarks in Longitudinally
  Polarized Nucleons

abstract:
  We study the semi-classical interpretation of the $x^3$ and $x^4$ moments of
twist-3 parton distribution functions (PDFs). While no semi-classical
interpretation for the higher moments of $g_T(x)$ and $e(x)$ was find, the
$x^3$ moment of the chirally odd spin-dependent twist-3 PDF $h_L^3(x)$ can be
related to the longitudinal gradient of the transverse force on transversely
polarized quarks in longitudinally polarized nucleons in a DIS experiment. We
discuss how this result relates to the torque acting on a quark in the same
experiment. This has further implications for comparisons between tha
Jaffe-Manohar and the Ji decompositions of the nucleon spin.


title:
Radio Properties of the BAT AGN: the FIR-Radio Relation, the Fundamental
  Plane, and the Main Sequence of Star Formation

abstract:
  We have conducted 22 GHz 1" JVLA imaging of 70 radio-quiet AGN from the
Swift-BAT survey. We find radio cores in all but three objects. The radio
morphologies of the sample fall into three groups: compact and core-dominated,
extended, and jet-like. We spatially decompose each image into core flux and
extended flux, and compare the extended radio emission to that predicted from
previous Herschel observations using the canonical FIR-radio relation. After
removing the AGN contribution to the FIR and radio flux densities, we find that
the relation holds remarkably well despite the potentially different star
formation physics in the circumnuclear environment. We also compare our core
radio flux densities with predictions of coronal models and scale-invariant jet
models for the origin of radio emission in radio-quiet AGN, and find general
consistency with both models. However, we find that the $L_{\mathrm{R}} /
L_{\mathrm{X}}$ relation does not distinguish between star formation and
non-relativistic AGN-driven outflows as the origin of radio emission in
radio-quiet AGN. Finally, we examine where objects with different radio
morphologies fall in relation to the main sequence of star formation, and
conclude that those AGN that fall below the main sequence, as X-ray selected
AGN have been found to do, have core-dominated or jet-like 22 GHz morphologies.


title: Distortion estimates for barycentric coordinates on Riemannian simplices

abstract:
  We define barycentric coordinates on a Riemannian manifold using Karcher's
center of mass technique applied to point masses for n+1 sufficiently close
points, determining an n-dimensional Riemannian simplex defined as a "Karcher
simplex." Specifically, a set of weights is mapped to the Riemannian center of
mass for the corresponding point measures on the manifold with the given
weights. If the points lie sufficiently close and in general position, this map
is smooth and injective, giving a coordinate chart. We are then able to compute
first and second derivative estimates of the coordinate chart. These estimates
allow us to compare the Riemannian metric with the Euclidean metric induced on
a simplex with edge lengths determined by the distances between the points. We
show that these metrics differ by an error that shrinks quadratically with the
maximum edge length. With such estimates, one can deduce convergence results
for finite element approximations of problems on Riemannian manifolds.


title:
Planck's Dusty GEMS. II. Extended [CII] emission and absorption in the
  Garnet at z=3.4 seen with ALMA

abstract:
  We present spatially resolved ALMA [CII] observations of the bright (flux
density S=400 mJy at 350 microns), gravitationally lensed, starburst galaxy
PLCK G045.1+61.1 at z=3.427, the "Garnet". This source is part of our set of
"Planck's Dusty GEMS", discovered with the Planck's all-sky survey. Two
emission-line clouds with a relative velocity offset of ~600 km/s extend
towards north-east and south-west, respectively, of a small, intensely
star-forming clump with a star-formation intensity of 220 Msun/yr/kpc^2, akin
to maximal starbursts. [CII] is also seen in absorption, with a redshift of
+350 km/s relative to the brightest CO component. [CII] absorption has
previously only been found in the Milky Way along sightlines toward bright
high-mass star-forming regions, and this is the first detection in another
galaxy. Similar to Galactic environments, the [CII] absorption feature is
associated with [CI] emission, implying that this is diffuse gas shielded from
the UV radiation of the clump, and likely at large distances from the clump.
Since absorption can only be seen in front of a continuum source, the gas in
this structure can definitely be attributed to gas flowing towards the clump.
The absorber could be part of a cosmic filament or merger debris being accreted
onto the galaxy. We discuss our results also in light of the on-going debate of
the origin of the [CII] deficit in dusty star-forming galaxies.


