title: Beauville surfaces and probabilistic group theory

abstract:
  A Beauville surface is a complex algebraic surface that can be presented as a
quotient of a product of two curves by a suitable action of a finite group.
Bauer, Catanese and Grunewald have been able to intrinsically characterize the
groups appearing in minimal presentations of Beauville surfaces in terms of the
existence of a so-called "Beauville structure". They conjectured that all
finite simple groups, except A5, admit such a structure. This conjecture has
recently been proved by Guralnick-Malle and Fairbairn-Magaard-Parker.
  In this survey we demonstrate another approach towards the proof of this
conjecture, based on probabilistic group theoretical methods, by describing the
following three works. The first is the work of Garion, Larsen and Lubotzky,
showing that the above conjecture holds for almost all finite simple groups of
Lie type. The second is the work of Garion and Penegini on Beauville structures
of alternating groups, based on results of Liebeck and Shalev, and the third is
the case of the group PSL(2,p^e), in which we give bounds on the probability of
generating a Beauville structure. We also discuss other related problems
regarding finite simple quotients of hyperbolic triangle groups and present
some open questions and conjectures.


title:
A Meta-heuristically Approach of the Spatial Assignment Problem of Human
  Resources in Multi-sites Enterprise

abstract:
  The aim of this work is to present a meta-heuristically approach of the
spatial assignment problem of human resources in multi-sites enterprise.
Usually, this problem consists to move employees from one site to another based
on one or more criteria. Our goal in this new approach is to improve the
quality of service and performance of all sites with maximizing an objective
function under some managers imposed constraints. The formulation presented
here of this problem coincides perfectly with a Combinatorial Optimization
Problem (COP) which is in the most cases NP-hard to solve optimally. To avoid
this difficulty, we have opted to use a meta-heuristic popular method, which is
the genetic algorithm, to solve this problem in concrete cases. The results
obtained have shown the effectiveness of our approach, which remains until now
very costly in time. But the reduction of the time can be obtained by different
ways that we plan to do in the next work.


title: On the gauge symmetries of Maxwell-like higher-spin Lagrangians

abstract:
  In their simplest form, metric-like Lagrangians for higher-spin massless
fields display constrained gauge symmetries, unless auxiliary fields are
introduced or locality is foregone. Specifically, in its standard incarnation,
gauge invariance of Maxwell-like Lagrangians relies on parameters with
vanishing divergence. We propose an alternative form of the corresponding local
symmetry involving unconstrained parameters of mixed-symmetry type, described
by rectangular two-row Young diagrams and entering high-derivative gauge
transformations. The resulting gauge algebra appears to be reducible and we
display the full pattern of gauge-for-gauge parameters, testing its correctness
via the corresponding counting of degrees of freedom. Incidentally, this shows
that massless higher spins admit a local unconstrained formulation with no need
for auxiliary fields.


title:
Exchange bias associated with phase separation in the Nd2/3Ca1/3MnO3
  manganite

abstract:
  The exchange bias (EB) phenomenon has been found in Nd2/3Ca1/3MnO3
perovskite. The phenomenon manifests itself as a negative horizontal shift of
magnetization hysteresis loops. The EB phenomenon is evident of an interface
exchange coupling between coexisting antiferromagnetic (AFM) and ferromagnetic
(FM) phases and confirms the phase separated state of the compound at low
temperatures. The EB effect is found to be strongly dependent on the cooling
magnetic field and the temperature, which is associated with the evolution of
spontaneous AFM - FM phase separated state of the compound. Analysis of
magnetic hysteresis loops has shown that ferromagnetic moment $M_{FM}$
originating from the FM clusters saturates in a relatively low magnetic field
about H ~ 0.4T. The obtained saturation value $M_{FM}$(1T) ~ 0.45$\mu_{B}$ is
in a good agreement with our previous neutron diffraction data.


title:
Effective Data Aggregation Scheme for Large-scale Wireless Sensor
  Networks

abstract:
  Energy preservation is one of the most important challenges in wireless
sensor networks. In most applications, sensor networks consist of hundreds or
thousands nodes that are dispersed in a wide field. Hierarchical architectures
and data aggregation methods are increasingly gaining more popularity in such
large-scale networks. In this paper, we propose a novel adaptive
Energy-Efficient Multi-layered Architecture (EEMA) protocol for large-scale
sensor networks, wherein both hierarchical architecture and data aggregation
are efficiently utilized. EEMA divides the network into some layers as well as
each layer into some clusters, where the data are gathered in the first layer
and are recursively aggregated in upper layers to reach the base station. Many
criteria are wisely employed to elect head nodes, including the residual
energy, centrality, and proximity to bottom-layer heads. The routing delay is
mathematically analyzed. Performance evaluation is performed via simulations
which confirms the effectiveness of the proposed EEMA protocol in terms of the
network lifetime and reduced routing delay.


