title: The decay of Hopf solitons in the Skyrme model

abstract:
  It is understood that the Skyrme model has a topologically interesting
baryonic excitation which can model nuclei. So far no stable knotted solutions,
of the Skyrme model, have been found. Here we investigate the dynamics of Hopf
solitons decaying to the vacuum solution in the Skyrme model. In doing this we
develop a matrix-free numerical method to identify the minimum eigenvalue of
the Hessian of the corresponding energy functional. We also show that as the
Hopf solitons decay, they emit a cloud of isospinning radiation.


title: Stability of the graviton Bose-Einstein condensate in the brane-world

abstract:
  We consider a solution of the effective four-dimensional Einstein equations,
obtained from the general relativistic Schwarzschild metric through the
principle of Minimal Geometric Deformation (MGD). Since the brane tension can,
in general, introduce new singularities on a relativistic E\"otv\"os brane
model in the MGD framework, we require the absence of observed singularities,
in order to constrain the brane tension. We then study the corresponding
Bose-Einstein condensate (BEC) gravitational system and determine the critical
stability region of BEC MGD stellar configurations. Finally, the critical
stellar densities are shown to be related with critical points of the
information entropy.


title: The mean light curves of the Mira-type stars in the H- and K-bands

abstract:
  For nine Mira-type stars (o Cet, R Leo, S Car, U Her, X Oph, R Aql, RR Aql, S
Ori, S Scl,) and one semi-regular star (L2 Pup), the mean light curves have
been obtained. The initial values of the brightness (observations) were fitted
by a trigonometric polynomial of the statistically optimal order. The Fourier
coefficients and the additional parameters (degree of the trigonometric
polynomial, amplitude of the brightness, the maximal slope of ascending and
descending branch, semi-amplitudes and initial epochs for the brightness
maximum (minimum magnitude) of each harmonic contribution, etc., were given in
the tables reported earlier (Kudashkina, 2015). In this study, we have received
several interesting correlations between these parameters in the bands H and K.
It was particularly noted the anomalous position on the figures of the star X
Oph. The mean light curves of the investigated stars are commonly symmetric in
the near infrared region (H and K).


title: The Special Aronszajn Tree Property

abstract:
  Assuming the existence of a proper class of supercompact cardinals, we force
that for every regular cardinal $\kappa$, there are $\kappa^+$-Aronszajn trees
and all such trees are special.


title:
Unexpected distribution of $\nu1f_{7/2}$ strength in the calcium
  isotopes at $N$=30

abstract:
  The calcium isotopes have emerged as an important testing ground for new
microscopically derived shell-model interactions, and a great deal of focus has
been directed toward this region. We investigate the relative spectroscopic
strengths associated with $1f_{7/2}$ neutron hole states in $^{47, 49}$Ca
following one-neutron knockout reactions from $^{48,50}$Ca. The observed
reduction of strength populating the lowest 7/2$^{-}_{1}$ state in $^{49}$Ca,
as compared to $^{47}$Ca, is consistent with the description given by
shell-model calculations based on two- and three-nucleon forces in the neutron
$pf$ model space, implying a fragmentation of the $l$=3 strength to
higher-lying states. The experimental result is inconsistent with both the
GXPF1 interaction routinely used in this region of the nuclear chart and with
microscopic calculations in an extended model space including the $\nu1g_{9/2}$
orbital.


title:
The spectrum and mass anomalous dimension of SU(2) adjoint QCD with two
  Dirac flavours

abstract:
  In this work we present the results of our investigation of SU(2) gauge
theory with two Dirac fermions in the adjoint representation, also known as
Minimal Walking Technicolour. We have done numerical lattice simulations of
this theory at two different values of the gauge coupling and several fermion
masses. Our results include the particle spectrum and the mass anomalous
dimension. The spectrum contains so far unconsidered states, a fermion-gluon
state and flavour singlet mesons. The mass anomalous dimension is determined
from the scaling of the masses and the mode number. The remnant dependence of
the universal mass ratios and mass anomalous dimension on the gauge coupling
indicates the relevance of scaling corrections.


title:
An important role of temperature dependent scattering time in
  understanding the high temperature thermoelectric behavior of strongly
  correlated system: La$_{0.75}$Ba$_{0.25}$CoO$_{3}$

abstract:
  In the present work, we have reported the temperature dependent thermopower
($\alpha$) behavior of La$_{0.75}$Ba$_{0.25}$CoO$_{3}$ compound in the
temperature range 300-600 K. Using the Heikes formula, the estimated value of
$\alpha$ corresponding to high-spin configuration of Co$^{3+}$ and Co$^{4+}$
ions is found to be $\sim$$16$ $\mu$V/K, which is close to the experimental
value, $\sim$13 $\mu$V/K, observed at $\sim$600 K. The temperature dependent TE
behavior of the compound is studied by combining the WIEN2K and BoltzTrap code.
The self consistency field calculations show that the compound have
ferromagnetic ground state structure. The electronic structure calculations
give half metallic characteristic with a small gap of $\sim$50 meV for down
spin channel. The large and positive value for down spin channel is obtained
due to the unique band structure shown by this spin channel. The temperature
dependent relaxation time for both the spin-channel charge carriers is
considered to study the thermopower data in temperature range 300-600 K. An
almost linear values of $\tau_{up}$ and a non-linear values of $\tau_{dn}$ are
taken into account for evaluation of $\alpha$. By taking the temperature
dependent values of relaxation time for both the spin channels, the calculated
values of $\alpha$ using two current model are found to be in good agreement
with experimental values in the temperature range 300-600 K. At 300 K, the
calculated value of electrical conductivity by using the same value of
relaxation time, i.e. 0.1 $\times $10$^{-14}$ seconds for spin-up and 0.66
$\times $10$^{-14}$ seconds for spin-dn channel, is found to be equal to the
experimentally reported value.


title:
A new algorithm for identity verification based on the analysis of a
  handwritten dynamic signature

abstract:
  Identity verification based on authenticity assessment of a handwritten
signature is an important issue in biometrics. There are many effective methods
for signature verification taking into account dynamics of a signing process.
Methods based on partitioning take a very important place among them. In this
paper we propose a new approach to signature partitioning. Its most important
feature is the possibility of selecting and processing of hybrid partitions in
order to increase a precision of the test signature analysis. Partitions are
formed by a combination of vertical and horizontal sections of the signature.
Vertical sections correspond to the initial, middle, and final time moments of
the signing process. In turn, horizontal sections correspond to the signature
areas associated with high and low pen velocity and high and low pen pressure
on the surface of a graphics tablet. Our previous research on vertical and
horizontal sections of the dynamic signature (created independently) led us to
develop the algorithm presented in this paper. Selection of sections, among
others, allows us to define the stability of the signing process in the
partitions, promoting signature areas of greater stability (and vice versa). In
the test of the proposed method two databases were used: public MCYT-100 and
paid BioSecure.


title:
Supercontinuum generation with bright and dark solitons in optical
  fibers

abstract:
  We study numerically and experimentally supercontinuum generation in optical
fibers with dark and bright solitons simultaneously contributing into the
spectral broadening and dispersive wave generation. We report a novel type of
weak trapped radiation arising due to interaction of bright solitons with the
dark soliton background. This radiation expresses itself as two pulses with the
continuously shifting spectra constituting the short and long wavelength limits
of the continuum. Our theoretical and experimental results are in good
agreement.


title: Revisiting the EC/CMB model for extragalactic large scale jets

abstract:
  One of the most outstanding results of the Chandra X-ray Observatory was the
discovery that AGN jets are bright X-ray emitters on very large scales, up to
hundreds of kpc. Of these, the powerful and beamed jets of Flat Spectrum Radio
Quasars are particularly interesting, as the X-ray emission cannot be explained
by an extrapolation of the lower frequency synchrotron spectrum. Instead, the
most common model invokes inverse Compton scattering of photons of the Cosmic
Microwave Background (EC/CMB) as the mechanism responsible for the high energy
emission. The EC/CMB model has recently come under criticism, particularly
because it should predict a significant steady flux in the MeV-GeV band which
has not been detected by the Fermi/LAT telescope for two of the best studied
jets (PKS 0637-752 and 3C273). In this work we revisit some aspects of the
EC/CMB model and show that electron cooling plays an important part in shaping
the spectrum. This can solve the overproduction of gamma-rays by suppressing
the high energy end of the emitting particle population. Furthermore, we show
that cooling in the EC/CMB model predicts a new class of extended jets that are
bright in X-rays but silent in the radio and optical bands. These jets are more
likely to lie at intermediate redshifts, and would have been missed in all
previous X-ray surveys due to selection effects.


title:
High Precision Full Stokes Spectropolarimetry of the Sun as a
  star-Instrument design aspects

abstract:
  The magnetic field plays a major role in governing the dynamics of the sun.
Many interesting features like sunspots, flares, prominences, and Coronal Mass
Ejections (CMEs) occur on its surface due to the dynamics associated with the
magnetic fields. The magnetic activity exhibits spatial scales ranging from
very fine scale (below the resolution limit of the current largest telescope)
to large scale such as sunspots, active regions and the spatial scales as large
as the sun itself. While the major efforts in building large telescopes is
going on towards the goal of resolving smallest structure possible we propose
here to measure the magnetic field on the global scale. For this purpose we
propose an instrument to carryout high precision and high accurate
spectropolarimetry of sun-as-a-star. In this thesis, we explore various
instrumental design aspects that are necessary to make such observations. As
part of the design consideration we have analysed a major noise source i.e.
seeing induced cross-talk through simulation as well as using the measured
scintillation data. Further, we have analysed full disk Stokes images from
SOLIS/VSM and SDO/HMI for the purpose of getting a rough idea on the disk
averaged Stokes signal level. The instrument design aspects are mainly
constrained by the need to modulate the light before it enters the telescope
and image the full sun as a point source. Modulating the light before it enters
the telescope has the advantage of completely avoiding the instrumental
polarization which will enable us to carry out high accurate polarimetric
measurements. We have explored in this thesis various concepts of polarization
modulator and spectral discriminator and worked out their suitability for the
purpose of carrying out high precision and high accurate spectropolarimetry of
sun-as-a-star at high spectral resolution.


title: Violent relaxation in quantum fluids with long-range interactions

abstract:
  Violent relaxation is a process that occurs in systems with long-range
interactions. It has the peculiar feature of dramatically amplifying small
perturbations, and rather than driving the system to equilibrium it instead
leads to slowly evolving configurations known as quasi-stationary states that
fall outside the standard paradigm of statistical mechanics. Violent relaxation
was originally identified in gravity-driven stellar dynamics; here we extend
the theory into the quantum regime by developing a quantum version of the
Hamiltonian Mean Field (HMF) model which exemplifies many of the generic
properties of long-range interacting systems. The HMF model can either be
viewed as describing particles interacting via a cosine potential, or
equivalently as the kinetic XY-model with infinite range interactions, and its
quantum fluid dynamics can be obtained from a generalized Gross-Pitaevskii
equation. We show that singular caustics that form during violent relaxation
are regulated by interference effects in a universal way described by Thom's
catastrophe theory applied to waves and this leads to emergent length and time
scales not present in the classical problem. In the deep quantum regime we find
that violent relaxation is suppressed altogether by quantum zero-point motion.
Our results are relevant to laboratory studies of self-organization in cold
atomic gases with long-range interactions.