title:
Born Dry in the Photo-Evaporation Desert: Kepler's Ultra-Short-Period
  Planets Formed Water-Poor

abstract:
  Recent surveys have uncovered an exciting new population of
ultra-short-period (USP) planets with orbital periods less than a day. These
planets typically have radii <1.5 Earth radii, indicating that they likely have
rocky compositions. This stands in contrast to the overall distribution of
planets out to ~100 days, which is dominated by low-density sub-Neptunes above
2 Earth radii, which must have gaseous envelopes to explain their size.
However, on ultra-short-period orbits, planets are bombarded by intense levels
of photo-ionizing radiation and consequently gaseous sub-Neptunes are extremely
vulnerable to losing their envelopes to atmospheric photo-evaporation. Using
models of planet evolution, I show that the rocky USP planets can easily be
produced as the evaporated remnants of sub-Neptunes with H/He envelopes and
that we can therefore understand the observed dearth of USP sub-Neptunes as a
natural consequence of photo-evaporation. Critically however, planets on USP
orbits could often retain their envelopes if they formed with very
high-metallicity water dominated envelopes. Such water-rich planets would
commonly be >2 Earth radii today, which is inconsistent with the observed
evaporation desert, indicating that most USP planets likely formed from
water-poor material within the snow-line. Finally, I examine the special case
of 55 Cancri e and its possible composition in the light of recent
observations, and discuss the prospects for further characterizing this
population with future observations.


title:
Nematic fluctuations balancing the zoo of phases in half-filled quantum
  Hall systems

abstract:
  Half-filled Landau levels form a zoo of strongly correlated phases. These
include non-Fermi liquids (NFL), fractional quantum Hall (FQH) states, nematic
phases, and FQH nematic phases. This diversity poses the question: what keeps
the balance between the seemingly unrelated phases? The answer is elusive
because the Halperin-Lee-Read (HLR) description that offers a natural departure
point is inherent strongly coupled. But the observed nematic phases suggest
nematic fluctuations play an important role. To study this possibility, we
apply a recently formulated controlled double expansion approach in large-$N$
composite fermion flavors and small $\epsilon$ non-analytic bosonic action to
the case with both gauge and nematic boson fluctuations. In the vicinity of a
nematic quantum critical line (NQCL), we find that depending on the amount of
screening of the gauge- and nematic-mediated interactions controlled by
$\epsilon$'s, the RG flow points to all four mentioned correlated phases. When
pairing preempts the nematic phase, NFL behavior is possible at temperatures
above the pairing transition. We conclude by discussing measurements at low
tilt angles which could reveal the stabilization of the FQH phase by nematic
fluctuations.


title: Irreversibility and correlations in coupled quantum oscillators

abstract:
  We investigate the link between the irreversibility generated by a stationary
dissipative process and the correlations established within a composite quantum
system. We provide two equivalent expressions for the entropy generated in the
non-equilibrium steady state of coupled quantum harmonic oscillators that allow
for a simple interpretation of the onset of irreversibility. We then unveil a
quantitative relation between the entropy production rate and correlations,
both total and quantum, built between the two oscillators. In the
small-coupling limit, the entropy production rate is shown to be proportional
to both the mutual information and the quantum correlations. We apply our
results to the analysis of the optomechanical interaction between a
nano-mechanical resonator and a cavity field, and show that the behavior of the
entropy production captures the peculiar features of the model, such as
sideband cooling and amplification.


title:
Herschel Observations and Updated Spectral Energy Distributions of Five
  Sunlike Stars with Debris Disks

abstract:
  Observations from the Herschel Space Observatory have more than doubled the
number of wide debris disks orbiting Sunlike stars to include over 30 systems
with R > 100 AU. Here we present new Herschel PACS and re-analyzed Spitzer MIPS
photometry of five Sunlike stars with wide debris disks, from Kuiper belt size
to R > 150 AU. The disk surrounding HD 105211 is well resolved, with an angular
extent of >14" along the major axis, and the disks of HD 33636, HD 50554, and
HD 52265 are extended beyond the PACS PSF size (50% of energy enclosed within
radius 4.23"). HD 105211 also has a 24-micron infrared excess that was
previously overlooked because of a poorly constrained photospheric model.
Archival Spitzer IRS observations indicate that the disks have small grains of
minimum radius ~3 microns, though the minimum grain gradius is larger than the
radiation pressure blowout size in all systems. If modeled as
single-temperature blackbodies, the disk temperatures would all be <60 K. Our
radiative transfer models predict actual disk radii approximately twice the
radius of model blackbody disks. We find that the Herschel photometry traces
dust near the source population of planetesimals. The disk luminosities are in
the range 0.00002 <= L/L* <= 0.0002, consistent with collisions in icy
planetesimal belts stirred by Pluto-size dwarf planets.


title:
IFU spectroscopy of 10 early-type galactic nuclei - IV. Properties of
  the circumnuclear stellar kinematics

abstract:
  The study of stellar kinematic properties may provide hints on the formation
and evolution of elliptical and lenticular galaxies. Although most previous
studies have focused on the large scale of these galaxies, their central
regions (scales of $\sim$ 100 pc) may contain important clues about their
structure, such as kinematically decoupled cores. This is the fourth paper on a
sample of 10 massive ($\sigma$ $>$ 200 km s$^{-1}$) and nearby ($d$ $<$ 31 Mpc)
early-type galaxies, observed with the integral field unit of the Gemini South
Multi Object Spectrograph. Here, we analyse the properties of the stellar
kinematics in the circumnuclear region. We fitted the line-of-sight velocity
distribution with a Gauss-Hermite function. In seven galaxies of the sample, we
detected a rotation pattern in their radial velocity maps that are
anti-correlated with $h_3$. We interpret this as stellar structures in rotation
embedded in the bulges of the objects. Comparing the stellar kinematic results
with the PCA Tomography results and also with the gas kinematic results of IC
5181, it seems that this object may have a non-axisymmetric potential at its
centre. The velocity dispersion maps of four objects have a nuclear peak, which
must correspond, in part, to unresolved stellar rotation. In NGC 1404, we
detected a kinematic decoupled core with an extension of $\sim$ 200 pc. This
galaxy also has a $\sigma$-drop in the centre, which may be related to both
stellar components in counterrotation or with a kinematically cold star-forming
region.


title:
On the Algorithmic Significance and Analysis of the Method of DaYan
  Deriving One

abstract:
  Modulo inverse is an important arithmetic operation. Many famous algorithms
in public key cryptography require to compute modulo inverse. It is argued that
the method of DaYan deriving one of Jiushao Qin provides the most concise and
transparent way of computing modulo inverse. Based on the rule of taking the
least positive remainder in division, this paper presents a more precise
algorithmic description of the method of DaYan deriving one to reflect Qin's
original idea. Our form of the algorithm is straightforward and different from
the ones in the literature. Some additional information can be revealed easily
from the process of DaYan deriving one, e.g., the invariance property of the
permanent of the state, natural connection to continued fractions. Comparison
of Qin'a algorithm and the modern form of the Extended Euclidean algorithm is
also given. Since DaYan deriving one is the key technical ingredient of Jiushao
Qin's DaYan aggregation method (aka the Chinese Remainder Theorem), we include
some explanation to the latter as well.


title:
Supernova rates from the SUDARE VST-Omegacam search II. Rates in a
  galaxy sample

abstract:
  This is the second paper of a series in which we present measurements of the
Supernova (SN) rates from the SUDARE survey. In this paper, we study the trend
of the SN rates with the intrinsic colours, the star formation activity and the
mass of the parent galaxies. We have considered a sample of about 130000
galaxies and a SN sample of about 50 events. We found that the SN Ia rate per
unit mass is higher by a factor of six in the star-forming galaxies with
respect to the passive galaxies. The SN Ia rate per unit mass is also higher in
the less massive galaxies that are also younger. These results suggest a
distribution of the delay times (DTD) less populated at long delay times than
at short delays. The CC SN rate per unit mass is proportional to both the sSFR
and the galaxy mass. The trends of the Type Ia and CC SN rates as a function of
the sSFR and the galaxy mass that we observed from SUDARE data are in agreement
with literature results at different redshifts. The expected number of SNe Ia
is in agreement with the observed one for all four DTD models considered both
in passive and star-forming galaxies so we can not discriminate between
different progenitor scenarios. The expected number of CC SNe is higher than
the observed one, suggesting a higher limit for the minimum progenitor mass. We
also compare the expected and observed trends of the SN Ia rate with the
intrinsic U - J colour of the parent galaxy, assumed as a tracer of the age
distribution. While the slope of the relation between the SN Ia rate and the U
- J color in star-forming galaxies can be reproduced well by all four DTD
models considered, only the steepest of them is able to account for the rates
and colour in star-forming and passive galaxies with the same value of the SN
Ia production efficiency.