title:
A Connection between the Riemann Hypothesis and Uniqueness of the
  Riemann zeta function

abstract:
  In this paper, we give a connection between the Riemann hypothesis and
uniqueness of the Riemann zeta function and an analogue for L-functions.


title: An Exact Solution of the Fokker-Planck Equation for Isotropic Scattering

abstract:
  An analytic solution for a Fokker-Planck equation that describes propagation
of energetic particles through a scattering medium is obtained. The solution is
found in terms of an infinite series of mixed moments of particle distribution.
The spatial dispersion of a particle cloud released at t=0 evolves through
three phases, ballistic (t<Tc), transdiffusive (t~Tc) and diffusive (t>>Tc),
where Tc is the collision time.The ballistic phase is characterized by a
decelerating expansion of the initial point source in form of a "box"
distribution with thickening walls. The next, transdiffusive phase is marked by
the box walls thickened to its size and a noticeable slow down of expansion.
Finally, the evolution enters the conventional diffusion phase.


title:
Caching in the Sky: Proactive Deployment of Cache-Enabled Unmanned
  Aerial Vehicles for Optimized Quality-of-Experience

abstract:
  In this paper, the problem of proactive deployment of cache-enabled unmanned
aerial vehicles (UAVs) for optimizing the quality-of-experience (QoE) of
wireless devices in a cloud radio access network (CRAN) is studied. In the
considered model, the network can leverage human-centric information such as
users' visited locations, requested contents, gender, job, and device type to
predict the content request distribution and mobility pattern of each user.
Then, given these behavior predictions, the proposed approach seeks to find the
user-UAV associations, the optimal UAVs' locations, and the contents to cache
at UAVs. This problem is formulated as an optimization problem whose goal is to
maximize the users' QoE while minimizing the transmit power used by the UAVs.
To solve this problem, a novel algorithm based on the machine learning
framework of conceptor-based echo state networks (ESNs) is proposed. Using
ESNs, the network can effectively predict each user's content request
distribution and its mobility pattern when limited information on the states of
users and the network is available. Based on the predictions of the users'
content request distribution and their mobility patterns, we derive the optimal
user-UAV association, optimal locations of the UAVs as well as the content to
cache at UAVs. Simulation results using real pedestrian mobility patterns from
BUPT and actual content transmission data from Youku show that the proposed
algorithm can yield 40% and 61% gains, respectively, in terms of the average
transmit power and the percentage of the users with satisfied QoE compared to a
benchmark algorithm without caching and a benchmark solution without UAVs.


title:
Learning How to Communicate in the Internet of Things: Finite Resources
  and Heterogeneity

abstract:
  For a seamless deployment of the Internet of Things (IoT), there is a need
for self-organizing solutions to overcome key IoT challenges that include data
processing, resource management, coexistence with existing wireless networks,
and improved IoT-wide event detection. One of the most promising solutions to
address these challenges is via the use of innovative learning frameworks that
will enable the IoT devices to operate autonomously in a dynamic environment.
However, developing learning mechanisms for the IoT requires coping with unique
IoT properties in terms of resource constraints, heterogeneity, and strict
quality-of-service requirements. In this paper, a number of emerging learning
frameworks suitable for IoT applications are presented. In particular, the
advantages, limitations, IoT applications, and key results pertaining to
machine learning, sequential learning, and reinforcement learning are studied.
For each type of learning, the computational complexity, required information,
and learning performance are discussed. Then, to handle the heterogeneity of
the IoT, a new framework based on the powerful tools of cognitive hierarchy
theory is introduced. This framework is shown to efficiently capture the
different IoT device types and varying levels of available resources among the
IoT devices. In particular, the different resource capabilities of IoT devices
are mapped to different levels of rationality in cognitive hierarchy theory,
thus enabling the IoT devices to use different learning frameworks depending on
their available resources. Finally, key results on the use of cognitive
hierarchy theory in the IoT are presented.


title:
Validation of Twitter opinion trends with national polling aggregates:
  Hillary Clinton vs Donald Trump

abstract:
  Measuring and forecasting opinion trends from real-time social media is a
long-standing goal of big-data analytics. Despite its importance, there has
been no conclusive scientific evidence so far that social media activity can
capture the opinion of the general population. Here we develop a method to
infer the opinion of Twitter users regarding the candidates of the 2016 US
Presidential Election by using a combination of statistical physics of complex
networks and machine learning based on hashtags co-occurrence to develop an
in-domain training set approaching 1 million tweets. We investigate the social
networks formed by the interactions among millions of Twitter users and infer
the support of each user to the presidential candidates. The resulting Twitter
trends follow the New York Times National Polling Average, which represents an
aggregate of hundreds of independent traditional polls, with remarkable
accuracy. Moreover, the Twitter opinion trend precedes the aggregated NYT polls
by 10 days, showing that Twitter can be an early signal of global opinion
trends. Our analytics unleash the power of Twitter to uncover social trends
from elections, brands to political movements, and at a fraction of the cost of
national polls.


title: Neural Structural Correspondence Learning for Domain Adaptation

abstract:
  Domain adaptation, adapting models from domains rich in labeled training data
to domains poor in such data, is a fundamental NLP challenge. We introduce a
neural network model that marries together ideas from two prominent strands of
research on domain adaptation through representation learning: structural
correspondence learning (SCL, (Blitzer et al., 2006)) and autoencoder neural
networks. Particularly, our model is a three-layer neural network that learns
to encode the nonpivot features of an input example into a low-dimensional
representation, so that the existence of pivot features (features that are
prominent in both domains and convey useful information for the NLP task) in
the example can be decoded from that representation. The low-dimensional
representation is then employed in a learning algorithm for the task. Moreover,
we show how to inject pre-trained word embeddings into our model in order to
improve generalization across examples with similar pivot features. On the task
of cross-domain product sentiment classification (Blitzer et al., 2007),
consisting of 12 domain pairs, our model outperforms both the SCL and the
marginalized stacked denoising autoencoder (MSDA, (Chen et al., 2012)) methods
by 3.77% and 2.17% respectively, on average across domain pairs.


title:
Level set formulation of two-dimensional Lagrangian vortex detection
  methods

abstract:
  We propose here the use of the variational level set methodology to capture
Lagrangian vortex boundaries in 2D unsteady velocity fields. This method
reformulates earlier approaches that seek material vortex boundaries as
extremum solutions of variational problems. We demonstrate the performance of
this technique for two different variational formulations built upon different
notions of coherence. The first formulation uses an energy functional that
penalizes the deviation of a closed material line from piecewise uniform
stretching [Haller and Beron-Vera, J. Fluid Mech. 731, R4 (2013)]. The second
energy function is derived for a graph-based approach to vortex boundary
detection [Hadjighasem et al., Phys. Rev. E 93, 063107 (2016)]. Our level-set
formulation captures an a priori unknown number of vortices simultaneously at
relatively low computational cost. We illustrate the approach by identifying
vortices from different coherence principles in several examples.


title: Gravitomagnetic dynamical friction

abstract:
  A supermassive black hole moving through a field of stars will
gravitationally scatter the stars, inducing a backreaction force on the black
hole known as dynamical friction. In Newtonian gravity, the axisymmetry of the
system about the black hole's velocity $\mathbf{v}$ implies that the dynamical
friction must be anti-parallel to $\mathbf{v}$. However, in general relativity
the black hole's spin $\mathbf{S}$ need not be parallel to $\mathbf{v}$,
breaking the axisymmetry of the system and generating a new component of
dynamical friction similar to the Lorentz force $\mathbf{F} = q\mathbf{v}
\times \mathbf{B}$ experienced by a particle with charge $q$ moving in a
magnetic field $\mathbf{B}$. We call this new force gravitomagnetic dynamical
friction and calculate its magnitude for a spinning black hole moving through a
field of stars with Maxwellian velocity dispersion $\sigma$, assuming that both
$v$ and $\sigma$ are much less than the speed of light $c$. We use
post-Newtonian equations of motion accurate to $\mathcal{O}(v^3/c^3)$ needed to
capture the effect of spin-orbit coupling and also include direct stellar
capture by the black hole's event horizon. Gravitomagnetic dynamical friction
will cause a black hole with uniform speed to spiral about the direction of its
spin, similar to a charged particle spiraling about a magnetic field line, and
will exert a torque on a supermassive black hole orbiting a galactic center,
causing the angular momentum of this orbit to slowly precess about the
black-hole spin. As this effect is suppressed by a factor $(\sigma/c)^2$ in
nonrelativistic systems, we expect it to be negligible in most astrophysical
contexts but provide this calculation for its theoretical interest and
potential application to relativistic systems.


title: The Impact of Particle Production on Gravitational Baryogenesis

abstract:
  Baryogenesis driven by curvature effects is investigated by taking into
account gravitationally induced particle production in the very early Universe.
In our scenario, the baryon asymmetry is generated dynamically during an
inflationary epoch powered by ultra-relativistic particles. The adiabatic
particle production rate provides both the needed negative pressure to
accelerate the radiation dominated Universe and a non-zero chemical potential
which distinguishes baryons and anti-baryons thereby producing a baryon
asymmetry in agreement with the observed value. Reciprocally, the present day
asymmetry may be used to determine the inflationary scale at early times.
Successful gravitational baryogenesis is dynamically generated for many
different choices of the relevant model parameters.


title:
Numerical study of an anisotropic Vlasov equation arising in plasma
  physics

abstract:
  Goal of this paper is to investigate several numerical schemes for the
resolution of two anisotropic Vlasov equations. These two toy-models arise from
a kinetic description of a tokamak plasma confined by strong magnetic fields.
The simplicity of our toy-models permits to better understand the features of
each scheme, in particular to investigate their asymptotic-preserving
properties, in the aim to choose then the most adequate numerical scheme for
upcoming, more realistic simulations.


title:
On Negativity and Quantum Fisher Information of an Open and Noisy System
  in the Steady State

abstract:
  In this work, we study the quantum Fisher information (QFI) per particle of
an open (particles can enter and leave the system) and dissipative (far from
thermodynamical equilibrium) steady state system of two qubits in noisy
channels. We concentrate on two noisy channels these are dephasing and
non-dephasing channels. We will show that under certain conditions QFI per
particle is slightly greater than 1 for both systems. This means that both
systems can be slightly entangled.