title:
An optically detected magnetic resonance spectrometer with tunable laser
  excitation and wavelength resolved infrared detection

abstract:
  We present the development and performance of an optically detected magnetic
resonance (ODMR) spectrometer. The spectrometer represents advances over
similar instruments in three areas: i) the exciting light is a tunable laser
source which covers much of the visible light range, ii) the optical signal is
analyzed with a spectrograph, iii) the emitted light is detected in the
near-infrared domain. The need to perform ODMR experiments on single-walled
carbon nanotubes motivated the present development and we demonstrate the
utility of the spectrometer on this material. The performance of the
spectrometer is critically compared to similar instruments. The present
development opens the way to perform ODMR studies on various new materials such
as molecules and luminescent quantum dots where the emission is in the
near-infrared range and requires a well-defined excitation wavelength and
analysis of the scattered light.


title: A Tour of TensorFlow

abstract:
  Deep learning is a branch of artificial intelligence employing deep neural
network architectures that has significantly advanced the state-of-the-art in
computer vision, speech recognition, natural language processing and other
domains. In November 2015, Google released $\textit{TensorFlow}$, an open
source deep learning software library for defining, training and deploying
machine learning models. In this paper, we review TensorFlow and put it in
context of modern deep learning concepts and software. We discuss its basic
computational paradigms and distributed execution model, its programming
interface as well as accompanying visualization toolkits. We then compare
TensorFlow to alternative libraries such as Theano, Torch or Caffe on a
qualitative as well as quantitative basis and finally comment on observed
use-cases of TensorFlow in academia and industry.


title: Electromagnetic Effects on Cracking of Anisotropic Polytropes

abstract:
  In this paper, we study the electromagnetic effects on stability of
spherically symmetric anisotropic fluid distribution satisfying two polytropic
equations of state and construct the corresponding generalized Tolman
Oppenheimer Volkoff equations. We apply perturbations on matter variables via
polytropic constant as well as polytropic index and formulate the force
distribution function. It is found that the compact object is stable for
feasible choice of perturbed polytropic index in the presence of charge.


title: Counterion-Induced Swelling of Ionic Microgels

abstract:
  Ionic microgel particles, when dispersed in a solvent, swell to equilibrium
sizes that are governed by a balance between electrostatic and elastic forces.
Tuning of particle size by varying external stimuli, such as $p$H, salt
concentration, and temperature, has relevance for drug delivery, microfluidics,
and filtration. To model swelling of ionic microgels, we derive a statistical
mechanical theorem, which proves exact within the cell model, for the
electrostatic contribution to the osmotic pressure inside a permeable colloidal
macroion. Applying the theorem, we demonstrate how the distribution of
counterions within an ionic microgel determines the internal osmotic pressure.
By combining the electrostatic pressure, which we compute via both
Poisson-Boltzmann theory and molecular dynamics simulation, with the elastic
pressure, modeled via the Flory-Rehner theory of swollen polymer networks, we
show how deswelling of ionic microgels with increasing concentration of
particles can result from a redistribution of counterions that reduces
electrostatic pressure. A linearized approximation for the electrostatic
pressure, which proves remarkably accurate, provides physical insight and
greatly eases numerical calculations for practical applications. Comparing with
experiments, we explain why soft particles in deionized suspensions deswell
upon increasing concentration and why this effect may be suppressed at higher
ionic strength. The failure of the uniform ideal-gas approximation to
adequately account for counterion-induced deswelling below close packing of
microgels is attributed to neglect of spatial variation of the counterion
density profile and the electrostatic pressure of incompletely neutralized
macroions.