title: Properties of HI discs in the Auriga cosmological simulations

abstract:
  We analyse the properties of the HI gas distribution in the Auriga project, a
set of magnetohydrodynamic cosmological simulations performed with the
moving-mesh code AREPO and a physics model for galaxy formation that succeeds
in forming realistic late-type galaxies in the 30 Milky Way-sized haloes
simulated in this project. We use a simple approach to estimate the neutral
hydrogen fraction in our simulation set, which treats low-density and
star-forming gas separately, and we explore two different prescriptions to
subtract the contribution of molecular hydrogen from the total HI content. The
HI gas in the vast majority of the systems forms extended discs although more
disturbed morphologies are present. Notwithstanding the general good agreement
with observed HI properties -- such as radial profiles and the mass-diameter
relation -- the Auriga galaxies are systematically larger and more gas-rich
than typical nearby galaxies. Interestingly, the amount of HI gas outside the
disc plane correlates with the star formation rate, consistent with a picture
where most of this extra-planar HI gas originates from a fountain-like flow.
Our findings are robust with respect to the different assumptions adopted for
computing the molecular hydrogen fraction and do not vary significantly over a
wide range of numerical resolution. The HI modelling introduced in this paper
can be used in future work to build artificial interferometric HI data cubes,
allowing an even closer comparison of the gas dynamics in simulated galaxies
with observations.


title:
The globular cluster systems of 54 Coma ultra-diffuse galaxies:
  statistical constraints from HST data

abstract:
  We use data from the HST Coma Cluster Treasury program to assess the richness
of the Globular Cluster Systems (GCSs) of 54 Coma ultra-diffuse galaxies
(UDGs), 18 of which have a half-light radius exceeding 1.5 kpc. We use a
hierarchical Bayesian method tested on a large number of mock datasets to
account consistently for the high and spatially varying background counts in
Coma. These include both background galaxies and intra-cluster GCs (ICGCs),
which are disentangled from the population of member GCs in a probabilistic
fashion. We find no candidate for a GCS as rich as that of the Milky Way, our
sample has GCSs typical of dwarf galaxies. For the standard relation between
GCS richness and halo mass, 33 galaxies have a virial mass
$M_{vir}\leq10^{11}M_\odot$ at 90% probability. Only three have
$M_{vir}>10^{11}M_\odot$ with the same confidence. The mean colour and spread
in colour of the UDG GCs are indistinguishable from those of the abundant
population of ICGCs. The majority of UDGs in our sample are consistent with the
relation between stellar mass and GC richness of 'normal' dwarf galaxies. Nine
systems, however, display GCSs that are richer by a factor of 3 or more (at 90%
probability). Six of these have sizes $\lesssim1.4$ kpc. Our results imply that
the physical mechanisms responsible for the extended size of the UDGs and for
the enhanced GC richness of some cluster dwarfs are at most weakly correlated.


title: On the cut locus of free, step two Carnot groups

abstract:
  In this note, we study the cut locus of the free, step two Carnot groups
$\mathbb{G}_k$ with $k$ generators, equipped with their left-invariant
Carnot-Carath\'eodory metric. In particular, we disprove the conjectures on the
shape of the cut loci proposed in [Myasnichenko - 2002] and [Montanari,
Morbidelli - 2016], by exhibiting sets of cut points $C_k \subset \mathbb{G}_k$
which, for $k \geq 4$, are strictly larger than conjectured ones. While the
latter were, respectively, smooth semi-algebraic sets of codimension
$\Theta(k^2)$ and semi-algebraic sets of codimension $\Theta(k)$, the sets
$C_k$ are semi-algebraic and have codimension $2$, yielding the best possible
lower bound valid for all $k$ on the size of the cut locus of $\mathbb{G}_k$.
  Furthermore, we study the relation of the cut locus with the so-called
abnormal set. In the low dimensional cases, it is known that \[
\mathrm{Abn}_0(\mathbb{G}_k) = \overline{\mathrm{Cut}_0(\mathbb{G}_k)}
\setminus \mathrm{Cut}_0(\mathbb{G}_k), \qquad k=2,3. \] For each $k \geq 4$,
instead, we show that the cut locus always intersects the abnormal set, and
there are plenty of abnormal geodesics with finite cut time.
  Finally, and as a straightforward consequence of our results, we derive an
explicit lower bound for the small time heat kernel asymptotics at the points
of $C_k$.
  The question whether $C_k$ coincides with the cut locus for $k\geq 4$ remains
open.


title: The Fate of Exomoons in White Dwarf Planetary Systems

abstract:
  Roughly 1000 white dwarfs are known to be polluted with planetary material,
and the progenitors of this material are typically assumed to be asteroids. The
dynamical architectures which perturb asteroids into white dwarfs are still
unknown, but may be crucially dependent on moons liberated from parent planets
during post-main-sequence gravitational scattering. Here, we trace the fate of
these exomoons, and show that they more easily achieve deep radial incursions
towards the white dwarf than do scattered planets. Consequently, moons are
likely to play a significant role in white dwarf pollution, and in some cases
may be the progenitors of the pollution itself.


title:
Deep Chandra Observations of the Compact Starburst Galaxy Henize 2-10:
  X-rays from the Massive Black Hole

abstract:
  We present follow-up X-ray observations of the candidate massive black hole
(BH) in the nucleus of the low-mass, compact starburst galaxy Henize 2-10.
Using new high-resolution observations from the Chandra X-ray Observatory
totaling 200 ks in duration, as well as archival Chandra observations from
2001, we demonstrate the presence of a previously unidentified X-ray point
source that is spatially coincident with the known nuclear radio source in
Henize 2-10 (i.e., the massive BH). We show that the hard X-ray emission
previously identified in the 2001 observation is dominated by a source that is
distinct from the nucleus, with the properties expected for a high-mass X-ray
binary. The X-ray luminosity of the nuclear source suggests the massive BH is
radiating significantly below its Eddington limit (~10^-6 L_Edd), and the soft
spectrum resembles other weakly accreting massive BHs including Sagittarius A*.
Analysis of the X-ray light curve of the nucleus reveals the tentative
detection of a ~9-hour periodicity, although additional observations are
required to confirm this result. Our study highlights the need for sensitive
high-resolution X-ray observations to probe low-level accretion, which is the
dominant mode of BH activity throughout the Universe.


title: Line-of-sight effects in strong lensing: Putting theory into practice

abstract:
  We present a simple method to accurately infer line of sight (LOS) integrated
lensing effects for galaxy scale strong lens systems through image
reconstruction. Our approach enables us to separate weak lensing LOS effects
from the main strong lens deflector. We test our method using mock data and
show that strong lens systems can be accurate probes of cosmic shear with a
precision on the shear terms of $\pm 0.003$ (statistical error) for an HST-like
dataset. We apply our formalism to reconstruct the lens COSMOS 0038+4133 and
its LOS. In addition, we estimate the LOS properties with a halo-rendering
estimate based on the COSMOS field galaxies and a galaxy-halo connection. The
two approaches are independent and complementary in their information content.
We find that when estimating the convergence at the strong lens system,
performing a joint analysis improves the measure by a factor of two compared to
a halo model only analysis. Furthermore the constraints of the strong lens
reconstruction lead to tighter constraints on the halo masses of the LOS
galaxies. Joint constraints of multiple strong lens systems may add valuable
information to the galaxy-halo connection and may allow independent weak
lensing shear measurement calibrations.


title:
The Pairing of Accreting Massive Black Holes in Multiphase Circumnuclear
  Disks: the Interplay between Radiative Cooling, Star Formation, and Feedback
  Processes

abstract:
  We study the orbital decay of a pair of massive black holes (BHs) with masses
5 * 10^5 and 10^7 M_sun, using hydrodynamical simulations of circumnuclear
disks (CNDs) with the alternating presence of sub-grid physics such as
radiative cooling, star formation, supernova feedback, BH accretion and
feedback. In the absence of such processes, the orbit of the secondary BH
decays over timescales of ~10 Myr to the center of the CND, where the primary
BH resides. When strong dissipation operates in CNDs, fragmentation into
massive objects the size of giant molecular clouds and with densities in the
range 10^4 - 10^7 amu / cm^3 occurs, causing stochastic torques and hits that
can eject the secondary BH from the midplane. Outside the plane, the
low-density medium provides only weak drag, and the BH return is governed by
inefficient dynamical friction. In rare cases, clump-BH interactions can lead
to a faster decay. Feedback processes lead to outflows, but do not change
significantly the overall density of the CND midplane. However, with a
spherically distributed BH feedback a hot bubble is generated behind the
secondary, which almost shuts off dynamical friction, a phenomenon we dub "wake
evacuation", leading to delays in the decay of possibly ~0.3 Gyr. We discuss
the non-trivial implications on the discovery space of the eLISA telescope. Our
results suggest the largest uncertainty in predicting BH merger rates lies in
the potentially wide variety of galaxy host systems, with different degrees of
gas dissipation and heating, yielding decay timescales from ~10 to ~300 Myr.


title:
$H \rightarrow \tau^+ \tau^- \gamma$ as a Probe of the $\tau$ Magnetic
  Dipole Moment

abstract:
  Low energy observables involving the Standard Model fermions which are
chirality-violating, such as anomalous electromagnetic moments, necessarily
involve an insertion of the Higgs in order to maintain $SU(2) \times U(1)$
gauge invariance. As the result, the properties of the Higgs boson measured at
the LHC impact our understanding of the associated low-energy quantities. We
illustrate this feature with a discussion of the electromagnetic moments of the
$\tau$-lepton, as probed by the rare decay $H \rightarrow \tau^+ \tau^-
\gamma$. We assess the feasibility of measuring this decay at the LHC, and show
that the current bounds from lower energy measurements imply that $13~\rm{TeV}$
running is very likely to improve our understanding of new physics contributing
to the anomalous magnetic moment of the tau.


title:
Zooming into local active galactic nuclei: The power of combining
  SDSS-IV MaNGA with higher resolution integral field unit observations

abstract:
  Ionised gas outflows driven by active galactic nuclei (AGN) are ubiquitous in
high luminosity AGN with outflow speeds apparently correlated with the total
bolometric luminosity of the AGN. This empirical relation and theoretical work
suggest that in the range L_bol ~ 10^43-45 erg/s there must exist a threshold
luminosity above which the AGN becomes powerful enough to launch winds that
will be able to escape the galaxy potential. In this paper, we present pilot
observations of two AGN in this transitional range that were taken with the
Gemini North Multi-Object Spectrograph Integral Field Unit (IFU). Both sources
have also previously been observed within the Sloan Digital Sky Survey-IV
(SDSS) Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey.
While the MaNGA IFU maps probe the gas fields on galaxy-wide scales and show
that some regions are dominated by AGN ionization, the new Gemini IFU data zoom
into the centre with four times better spatial resolution. In the object with
the lower L_bol we find evidence of a young or stalled biconical AGN-driven
outflow where none was obvious at the MaNGA resolution. In the object with the
higher L_bol we trace the large-scale biconical outflow into the nuclear region
and connect the outflow from small to large scales. These observations suggest
that AGN luminosity and galaxy potential are crucial in shaping wind launching
and propagation in low-luminosity AGN. The transition from small and young
outflows to galaxy-wide feedback can only be understood by combining
large-scale IFU data that trace the galaxy velocity field with higher
resolution, small scale IFU maps.


title:
The weakly nonlinear magnetorotational instability in a global,
  cylindrical Taylor-Couette flow

abstract:
  We conduct a global, weakly nonlinear analysis of the magnetorotational
instability (MRI) in a Taylor-Couette flow. This is a multiscale perturbative
treatment of the nonideal, axisymmetric MRI near threshold, subject to
realistic radial boundary conditions and cylindrical geometry. We analyze both
the standard MRI, initialized by a constant vertical background magnetic field,
and the helical MRI, with an azimuthal background field component. This is the
first weakly nonlinear analysis of the MRI in a global Taylor-Couette geometry,
as well as the first weakly nonlinear analysis of the helical MRI. We find that
the evolution of the amplitude of the standard MRI is described by a real
Ginzburg-Landau equation (GLE), while the amplitude of the helical MRI takes
the form of a complex GLE. This suggests that the saturated state of the
helical MRI may itself be unstable on long spatial and temporal scales.


title: Quasiparticle approach to molecules interacting with quantum solvents

abstract:
  Understanding the behavior of molecules interacting with superfluid helium
represents a formidable challenge and, in general, requires approaches relying
on large-scale numerical simulations. Here we demonstrate that experimental
data collected over the last 20 years provide evidence that molecules immersed
in superfluid helium form recently-predicted angulon quasiparticles [Phys. Rev.
Lett. 114, 203001 (2015)]. Most importantly, casting the many-body problem in
terms of angulons amounts to a drastic simplification and yields effective
molecular moments of inertia as straightforward analytic solutions of a simple
microscopic Hamiltonian. The outcome of the angulon theory is in good agreement
with experiment for a broad range of molecular impurities, from heavy to
medium-mass to light species. These results pave the way to understanding
molecular rotation in liquid and crystalline phases in terms of the angulon
quasiparticle.

categories: physics.chem-ph cond-mat.mes-hall cond-mat.quant-gas physics.atm-clus physics.atom-ph


title:
Measurement of the X-ray proper motion in the south-east rim of RX
  J1713.7-3946

abstract:
  We report on the first proper motion measurement in the supernova remnant RX
J1713.7-3946 using the XMM-Newton X-ray telescope on a 13 year time interval.
This expansion measurement is carried out in the south-east region of the
remnant where two sharp filament structures are observed. For the outermost
filament, the proper motion is $0.73\pm0.047_{\rm stat} \pm 0.069_{\rm syst}$
arcsec yr$^{-1}$ which is equivalent to a shock speed of 3500 km s$^{-1}$ at a
distance of 1 kpc. In contrast with the bright north-west region where the
shock is interacting with the border of the cavity, the shock in the south-east
region is probably expanding in the original ambient medium carved by the
progenitor and can be used to derive the current density at the shock and the
age of the remnant. In the case where the shock is evolving in a wind profile
($\rho \propto r^{-s}$, s=2) or in a uniform medium (s=0), we estimate an age
of 2300 yrs and 1800 yrs respectively for an ejecta power-law index n=9. The
specific case of n=7 and s=0, yields an age of 1550 yrs which would reconcile
RX J1713.7-3946 with the historical records of SN 393. In all scenarios, we
derive similar upstream densities of the order of 0.01 cm$^{-3}$, compatible
with the lack of thermal X-rays from the shocked ambient medium.


title: Slowly-growing gap-opening planets trigger weaker vortices

abstract:
  The presence of a giant planet in a low-viscosity disc can create a gap edge
in the disc's radial density profile sharp enough to excite the Rossby Wave
Instability. This instability may evolve into dust-trapping vortices that might
explain the "banana-shaped" features in recently observed asymmetric transition
discs with inner cavities. Previous hydrodynamical simulations of
planet-induced vortices have neglected the timescale of hundreds to thousands
of orbits to grow a massive planet to Jupiter-size. In this work, we study the
effect of a giant planet's runaway growth timescale on the lifetime and
characteristics of the resulting vortex. For two different planet masses (1 and
5 Jupiter masses) and two different disc viscosities ($\alpha$=3$\times
10^{-4}$ and 3$\times10^{-5}$), we compare the vortices induced by planets with
several different growth timescales between 10 and 4000 planet orbits. In
general, we find that slowly-growing planets create significantly weaker
vortices with lifetimes and surface densities reduced by more than $50\%$. For
the higher disc viscosity, the longest growth timescales in our study inhibit
vortex formation altogether. Additionally, slowly-growing planets produce
vortices that are up to twice as elongated, with azimuthal extents well above
$180^{\circ}$ in some cases. These unique, elongated vortices likely create a
distinct signature in the dust observations that differentiates them from the
more concentrated vortices that correspond to planets with faster growth
timescales. Lastly, we find that the low viscosities necessary for vortex
formation likely prevent planets from growing quickly enough to trigger the
instability in self-consistent models.


title: One-point fluctuation analysis of the high-energy neutrino sky

abstract:
  We perform the first one-point fluctuation analysis of the high-energy
neutrino sky. This method reveals itself to be especially suited to
contemporary neutrino data, as it allows to study the properties of the
astrophysical components of the high-energy flux detected by the IceCube
telescope, even with low statistics and in the absence of point source
detection. Besides the veto-passing atmospheric foregrounds, we adopt a simple
model of the high-energy neutrino background by assuming two main
extra-galactic components: star-forming galaxies and blazars. By leveraging
multi-wavelength data from Herschel and Fermi, we predict the spectral and
anisotropic probability distributions for their expected neutrino counts in
IceCube. We find that star-forming galaxies are likely to remain a diffuse
background due to the poor angular resolution of IceCube, and we determine an
upper limit on the number of shower events that can reasonably be associated to
blazars. We also find that upper limits on the contribution of blazars to the
measured flux are unfavourably affected by the skewness of the blazar flux
distribution. One-point event clustering and likelihood analyses of the IceCube
HESE data suggest that this method has the potential to dramatically improve
over more conventional model-based analyses, especially for the next generation
of neutrino telescopes.


title: Factorization for the light-jet mass and hemisphere soft function

abstract:
  Many collider observables suffer from non-global logarithms not captured by
standard resummation techniques. Classic examples are the light-jet mass event
shape in the limit of small mass and the related hemisphere soft function. We
derive factorization formulas for both of these and explicitly demonstrate that
they capture all logarithms present at NNLO. These formulas achieve full scale
separation and provide the basis for all-order resummations. A characteristic
feature of non-global observables is that the soft radiation is driven by
multi-Wilson-line operators, and the ones arising here map onto those relevant
for the case of narrow-cone jet cross sections. Numerically, the contributions
of non-global logarithms to resummed hemisphere-mass event shapes are sizeable.


title:
The Dragonfly Nearby Galaxies Survey. II. Ultra diffuse galaxies near
  the elliptical galaxy NGC 5485

abstract:
  We present the unexpected discovery of four ultra diffuse galaxies (UDGs) in
a group environment. We recently identified seven extremely low surface
brightness galaxies in the vicinity of the spiral galaxy M101, using data from
the Dragonfly Telephoto Array. The galaxies have effective radii of $10"-38"$
and central surface brightnesses of $25.6-27.7$ mag arcsec$^{-2}$ in g-band. We
subsequently obtained follow-up observations with $HST$ to constrain the
distances to these galaxies. Four remain persistently unresolved even with the
spatial resolution of $HST$/ACS, which implies distances of $D > 17.5$ Mpc. We
show that the galaxies are most likely associated with a background group at
$\sim 27$ Mpc containing the massive ellipticals NGC 5485 and NGC 5473. At this
distance, the galaxies have sizes of $2.6-4.9$ kpc, and are classified as UDGs,
similar to the populations that have been revealed in clusters such as Coma,
Virgo and Fornax, yet even more diffuse. The discovery of four UDGs in a galaxy
group demonstrates that the UDG phenomenon is not exclusive to cluster
environments. Furthermore, their morphologies seem less regular than those of
the cluster populations, which may suggest a different formation mechanism or
be indicative of a threshold in surface density below which UDGs are unable to
maintain stability.


title:
Exoplanetary atmospheric sodium revealed by the orbital motion.
  Narrow-band transmission spectroscopy of HD 189733b with UVES

abstract:
  During primary transits, the spectral signatures of an exoplanet atmosphere
can be measured using transmission spectroscopy. The goal of this work is to
accurately measure the atomspheric sodium absorption light curve in HD189733b,
correcting for the effects of stellar differential limb-darkening, stellar
activity and a "bump" caused by the changing radial velocity of the exoplanet.
In fact, due to the high cadence and quality of our data, it is the first time
that the last feature can be detected even by visual inspection. We use 244
high-resolution optical spectra taken by the UVES instrument mounted at the
VLT. Our observations cover a full transit of HD 189733b, with a cadence of 45
seconds. To probe the transmission spectrum of sodium we produce excess light-
curves integrating the stellar flux in passbands of 1 \AA, 1.5 \AA, and 3 \AA
inside the core of each sodium D-line. We model the effects of external sources
on the excess light-curves, which correspond to an observed stellar flare
beginning close to mid-transit time and the wavelength dependent limb-darkening
effects. In addition, by characterizing the effect of the changing radial
velocity and Doppler shifts of the planetary sodium lines inside the stellar
sodium lines, we estimate the depth and width of the exoplanetary sodium
feature. We estimate the shape of the planetary sodium line by a Gaussian
profile, with an equivalent width of 0.0023 \pm 0.0010 \AA, thereby confirming
the presence of sodium in the atmosphere of HD189733b with excess absorption
levels of 0.72 \pm 0.25%, 0.34 \pm 0.11%, and 0.20 \pm 0.06% for the
integration bands of 1 \AA, 1.5 \AA, and 3 \AA, respectively. From these, we
produce a first order estimate of the number density of sodium in the exoplanet
atmosphere.


title:
Higher-Harmonic Collective Modes in a Trapped Gas from Second-Order
  Hydrodynamics

abstract:
  Utilizing a second-order hydrodynamics formalism, the dispersion relations
for the frequencies and damping rates of collective oscillations as well as
spatial structure of these modes up to the decapole oscillation in both two-
and three- dimensional gas geometries are calculated. In addition to
higher-order modes, the formalism also gives rise to purely damped
"non-hydrodynamic" modes. We calculate the amplitude of the various modes for
both symmetric and asymmetric trap quenches, finding excellent agreement with
an exact quantum mechanical calculation. We find that higher-order hydrodynamic
modes are more sensitive to the value of shear viscosity, which may be of
interest for the precision extraction of transport coefficients in Fermi gas
systems.