title:
Hidden Fermi-liquid charge transport in the antiferromagnetic phase of
  the electron-doped cuprates

abstract:
  Systematic analysis of the planar resistivity, Hall effect and cotangent of
the Hall angle for the electron-doped cuprates reveals underlying Fermi-liquid
behavior even deep in the antiferromagnetic part of the phase diagram. The
transport scattering rate exhibits a quadratic temperature dependence, and is
nearly independent of doping, compound and carrier type (electrons vs. holes),
and hence universal. Our analysis moreover indicates that the material-specific
resistivity upturn at low temperatures and low doping has the same origin in
both electron- and hole-doped cuprates.


title: 5G-ICN : Delivering ICN Services over 5G using Network Slicing

abstract:
  The challenging requirements of 5G--from both the applications and the
architecture perspectives--motivate the need to explore the feasibility of
delivering services over new network architectures. As 5G proposes
application-centric network slicing, which enables the use of new data planes
realizable over a programmable compute, storage, and transport infrastructure,
we consider Information-centric Networking (ICN) as a candidate network
architecture to realize 5G objectives. This can co-exist with end-to-end IP
services that are offered today. To this effect, we first propose a 5G-ICN
architecture and compare its benefits (i.e., innovative services offered by
leveraging ICN features) to current 3GPP-based mobile architectures. We then
introduce a general application-driven framework that emphasizes on the
flexibility afforded by Network Function Virtualization (NFV) and Software
Defined Networking (SDN) over which 5G-ICN can be realized. We specifically
focus on the issue of how mobility-as-a-service (MaaS) can be realized as a
5G-ICN slice, and give an in-depth overview on resource provisioning and
inter-dependencies and -coordinations among functional 5G-ICN slices to meet
the MaaS objectives.


title: The Physics of antineutrinos in DUNE and resolution of octant degeneracy

abstract:
  We study the capability of the DUNE experiment, which will be the first beam
based experiment with a wide band flux profile, to uncover the octant of the
leptonic mixing angle $\theta_{23}$ (i.e., $\theta_{23}$ is $< 45^\circ$ or
$>45^\circ$). In this work, we find that for the DUNE baseline of 1300 km, due
to enhanced matter effect, the neutrino and antineutrino probabilities are
different which creates a tension in the case of combined runs because of which
octant sensitivity also can come from disappearance channel. In view of this,
we study the physics of antineutrinos in DUNE and explore the role of
antineutrinos run that is required to resolve the octant degeneracy at a
certain confidence levels.


title: Nambu structures on Lie algebroids and their modular classes

abstract:
  We introduce the notion of the modular class of a Lie algebroid equipped with
a Nambu structure. In particular, we recover the modular class of a
Nambu-Poisson manifold $M$ with its Nambu tensor $\Lambda$ as the modular class
of the tangent Lie algebroid $TM$ with Nambu structure $\Lambda.$ We show that
many known properties of the modular class of a Nambu-Poisson manifold that of
a Lie algebropid extend to the setting of a Lie algebroid with Nambu structure.
Finally, we prove that for a large class of Nambu-Poisson manifolds considered
as tangent Lie algebroids with Nambu structures, the associated modular classes
are closely related to Evens-Lu-Weinstein modular classes of Lie algebroids.


title: Recursion-Theoretic Ranking and Compression

abstract:
  For which sets A does there exist a mapping, computed by a total or partial
recursive function, such that the mapping, when its domain is restricted to A,
is a 1-to-1, onto mapping to $\Sigma^*$? And for which sets A does there exist
such a mapping that respects the lexicographical ordering within A? Both cases
are types of perfect, minimal hash functions. The complexity-theoretic versions
of these notions are known as compression functions and ranking functions. The
present paper defines and studies the recursion-theoretic versions of
compression and ranking functions, and in particular studies the question of
which sets have, or lack, such functions. Thus, this is a case where, in
contrast to the usual direction of notion transferal, notions from complexity
theory are inspiring notions, and an investigation, in computability theory.
  We show that the rankable and compressible sets broadly populate the
1-truth-table degrees, and we prove that every nonempty coRE cylinder is
recursively compressible.