title:
Fast Pairwise Conversion of Supernova Neutrinos: A Dispersion-Relation
  Approach

abstract:
  Collective pair conversion $\nu_e\bar\nu_e\leftrightarrow \nu_{x}\bar\nu_{x}$
by forward scattering, where $x=\mu$ or $\tau$, may be generic for supernova
neutrino transport. Depending on the local angular intensity of the electron
lepton number carried by neutrinos, the conversion rate is "fast," i.e., of the
order of $\sqrt{2}G_{\rm{F}}(n_{\nu_e}{-}\,n_{\bar\nu_e})\gg\Delta m^2_{\rm
atm}/2E$. We present a novel approach to understand these phenomena: A
dispersion relation for the frequency and wave number $(\Omega,\bf{K})$ of
disturbances in the mean field of $\nu_e\nu_x$ flavor coherence. Run-away
solutions occur in "dispersion gaps," i.e., in "forbidden" intervals of
$\Omega$ and/or $\bf{K}$ where propagating plane waves do not exist. We stress
that the actual solutions also depend on the initial and/or boundary conditions
which need to be further investigated.


title: Signatures of Many-Body Localization in a Controlled Open Quantum System

abstract:
  In the presence of disorder, an interacting closed quantum system can undergo
many-body localization (MBL) and fail to thermalize. However, over long times
even weak couplings to any thermal environment will necessarily thermalize the
system and erase all signatures of MBL. This presents a challenge for
experimental investigations of MBL, since no realistic system can ever be fully
closed. In this work, we experimentally explore the thermalization dynamics of
a localized system in the presence of controlled dissipation. Specifically, we
find that photon scattering results in a stretched exponential decay of an
initial density pattern with a rate that depends linearly on the scattering
rate. We find that the resulting susceptibility increases significantly close
to the phase transition point. In this regime, which is inaccessible to current
numerical studies, we also find a strong dependence on interactions. Our work
provides a basis for systematic studies of MBL in open systems and opens a
route towards extrapolation of closed system properties from experiments.

categories: cond-mat.quant-gas cond-mat.dis-nn cond-mat.stat-mech cond-mat.str-el quant-ph


title:
Anatomy of the internal bow shocks in the IRAS 04166+2706 protostellar
  jet

abstract:
  $Aims.$ We study the relation between the jet and the outflow in the IRAS
04166+2706 protostar. This Taurus protostar drives a molecular jet that
contains multiple emission peaks symmetrically located from the central source.
The protostar also drives a wide-angle outflow consisting of two conical
shells.
  $Methods.$ We have used the Atacama Large Millimeter/submillimeter Array
(ALMA) interferometer to observe two fields along the IRAS 04166+2706 jet. The
fields were centered on a pair of emission peaks that correspond to the same
ejection event, and were observed in CO(2-1), SiO(5-4), and SO(65-54).
  $ Results.$ Both ALMA fields present spatial distributions that are
approximately elliptical and have their minor axes aligned with the jet
direction. As the velocity increases, the emission in each field moves
gradually across the elliptical region. This systematic pattern indicates that
the emitting gas in each field lies in a disk-like structure that is
perpendicular to the jet axis and is expanding away from the jet. A small
degree of curvature in the first-moment maps indicates that the disks are
slightly curved in the manner expected for bow shocks moving away from the IRAS
source. A simple geometrical model confirms that this scenario fits the main
emission features.
  $Conclusions.$ The emission peaks in the IRAS 04166+2706 jet likely represent
internal bow shocks where material is being ejected laterally away from the jet
axis. While the linear momentum of the ejected gas is dominated by the
component in the jet direction, the sideways component is not negligible, and
can potentially affect the distribution of gas in the surrounding outflow and
core.


title: Temperature Evolution of Molecular Clouds in the Central Molecular Zone

abstract:
  We infer the absolute time dependence of kinematic gas temperature along a
proposed orbit of molecular clouds in the Central Molecular Zone (CMZ) of the
Galactic Center (GC). Ammonia gas temperature maps are one of the results of
the "Survey of Water and Ammonia in the Galactic Center" (SWAG, PI: J. Ott);
the dynamical model of molecular clouds in the CMZ was taken from Kruijssen et
al. (2015). We find that gas temperatures increase as a function of time in
both regimes before and after the cloud passes pericenter on its orbit in the
GC potential. This is consistent with the recent proposal that pericenter
passage triggers gravitational collapse. Other investigated quantities (line
width, column density, opacity) show no strong sign of time dependence but are
likely dominated by cloud-to-cloud variations.


title: The weakly nonlinear magnetorotational instability in a local geometry

abstract:
  The magnetorotational instability (MRI) is a fundamental process of accretion
disk physics, but its saturation mechanism remains poorly understood despite
considerable theoretical and computational effort. We present a multiple scales
analysis of the non-ideal MRI in the weakly nonlinear regime -- that is, when
the most unstable MRI mode has a growth rate asymptotically approaching zero
from above. Here, we develop our theory in a local, Cartesian channel. Our
results confirm the finding by Umurhan et al. (2007) that the perturbation
amplitude follows a Ginzburg-Landau equation. We further find that the
Ginzburg-Landau equation will arise for the local MRI system with
shear-periodic boundary conditions when the effects of ambipolar diffusion are
considered. A detailed force balance for the saturated azimuthal velocity and
vertical magnetic field demonstrates that even when diffusive effects are
important, the bulk flow saturates via the combined processes of reducing the
background shear and rearranging and strengthening the background vertical
magnetic field. We directly simulate the Ginzburg-Landau amplitude evolution
for our system and demonstrate the pattern formation our model predicts on long
length and time scales. We compare the weakly nonlinear theory results to a
direct numerical simulation of the MRI in a thin-gap Taylor Couette flow.


title:
3C 279 in Outburst in June 2015: A Broadband-SED Study Based on the
  INTEGRAL Detection

abstract:
  Blazars radiate from radio through gamma-ray frequencies thereby being ideal
targets for multifrequency studies. Such studies allow constraining the
properties of the emitting jet. 3C 279 is among the most notable blazars and
therefore subject to extensive multifrequency campaigns. We report the results
of a campaign ranging from near-IR to gamma-ray energies of an outburst of 3C
279 in June 2015. The overall spectral energy distribution from near-IR to
gamma rays can be well represented by either a leptonic or a lepto-hadronic
radiation transfer model. Even though the data are equally well represented by
the two models, their inferred parameters challenge the physical conditions in
the jet. In fact, the leptonic model requires parameters with a magnetic field
far below equipartition with the relativistic particle energy density. On the
contrary, equipartition may be achieved with the lepto-hadronic model, which
however implies an extreme total jet power close to Eddington luminosity.


title:
Time to Go Beyond Triple-Gauge-Boson-Coupling Interpretation of $W$ Pair
  Production

abstract:
  $W$ boson pair production processes at $e^+e^-$ and $pp$ colliders have been
conventionally interpreted as measurements of $WWZ$ and $WW\gamma$ triple gauge
couplings (TGCs). Such interpretation is based on the assumption that new
physics effects other than anomalous TGCs are negligible. While this "TGC
dominance assumption" was well-motivated and useful at LEP2 thanks to precision
electroweak constraints, it is already challenged by recent LHC data. In fact,
contributions from anomalous $Z$ boson couplings that are allowed by
electroweak precision data but neglected in LHC analyses, being enhanced at
high energy, can even dominate over those from the anomalous TGCs considered.
This limits the generality of the anomalous TGC constraints derived in current
analyses, and necessitates extension of the analysis framework and change of
physics interpretation. The issue will persist as we continue to explore the
high energy frontier. We clarify and analyze the situation in the effective
field theory framework, which provides a useful organizing principle for
understanding Standard Model deviations in the high energy regime.


title:
Revisiting the Completeness and the Luminosity Function in High-Redshift
  Low-Luminosity Quasar Surveys

abstract:
  Recent studies have derived quasar luminosity functions (QLFs) at various
redshifts. However, the faint side of the QLF at high redshifts is still too
uncertain. An accurate estimate of the survey completeness is essential to
derive an accurate QLF for use in studying the luminosity-dependent density
evolution of the quasar population. Here we investigate how the luminosity
dependence of quasar spectra (the Baldwin effect) and the attenuation model for
the inter-galactic medium (IGM) affect the completeness estimates. For this
purpose, we revisit the completeness of quasar surveys specifically at
$z\sim4-5$, using the COSMOS images observed with Subaru/Suprime-Cam. As the
result, we find that the completeness estimates are sensitive to the luminosity
dependence of the quasar spectrum and difference in the IGM attenuation models.
At $z\sim4$, the number density of quasars when we adopt the latest IGM model
and take the luminosity dependence of spectra into account are
$(3.49\pm1.62)\times10^{-7}$ Mpc$^{-3}$ mag$^{-1}$ for $-24.09<M_{1450}<-23.09$
and $(5.24\pm2.13)\times10^{-7}$ Mpc$^{-3}$ mag$^{-1}$ for
$-23.09<M_{1450}<-22.09$, respectively, which are $\sim$$24$$\%$ lower than
that estimated by the conventional method. On the other hand, at $z\sim5$, a
$1\sigma$ confidence upper limit of the number density at
$-24.5<M_{1450}<-22.5$ in our new estimates is $\sim$$43$$\%$ higher than that
estimated previously. The results suggest that the luminosity dependence of the
quasar spectrum and the IGM model are important for deriving accurate number
density of high-$z$ quasars. Even taking these effects into account, the
inferred luminosity-dependent density evolution of quasars is consistent with
the AGN down-sizing evolutionary picture.


title: F-brane Dynamics

abstract:
  We generalize the current algebra of constraints of U-duality-covariant
critical superstrings to include the generator responsible for the dynamics of
the fundamental brane. This allows us to define $\kappa$ symmetry and to write
a worldvolume action in Hamiltonian form that is manifestly supersymmetric in
the target space. The Lagrangian form of this action is generally covariant,
but the worldvolume metric has fewer components than expected.


title: Ideas about the Jacobian Conjecture

abstract:
  Let $F:\mathbb{C}[x_1,\ldots,x_n] \to \mathbb{C}[x_1,\ldots,x_n]$ be a
$\mathbb{C}$-algebra endomorphism that has an invertible Jacobian. We bring two
ideas concerning the Jacobian Conjecture: First, we conjecture that for all
$n$, the degree of the field extension $\mathbb{C}(F(x_1),\ldots,F(x_n))
\subseteq \mathbb{C}(x_1,\ldots,x_n)$ is less than or equal to $d^{n-1}$, where
$d$ is the minimum of the degrees of the $F(x_i)$'s. If this conjecture is
true, then the generalized Jacobian Conjecture is true. Second, we suggest to
replace in some known theorems the assumption on the degrees of the $F(x_i)$'s
by a similar assumption on the degrees of the minimal polynomials of the
$x_i$'s over $\mathbb{C}(F(x_1)\ldots,f(x_n))$; this way we obtain some
analogous results to the known ones.


title:
Finite-dimensional colored fluctuation-dissipation theorem for spin
  systems

abstract:
  When nano-magnets are coupled to random external sources, their magnetization
becomes a random variable, whose properties are defined by an induced
probability density, that can be reconstructed from its moments, using the
Langevin equation, for mapping the noise to the dynamical degrees of freedom.
When the spin dynamics is discretized in time, a general
fluctuation-dissipation theorem, valid for non-Markovian noise, can be
established, even when zero modes are present. We discuss the subtleties that
arise, when Gilbert damping is present and the mapping between noise and spin
degrees of freedom is non--linear.

categories: cond-mat.stat-mech hep-lat math-ph math.MP quant-ph


title:
KMOS view of the Galactic Centre - II. Metallicity distribution of
  late-type stars

abstract:
  Knowing the metallicity distribution of stars in the Galactic Centre has
important implications for the formation history of the Milky Way nuclear star
cluster. However, this distribution is not well known, and is currently based
on a small sample of fewer than 100 stars. We obtained near-infrared K-band
spectra of more than 700 late-type stars in the central 4 pc^2 of the Milky Way
nuclear star cluster with the integral-field spectrograph KMOS (VLT). We
analyse the medium-resolution spectra using a full-spectral fitting method
employing the G\"ottingen Spectral library of synthetic PHOENIX spectra. The
derived stellar metallicities range from metal-rich [M/H]>+0.3 dex to
metal-poor [M/H]<-1.0 dex, with a fraction of 5.2(^{+6.0}+{-3.1}) per cent
metal-poor ([M/H]<-0.5 dex) stars. The metal-poor stars are distributed over
the entire observed field. The origin of metal-poor stars remains unclear. They
could originate from infalling globular clusters. For the metal-rich stellar
population ([M/H]>0 dex) a globular cluster origin can be ruled out. As there
is only a very low fraction of metal-poor stars in the central 4 pc^2 of the
Galactic Centre, we believe that our data can discard a scenario in which the
Milky Way nuclear star cluster is purely formed from infalling globular
clusters.


title:
Testing the Large-Scale Environments of Cool-core and Noncool-core
  Clusters with Clustering Bias

abstract:
  There are well-observed differences between cool-core (CC) and non-cool-core
(NCC) clusters, but the origin of this distinction is still largely unknown.
Competing theories can be divided into internal (inside-out), in which internal
physical processes transform or maintain the NCC phase, and external
(outside-in), in which the cluster type is determined by its initial
conditions, which in turn lead to different formation histories (i.e., assembly
bias). We propose a new method that uses the relative assembly bias of CC to
NCC clusters, as determined via the two-point cluster-galaxy cross-correlation
function (CCF), to test whether formation history plays a role in determining
their nature. We apply our method to 48 ACCEPT clusters, which have well
resolved central entropies, and cross-correlate with the SDSS-III/BOSS LOWZ
galaxy catalog. We find that the relative bias of NCC over CC clusters is $b =
1.42 \pm 0.35$ ($1.6\sigma$ different from unity). Our measurement is limited
by the small number of clusters with core entropy information within the BOSS
footprint, 14 CC and 34 NCC. Future compilations of X-ray cluster samples,
combined with deep all-sky redshift surveys, will be able to better constrain
the relative assembly bias of CC and NCC clusters and determine the origin of
the bimodality.


title:
Timing Observations of PSR J1023+0038 During a Low-Mass X-ray Binary
  State

abstract:
  Transitional millisecond pulsars (tMSPs) switch, on roughly multi-year
timescales, between rotation-powered radio millisecond pulsar (RMSP) and
accretion-powered low-mass X-ray binary (LMXB) states. The tMSPs have raised
several questions related to the nature of accretion flow in their LMXB state
and the mechanism that causes the state switch. The discovery of coherent X-ray
pulsations from PSR J1023+0038 (while in the LMXB state) provides us with the
first opportunity to perform timing observations and to compare the neutron
star's spin variation during this state to the measured spin-down in the RMSP
state. Whereas the X-ray pulsations in the LMXB state likely indicate that some
material is accreting onto the neutron star's magnetic polar caps, radio
continuum observations indicate the presence of an outflow. The fraction of the
inflowing material being ejected is not clear, but it may be much larger than
that reaching the neutron star's surface. Timing observations can measure the
total torque on the neutron star. We have phase-connected nine XMM-Newton
observations of PSR J1023+0038 over the last 2.5 years of the LMXB state to
establish a precise measurement of spin evolution. We find that the average
spin-down rate as an LMXB is 26.8+/-0.4% faster than the rate (-2.39x10^-15 Hz
s-1) determined during the RMSP state. This shows that negative angular
momentum contributions (dipolar magnetic braking and outflow) exceed positive
ones (accreted material), and suggests that the pulsar wind continues to
operate at a largely unmodified level. We discuss implications of this tight
observational constraint in the context of possible accretion models.


title:
MUFASA: Galaxy star formation, gas, and metal properties across cosmic
  time

abstract:
  We examine galaxy star formation rates (SFRs), metallicities, and gas
contents predicted by the MUFASA cosmological hydrodynamic simulations, which
employ meshless hydrodynamics and novel feedback prescriptions that yield a
good match to observed galaxy stellar mass assembly. We combine 50, 25, and
12.5 Mpc/h boxes with a quarter billion particles each to show that MUFASA
broadly reproduces a wide range of relevant observations, including SFR and
specific SFR functions, the mass-metallicity relation, HI and H2 fractions, HI
(21 cm) and CO luminosity functions, and cosmic gas density evolution. There
are mild but significant discrepancies, such as too many high-SFR galaxies,
overly metal-rich and HI-poor galaxies at M*>10^{10} Mo, and sSFRs that are too
low at z~1-2. The HI mass function increases by x2 out to z~1 then steepens to
higher redshifts, while the CO luminosity function computed using the Narayanan
et al. conversion factor shows a rapid increase of CO-bright galaxies out to
z~2 in accord with data. Omega_HI and Omega_H2 both scale roughly as (1+z)^0.7
out to z~3, comparable to the rise in HI and H2 fractions. MUFASA galaxies with
high SFR at a given M* have lower metallicities and higher HI and H2 fractions,
following observed trends; we make quantitative predictions for how
fluctuations in the baryon cycle drive correlated scatter around galaxy scaling
relations. Most of these trends are well converged with numerical resolution.
These successes highlight MUFASA as a viable platform to study many facets of
cosmological galaxy evolution.


title:
Gas kinematics in powerful radio galaxies at z~2: Energy supply from
  star formation, AGN, and radio jet

abstract:
  We compare the kinetic energy and momentum injection rates from intense star
formation, bolometric AGN radiation, and radio jets with the kinetic energy and
momentum observed in the warm ionized gas in 24 powerful radio galaxies at z~2.
These galaxies are amongst our best candidates for being massive galaxies near
the end of their active formation period, when intense star formation, quasar
activity, and powerful radio jets all co-exist. All galaxies have VLT/SINFONI
imaging spectroscopy of the rest-frame optical line emission, showing
emission-line regions with large velocity offsets (up to 1500 km/s) and line
widths (typically 800-1000 km/s) consistent with very turbulent, often
outflowing gas. As part of the HeRGE sample, they also have FIR estimates of
the star formation and quasar activity obtained with Herschel/PACS and SPIRE,
which enables us to measure the relative energy and momentum release from each
of the three main sources of feedback in massive, star-forming AGN host
galaxies during their most rapid formation phase. We find that star formation
falls short by factors 10-1000 of providing the energy and momentum necessary
to power the observed gas kinematics. The obscured quasars in the nuclei of
these galaxies provide enough energy and momentum in about half of the sample,
however, only if these are transfered to the gas relatively efficiently. We
compare with theoretical and observational constraints on the efficiency of the
energy and momentum transfer from jet and AGN radiation, which advocates that
the radio jet is the main driver of the gas kinematics.


title: Once more on parastatistics

abstract:
  Equivalence between algebraic structures generated by parastatisticstriple
relations of Green (1953) and Greenberg -- Messiah (1965), and certain
orthosymplectic $\mathbb{Z}_2\times \mathbb{Z}_2$-graded Lie superalgebras is
found explicitly. Moreover, it is shown that such superalgebras give more
complex para-Fermi and para-Bose systems then ones of Green -- Greenberg --
Messiah.


title:
Power countings versus physical scalings in disordered elastic systems -
  Case study of the one-dimensional interface

abstract:
  We study the scaling properties of a one-dimensional interface at
equilibrium, at finite temperature and in a disordered environment with a
finite disorder correlation length. We focus our approach on the scalings of
its geometrical fluctuations as a function of its length. At large
lengthscales, the roughness of the interface, defined as the variance of its
endpoint fluctuations, follows a power-law behaviour whose exponent
characterises its superdiffusive behaviour. In 1+1 dimensions, the roughness
exponent is known to be the characteristic 2/3 exponent of the
Kardar-Parisi-Zhang (KPZ) universality class. An important feature of the model
description is that its Flory exponent, obtained by a power counting argument
on its Hamiltonian, is equal to 3/5 and thus does not yield the correct KPZ
roughness exponent. In this work, we review the available power-counting
options, and relate the physical validity of the exponent values that they
predict, to the existence (or not) of well-defined optimal trajectories in a
large-size or low-temperature asymptotics. We identify the crucial role of the
'cut-off' lengths of the problem (the disorder correlation length and the
system size), which one has to carefully follow throughout the scaling
analysis. To complement the latter, we device a novel Gaussian Variational
Method (GVM) scheme to compute the roughness, taking into account the effect of
a large but finite interface length. Interestingly, such a procedure yields the
correct KPZ roughness exponent, instead of the Flory exponent usually obtained
through the GVM approach for an infinite interface. We explain the physical
origin of this improvement of the GVM procedure and discuss possible extensions
of this work to other disordered systems.


title: Counting Geodesic Paths in 1D VANETs

abstract:
  In the IEEE 802.11p standard addressing vehicular communications, Basic
Safety Messages (BSMs) can be bundled together and relayed as to increase the
effective communication range of transmitting vehicles. This process forms a
vehicular ad hoc network (VANET) for the dissemination of safety information.
The number of "shortest multihop paths" (or geodesics) connecting two network
nodes is an important statistic which can be used to enhance throughput,
validate threat events, protect against collusion attacks, infer location
information, and also limit redundant broadcasts thus reducing interference. To
this end, we analytically calculate for the first time the mean and variance of
the number of geodesics in 1D VANETs.