title:
VLT FORS2 comparative transmission spectroscopy: Detection of Na in the
  atmosphere of WASP-39b from the ground

abstract:
  We present transmission spectroscopy of the warm Saturn-mass exoplanet
WASP-39b made with the Very Large Telescope (VLT) FOcal Reducer and
Spectrograph (FORS2) across the wavelength range 411-810nm. The transit depth
is measured with a typical precision of 240 parts per million (ppm) in
wavelength bins of 10nm on a V = 12.1 magnitude star. We detect the sodium
absorption feature (3.2-sigma) and find evidence for potassium. The
ground-based transmission spectrum is consistent with Hubble Space Telescope
(HST) optical spectroscopy, strengthening the interpretation of WASP-39b having
a largely clear atmosphere. Our results demonstrate the great potential of the
recently upgraded FORS2 spectrograph for optical transmission spectroscopy,
obtaining HST-quality light curves from the ground.


title: Quantum-Secure Symmetric-Key Cryptography Based on Hidden Shifts

abstract:
  Recent results of Kaplan et al., building on previous work by Kuwakado and
Morii, have shown that a wide variety of classically-secure symmetric-key
cryptosystems can be completely broken by quantum chosen-plaintext attacks
(qCPA). In such an attack, the quantum adversary has the ability to query the
cryptographic functionality in superposition. The vulnerable cryptosystems
include the Even-Mansour block cipher, the three-round Feistel network, the
Encrypted-CBC-MAC, and many others. In this work, we study simple algebraic
adaptations of such schemes that replace $(\mathbb Z/2)^n$ addition with
operations over alternate finite groups--such as $\mathbb Z/{2^n}$--and provide
evidence that these adaptations are qCPA-secure. These adaptations furthermore
retain the classical security properties (and basic structural features)
enjoyed by the original schemes.
  We establish security by treating the (quantum) hardness of the well-studied
Hidden Shift problem as a basic cryptographic assumption. We observe that this
problem has a number of attractive features in this cryptographic context,
including random self-reducibility, hardness amplification, and--in many cases
of interest--a reduction from the "search version" to the "decisional version."
We then establish, under this assumption, the qCPA-security of several such
Hidden Shift adaptations of symmetric-key constructions. We show that a Hidden
Shift version of the Even-Mansour block cipher yields a quantum-secure
pseudorandom function, and that a Hidden Shift version of the Encrypted CBC-MAC
yields a collision-resistant hash function. Finally, we observe that such
adaptations frustrate the direct Simon's algorithm-based attacks in more
general circumstances, e.g., Feistel networks and slide attacks.


title: Data-centric Dynamic Partial Order Reduction

abstract:
  We present a new dynamic partial-order reduction method for stateless model
checking of concurrent programs. A common approach for exploring program
behaviors relies on enumerating the traces of the program, without storing the
visited states (aka stateless exploration). As the number of distinct traces
grows exponentially, dynamic partial-order reduction (DPOR) techniques have
been successfully used to partition the space of traces into equivalence
classes (Mazurkiewicz partitioning), with the goal of exploring only few
representative traces from each class.
  We introduce a new equivalence on traces under sequential consistency
semantics, which we call the observation equivalence. Two traces are
observationally equivalent if every read event observes the same write event in
both traces. While the traditional Mazurkiewicz equivalence is control-centric,
our new definition is data-centric. We show that our observation equivalence is
coarser than the Mazurkiewicz equivalence, and in many cases even exponentially
coarser. We devise a DPOR exploration of the trace space, called data-centric
DPOR, based on the observation equivalence. For acyclic architectures, our
algorithm is guaranteed to explore exactly one representative trace from each
observation class, while spending polynomial time per class. Hence, our
algorithm is optimal wrt the observation equivalence, and in several cases
explores exponentially fewer traces than any enumerative method based on the
Mazurkiewicz equivalence. For cyclic architectures, we consider an equivalence
between traces which is finer than the observation equivalence; but coarser
than the Mazurkiewicz equivalence, and in some cases is exponentially coarser.
Our data-centric DPOR algorithm remains optimal under this trace equivalence.