title: Simple High-Bandwidth Sideband Locking with Heterodyne Readout

abstract:
  We present a robust sideband laser locking technique that is ideally suited
for applications requiring low probe power and heterodyne readout. By feeding
back to a high-bandwidth voltage controlled oscillator, we lock a first-order
phase-modulation sideband to a table-top high-finesse Fabry-Perot cavity,
achieving a feedback bandwidth of 3.5 MHz with a single integrator, limited
fundamentally by the signal delay. The directly measured transfer function of
the closed feedback loop agrees with a model assuming ideal system components,
and from this we suggest a modified design that should realistically achieve a
bandwidth exceeding 6 MHz with a near-causally limited feedback gain of
$4\times 10^7$ at 1 kHz. The off-resonance optical carrier is used for
alignment-free heterodyne readout, alleviating the need for a second laser or
additional optical modulators.


title: X-rays from the location of the Bactrian Transient ASASSN-15lh

abstract:
  We present the detection of persistent soft X-ray radiation with L_x ~
10^41-10^42 erg/s at the location of the extremely luminous, double-humped
transient ASASSN-15lh as revealed by Chandra and Swift. We interpret this
finding in the context of observations from our multiwavelength campaign, which
revealed the presence of weak narrow nebular emission features from the
host-galaxy nucleus and clear differences with respect to superluminous
supernova optical spectra. Significant UV flux variability on short time-scales
detected at the time of the re-brightening disfavors the shock interaction
scenario as the source of energy powering the long-lived UV emission, while
deep radio limits exclude the presence of relativistic jets propagating into a
low-density environment. We propose a model where the extreme luminosity and
double-peaked temporal structure of ASASSN-15lh is powered by a central source
of ionizing radiation that produces a sudden change of the ejecta opacity at
later times. As a result, UV radiation can more easily escape, producing the
second bump in the light-curve. We discuss different interpretations for the
intrinsic nature of the ionizing source. We conclude that, IF the X-ray source
is physically associated with the optical-UV transient, ASASSN-15lh most likely
represents the tidal disruption of a main-sequence star by the most massive
spinning black hole detected to date. In this case, ASASSN-15lh and similar
events discovered in the future would constitute the most direct probes of very
massive, dormant, spinning, supermassive black holes in galaxies. Future
monitoring of the X-rays may allow us to distinguish between the supernova and
TDE hypothesis.


title:
Binary classification of multi-channel EEG records based on the
  $\epsilon$-complexity of continuous vector functions

abstract:
  A methodology for binary classification of EEG records which correspond to
different mental states is proposed. This model-free methodology is based on
our theory of the $\epsilon$-complexity of continuous functions which is
extended here (see Appendix) to the case of vector functions. This extension
permits us to handle multichannel EEG recordings. The essence of the
methodology is to use the $\epsilon$-complexity coefficients as features to
classify (using well known classifiers) different types of vector functions
representing EEG-records corresponding to different types of mental states. We
apply our methodology to the problem of classification of multichannel
EEG-records related to a group of healthy adolescents and a group of
adolescents with schizophrenia. We found that our methodology permits accurate
classification of the data in the four-dimensional feather space of the
$\epsilon$-complexity coefficients.


title:
Observation of the Wigner-Huntington Transition to Solid Metallic
  Hydrogen

abstract:
  We have studied solid hydrogen under pressure at low temperatures. With
increasing pressure we observe changes in the sample, going from transparent,
to black, to a reflective metal, the latter studied at a pressure of 495 GPa.
We have measured the reflectance as a function of wavelength in the visible
spectrum finding values as high as 0.90 from the metallic hydrogen. We have fit
the reflectance using a Drude free electron model to determine the plasma
frequency of 30.1 eV at T= 5.5 K, with a corresponding electron carrier density
of 6.7x1023 particles/cm3, consistent with theoretical estimates. The
properties are those of a metal. Solid metallic hydrogen has been produced in
the laboratory.


abstract:
  We define Laguerre and Jacobi analogues of the Warren process. That is, we
construct local dynamics on a triangular array of particles so that the
projections to each level recover the Laguerre and Jacobi eigenvalue processes
of K\"onig-O'Connell and Doumerc and the fixed time distributions recover the
joint distribution of eigenvalues in multilevel Laguerre and Jacobi random
matrix ensembles. Our techniques extend and generalize the framework of
intertwining diffusions developed by Pal-Shkolnikov. One consequence is the
construction of particle systems with local interactions whose fixed time
distribution recovers the hard edge of random matrix theory. An appendix by
Andrey Sarantsev establishes strong existence and uniqueness for solutions to
SDER's satisfied by these processes.


title:
An inversion method based on random sampling for real-time MEG
  neuroimaging

abstract:
  The MagnetoEncephaloGraphy (MEG) has gained great interest in
neurorehabilitation training due to its high temporal resolution. The challenge
is to localize the active regions of the brain in a fast and accurate way. In
this paper we use an inversion method based on random spatial sampling to solve
the real-time MEG inverse problem. Several numerical tests on synthetic but
realistic data show that the method takes just a few hundredths of a second on
a laptop to produce an accurate map of the electric activity inside the brain.
Moreover, it requires very little memory storage. For this reasons the random
sampling method is particularly attractive in real-time MEG applications.


title: Universality of the Stochastic Bessel Operator

abstract:
  We establish universality at the hard edge for general beta ensembles
provided that the background potential V is a polynomial such that x -> V(x^2)
is uniformly convex and beta is larger than or equal to one. The method rests
on the corresponding tridiagonal matrix models, showing that their appropriate
continuum scaling limit is given by the Stochastic Bessel Operator. As
conjectured by Edelman-Sutton and rigorously established by Ramirez-Rider, the
latter characterizes the hard edge in the case of linear potential and all beta
(the classical "beta-Laguerre" ensembles)


title:
Constraining the UV emissivity of AGN throughout cosmic time via X-ray
  surveys

abstract:
  The cosmological process of hydrogen (HI) reionization in the intergalactic
medium is thought to be driven by UV photons emitted by star-forming galaxies
and ionizing active galactic nuclei (AGN). The contribution of QSOs to HI
reionization at $z>4$ has been traditionally believed to be quite modest.
However, this view has been recently challenged by new estimates of a higher
faint-end UV luminosity function (LF). To set firmer constraints on the
emissivity of AGN at $z<6$, we here make use of complete X-ray selected samples
including deep Chandra and new COSMOS data, capable to efficiently measure the
1 ryd comoving AGN emissivity up to $z\sim5-6$ and down to five magnitudes
fainter than probed by current optical surveys, without any luminosity
extrapolation. We find good agreement between the logN$\rm{_H}\lesssim21-22$
cm$^{-2}$ X-ray LF and the optically-selected QSO LF at all redshifts for
$M_{1450}\leq -23$. The full range of the logN$\rm{_H}\lesssim21-22$ cm$^{-2}$
LF ($M_{1450} \leq -17$) was then used to quantify the contribution of AGN to
the photon budget critical value needed to keep the Universe ionized. We find
that the contribution of ionizing AGN at $z = 6$ is as small as 1\% - 7\%, and
very unlikely to be greater than 30\%, thus excluding an AGN-dominated
reionization scenario.


title:
Standard Model-Axion-Seesaw-Higgs Portal Inflation. Five problems of
  particle physics and cosmology solved in one stroke

abstract:
  We present a minimal extension of the Standard Model (SM) providing a
consistent picture of particle physics from the electroweak scale to the Planck
scale and of cosmology from inflation until today. Three right-handed neutrinos
$N_i$, a new color triplet $Q$ and a complex SM-singlet scalar $\sigma$, whose
vacuum expectation value $v_\sigma \sim 10^{11}$ GeV breaks lepton number and a
Peccei-Quinn symmetry simultaneously, are added to the SM. At low energies, the
model reduces to the SM, augmented by seesaw generated neutrino masses and
mixing, plus the axion. The latter solves the strong CP problem and accounts
for the cold dark matter in the Universe. The inflaton is comprised by a
mixture of $\sigma$ and the SM Higgs, and reheating of the Universe after
inflation proceeds via the Higgs portal. Baryogenesis occurs via thermal
leptogenesis. Thus, five fundamental problems of particle physics and cosmology
are solved at one stroke in this unified Standard Model - Axion - seesaw -
Higgs portal inflation (SMASH) model. It can be probed decisively by upcoming
cosmic microwave background and axion dark matter experiments.


title: Hamiltonian control of Kuramoto oscillators

abstract:
  Many coordination phenomena are based on a synchronisation process, whose
global behaviour emerges from the interactions among the individual parts.
Often in Nature, such self-organising mechanism allows the system to behave as
a whole and thus grounding its very first existence, or expected functioning,
on such process. There are however cases where synchronisation acts against the
stability of the system; for instance in the case of engineered structures,
resonances among sub parts can destabilise the whole system. In this Letter we
propose an innovative control method to tackle the synchronisation process
based on the use of the Hamiltonian control theory, by adding a small control
term to the system we are able to impede the onset of the synchronisation. We
present our results on the paradigmatic Kuramoto model but the applicability
domain is far more large.


title: Dynamics of ellipsoidal tracers in swimming algal suspensions

abstract:
  Enhanced diffusion of passive tracers immersed in active fluids is a
universal feature of active fluids and has been extensively studied in recent
years. Similar to microrheology for equilibrium complex fluids, the unusual
enhanced particle dynamics reveal intrinsic properties of active fluids.
Nevertheless, previous studies have shown that the translational dynamics of
spherical tracers are qualitatively similar, independent of whether active
particles are pushers or pullers---the two fundamental classes of active
fluids. Is it possible to distinguish pushers from pullers by simply imaging
the dynamics of passive tracers? Here, we investigated the diffusion of
isolated ellipsoids in algal C. reinhardtii suspensions---a model for
puller-type active fluids. In combination with our previous results on
pusher-type E. coli suspensions [Peng et al., Phys. Rev. Lett. 116, 068303
(2016)], we showed that the dynamics of asymmetric tracers show a profound
difference in pushers and pullers due to their rotational degree of freedom.
Although the laboratory-frame translation and rotation of ellipsoids are
enhanced in both pushers and pullers, similar to spherical tracers, the
anisotropic diffusion in the body frame of ellipsoids shows opposite trends in
the two classes of active fluids. An ellipsoid diffuses fastest along its major
axis when immersed in pullers, whereas it diffuses slowest along the major axis
in pushers. This striking difference can be qualitatively explained using a
simple hydrodynamic model. In addition, our study on algal suspensions reveals
that the influence of the near-field advection of algal swimming flows on the
translation and rotation of ellipsoids shows different ranges and strengths.
Our work provides not only new insights into universal organizing principles of
active fluids, but also a convenient tool for detecting the class of active
particles.


title: Learning Protein Dynamics with Metastable Switching Systems

abstract:
  We introduce a machine learning approach for extracting fine-grained
representations of protein evolution from molecular dynamics datasets.
Metastable switching linear dynamical systems extend standard switching models
with a physically-inspired stability constraint. This constraint enables the
learning of nuanced representations of protein dynamics that closely match
physical reality. We derive an EM algorithm for learning, where the E-step
extends the forward-backward algorithm for HMMs and the M-step requires the
solution of large biconvex optimization problems. We construct an approximate
semidefinite program solver based on the Frank-Wolfe algorithm and use it to
solve the M-step. We apply our EM algorithm to learn accurate dynamics from
large simulation datasets for the opioid peptide met-enkephalin and the
proto-oncogene Src-kinase. Our learned models demonstrate significant
improvements in temporal coherence over HMMs and standard switching models for
met-enkephalin, and sample transition paths (possibly useful in rational drug
design) for Src-kinase.


title: A desert of gas giant planets beyond tens of au

abstract:
  Direct imaging observations constrain the fraction of stars orbited by gas
giant planets with separations greater than 10 au to about 0.01 only. This is
widely believed to indicate that massive protoplanetary discs rarely fragment
on planetary mass objects. I use numerical simulations of gas clumps embedded
in massive gas discs to show that these observations are consistent with $\sim
0.2 - 10$ planetary mass clumps per star being born in young gravitationally
unstable discs. A trio of processes -- rapid clump migration, tidal disruption
and runaway gas accretion -- destroys or transforms all of the simulated clumps
into other objects, resulting in a desert of gas giants beyond separation of
approximately 10 au. The cooling rate of the disc controls which of the three
processes is dominant. For cooling rates faster than a few local dynamical
times, clumps always grow rapidly and become massive brown dwarfs or low mass
stars. For longer cooling times, post-collapse (high density) planets migrate
inward to $\sim 10-20$ au where they open a gap in the disc and then continue
to migrate inward much less rapidly. Pre-collapse (low density) planets are
tidally disrupted and may leave massive solid cores behind. Gas giant planets
observed inside the desert, such as those in HR 8799, must have followed an
unusual evolutionary path, e.g., their host disc being dispersed in a
catastrophic fashion.


title: Understanding intermediate layers using linear classifier probes

abstract:
  Neural network models have a reputation for being black boxes. We propose to
monitor the features at every layer of a model and measure how suitable they
are for classification. We use linear classifiers, which we refer to as
"probes", trained entirely independently of the model itself.
  This helps us better understand the roles and dynamics of the intermediate
layers. We demonstrate how this can be used to develop a better intuition about
models and to diagnose potential problems.
  We apply this technique to the popular models Inception v3 and Resnet-50.
Among other things, we observe experimentally that the linear separability of
features increase monotonically along the depth of the model.


title:
Administration Costs in the Management of Research Funds; A Case Study
  of a Public Fund for the Promotion of Industrial Innovation

abstract:
  Research funding agencies routinely use a proportion of their total revenues
to support internal administration and marketing costs. The ratio of
administration to total costs, referred to as the administration ratio, is
highly variable and within any single fund depends on many factors including
the number and average size of projects and the overall efficiency of the
funding agency. In this study, the standard agency activities have been
identified and used to develop a model of administration costs against expected
outcomes. In particular, the model has been designed to estimate the optimum
portfolio success rate and administration ratio as a function of a range of key
input variables including the project size, the complexity of proposal
evaluation and project management, the risk tolerance of the sponsor and the
targeted research domain.


title:
Canonical and symplectic analysis for three dimensional gravity without
  dynamics

abstract:
  In this paper a detailed Hamiltonian analysis of three-dimensional gravity
without dynamics proposed by V. Hussain is performed. We report the complete
structure of the constraints and the Dirac brackets are explicitly computed. In
addition, the Faddeev-Jackiw symplectic approach is developed; we report the
complete set of Faddeev-Jackiw constraints and the generalized brackets, then
we show that the Dirac and the generalized Faddeev-Jackiw brackets coincide to
each other. Finally, the similarities and advantages between Faddeev-Jackiw and
Dirac's formalism are briefly discussed.


title:
Chiral density wave versus pion condensation in the 1+1 dimensional NJL
  model

abstract:
  In this paper, we study the possibility of an inhomogeneous quark condensate
in the 1+1 dimensional Nambu-Jona-Lasinio model in the large-$N_c$ limit at
finite temperature $T$ and quark chemical potential $\mu$ using dimensional
regularization. The phase diagram in the $\mu$--$T$ plane is mapped out. At
zero temperature, an inhomogeneous phase with a chiral-density wave exists for
all values of $\mu>\mu_c$. Performing a Ginzburg-Landau analysis, we show that
in the chiral limit, the critical point and the Lifschitz point coincide. We
also consider the competition between a chiral-density wave and a constant pion
condensate at finite isospin chemical potential $\mu_I$. The phase diagram in
the $\mu_I$--$\mu$ plane is mapped out and shows a rich phase structure.


title:
Pointwise Semi-Slant Warped Product Submanifold in a Lorentzian
  Paracosymplectic Manifold

abstract:
  Recently Y{\"u}ksel et. al. \cite{SY} shows that there doesn't exist any
proper semi-slant warped product submanifolds in a Lorentzian paracosymplectic
manifold. In the present article, we first define and give preparatory lemmas
for a new generalize class of semi-slant submanifolds called pointwise
semi-slant submanifolds in a Lorentzian paracosymplectic manifold, and then we
ensure by presenting some existence results and characterization theorem that
there exist a non-trivial pointwise semi-slant warped product submanifolds in a
Lorentzian paracosymplectic manifold counter to warped product semi-slant
submanifolds in a Lorentzian paracosymplectic manifold.


title:
Compensated Compactness in Banach Spaces and Weak Rigidity of Isometric
  Immersions of Manifolds

abstract:
  We present a compensated compactness theorem in Banach spaces established
recently, whose formulation is originally motivated by the weak rigidity
problem for isometric immersions of manifolds with lower regularity. As a
corollary, a geometrically intrinsic div-curl lemma for tensor fields on
Riemannian manifolds is obtained. Then we show how this intrinsic div-curl
lemma can be employed to establish the global weak rigidity of the
Gauss-Codazzi-Ricci equations, the Cartan formalism, and the corresponding
isometric immersions of Riemannian submanifolds.


title: Index Sets of Universal Codes

abstract:
  We examine sets of codes such that certain properties are invariant under the
choice of oracle from a range of possible oracles and establish a connection
between such codes and Medvedev reductions. In examing the complexity of such
sets of \emph{universal codes}, we prove completeness results at various levels
of the arithmetic hierarchy as well as two general theorems for obtaining
$\Pi_1^1$-completeness for sets of universal codes. Among other corollaries, we
show that the set of codes for Medvedev reductions of bi-immune sets to DNC
functions is $\Pi_1^1$-complete.


title: Optimal mixing enhancement

abstract:
  We introduce a general-purpose method for optimising the mixing rate of
advective fluid flows. An existing velocity field is perturbed in a $C^1$
neighborhood to maximize the mixing rate for flows generated by velocity fields
in this neighborhood. Our numerical approach is based on the infinitesimal
generator of the flow and is solved by standard linear programming methods. The
perturbed flow may be easily constrained to preserve the same steady state
distribution as the original flow, and various natural geometric constraints
can also be simply applied. The same technique can also be used to optimize the
mixing rate of advection-diffusion flow models by manipulating the drift term
in a small neighborhood.


title: Coupling q-deformed dark energy to dark matter

abstract:
  We propose a novel coupled dark energy model which is assumed to occur as a
q-deformed scalar field and investigate whether it will provide an expanding
universe phase. We consider the q-deformed dark energy as coupled to dark
matter inhomogeneities. We perform the phase-space analysis of the model by
numerical methods and find the late-time accelerated attractor solutions. The
attractor solutions imply that the coupled q-deformed dark energy model is
consistent with the conventional dark energy models satisfying an acceleration
phase of universe. At the end, we compare the cosmological parameters of
deformed and standard dark energy models and interpret the implications.


title: Decay Properties of Solutions to a 4-parameter Family of Wave Equations

abstract:
  In this paper, persistence properties of solutions are investigated for a
4-parameter family ($k-abc$ equation) of evolution equations having
$(k+1)$-degree non-linearities and containing as its integrable members the
Camassa-Holm, the Degasperis-Procesi, Novikov and Fokas-Olver-Rosenau-Qiao
equations. These properties will imply that strong solutions of the $k-abc$
equation will decay at infinity in the spatial variable provided that the
initial data does. Furthermore, it is shown that the equation exhibits unique
continuation for appropriate values of the parameters $k$, $a$, $b$, and $c$.


title: New Z(3) strings

abstract:
  We consider a Yang-Mills-Higgs theory with the gauge group SU(3) broken to
its center Z(3) by two scalar fields in the adjoint representation and obtain
new Z(3) strings asymptotic configurations with the gauge field and magnetic
field in the direction of the step operators.


title:
Trump vs. Hillary Analyzing Viral Tweets during US Presidential
  Elections 2016

abstract:
  In this paper, we provide a quantitative and qualitative analyses of the
viral tweets related to the US presidential election. In our study, we focus on
analyzing the most retweeted 50 tweets for everyday during September and
October 2016. The resulting set is composed 3,050 viral tweets, and they were
retweeted over 20.5 million times. We manually annotated the tweets as
favorable of Trump, Clinton, or neither. Our quantitative study shows that
tweets favoring Trump were usually retweeted more than pro-Clinton tweets, with
the exception of a few days in September and two days in October, especially
the day following the first presidential debate and following the release of
the Access Hollywood tape. On two days in October 2016, pro-Trump tweet volume
accounted for than 90\% of the total tweet volume.


title: Trapping Phenomenon Attenuates Tipping Points for Limit Cycles

abstract:
  Nonlinear dynamical systems may be exposed to tipping points, critical
thresholds at which small changes in the external inputs or in the systems
parameters abruptly shift the system to an alternative state with a contrasting
dynamical behavior. While tipping in a fold bifurcation of an equilibrium is
well understood, much less is known about tipping of oscillations (limit
cycles) though this dynamics are the typical response of many natural systems
to a periodic external forcing, like e.g. seasonal forcing in ecology and
climate sciences. We provide a detailed analysis of tipping phenomena in
periodically forced systems and show that, when limit cycles are considered, a
transient structure, so-called channel, plays a fundamental role in the
transition. Specifically, we demonstrate that trajectories crossing such
channel conserve, for a characteristic time, the twisting behavior of the
stable limit cycle destroyed in the fold bifurcation of cycles. As a
consequence, this channel acts like a ghost of the limit cycle destroyed in the
critical transition and instead of the expected abrupt transition we find a
smooth one. This smoothness is also the reason that it is difficult to
precisely determine the transition point employing the usual indicators of
tipping points, like critical slowing down and flickering.