title:
Slow protein fluctuations explain the emergence of growth phenotypes and
  persistence in clonal bacterial populations

abstract:
  One of the most challenging problems in microbiology is to understand how a
small fraction of microbes that resists killing by antibiotics can emerge in a
population of genetically identical cells, the phenomenon known as persistence
or drug tolerance. Its characteristic signature is the biphasic kill curve,
whereby microbes exposed to a bactericidal agent are initially killed very
rapidly but then much more slowly. Here we relate this problem to the more
general problem of understanding the emergence of distinct growth phenotypes in
clonal populations. We address the problem mathematically by adopting the
framework of the phenomenon of so-called weak ergodicity breaking, well known
in dynamical physical systems, which we extend to the biological context. We
show analytically and by direct stochastic simulations that distinct growth
phenotypes can emerge as a consequence of slow-down of stochastic fluctuations
in the expression of a gene controlling growth rate. In the regime of fast gene
transcription, the system is ergodic, the growth rate distribution is unimodal,
and accounts for one phenotype only. In contrast, at slow transcription and
fast translation, weakly non-ergodic components emerge, the population
distribution of growth rates becomes bimodal, and two distinct growth
phenotypes are identified. When coupled to the well-established growth rate
dependence of antibiotic killing, this model describes the observed fast and
slow killing phases, and reproduces much of the phenomenology of bacterial
persistence. The model has major implications for efforts to develop control
strategies for persistent infections.


title: Neutron-Antineutron Oscillations: A Snowmass 2013 White Paper

abstract:
  This paper summarizes discussions of the theoretical developments and the
studies performed by the NNbarX collaboration for the 2013 Snowmass Community
Summer Study.


title:
Single-shot 3D structure determination of nanocrystals with femtosecond
  X-ray free electron laser pulses

abstract:
  Coherent diffraction imaging (CDI) using synchrotron radiation, X-ray free
electron lasers (X-FELs), high harmonic generation, soft X-ray lasers, and
optical lasers has found broad applications across several disciplines. An
active research direction in CDI is to determine the structure of single
particles with intense, femtosecond X-FEL pulses based on
diffraction-before-destruction scheme. However, single-shot 3D structure
determination has not been experimentally realized yet. Here we report the
first experimental demonstration of single-shot 3D structure determination of
individual nanocrystals using ~10 femtosecond X-FEL pulses. Coherent
diffraction patterns are collected from high-index-faceted nanocrystals, each
struck by a single X-FEL pulse. Taking advantage of the symmetry of the
nanocrystal, we reconstruct the 3D structure of each nanocrystal from a
single-shot diffraction pattern at ~5.5 nm resolution. As symmetry exists in
many nanocrystals and virus particles, this method can be applied to 3D
structure studies of such particles at nanometer resolution on femtosecond time
scales.


title: Quasiregular ellipticity of open and generalized manifolds

abstract:
  We study the existence of geometrically controlled branched covering maps
from $\mathbb R^3$ to open $3$-manifolds or to decomposition spaces $\mathbb
S^3/G$, and from $\mathbb S^3/G$ to $\mathbb S^3$.


title:
The Gregory-Laflamme instability and non-uniform generalizations of NUT
  strings

abstract:
  We explore via linearized perturbation theory the Gregory-Laflamme
instability of the NUT string (i.e the D=4 Lorentzian NUT solution uplifted to
five dimensions). Our results indicate that the Gregory-Laflamme instability
persists in the presence of a NUT charge $n$, the critical length of the
extra-dimension increasing with $n$ for the same value of mass. The non-uniform
branch of NUT strings is numerically extended into the full nonlinear regime.


title:
Search for $C=+$ charmonium states in $e^+e^-\to \gamma+~X$ at
  BEPCII/BESIII

abstract:
  We extend our original study in Ref. [1] on the production of $C=+$
charmonium states $X=\eta_c(1S/2S)$ and $\chi_{cJ}(1P/2P)$ in
$e^+e^-\to\gamma~+~X$ at B factories to the BEPCII/BESIII energy region with
$\sqrt{s}=4.0\mbox{-}5.0$ GeV. In the framework of nonrelativistic QCD
factorization, the cross sections are estimated to be as large as
$0.1\mbox{-}0.9$ pb. The results could be used to search for the missing $2P$
charmonium states or to estimate the continuum backgrounds in the resonance
region.


title: Mode-coupling points to functionally important residues in Myosin II

abstract:
  Relevance of mode coupling to energy/information transfer during protein
function, particularly in the context of allosteric interactions is widely
accepted. However, existing evidence in favor of this hypothesis comes
essentially from model systems. We here report a novel formal analysis of the
near-native dynamics of myosin II, which allows us to explore the impact of the
interaction between possibly non-Gaussian vibrational modes on fluctutational
dynamics. We show that, an information-theoretic measure based on mode coupling
{\it alone} yields a ranking of residues with a statistically significant bias
favoring the functionally critical locations identified by experiments on
myosin II.


title: Information Compression, Intelligence, Computing, and Mathematics

abstract:
  This paper presents evidence for the idea that much of artificial
intelligence, human perception and cognition, mainstream computing, and
mathematics, may be understood as compression of information via the matching
and unification of patterns. This is the basis for the "SP theory of
intelligence", outlined in the paper and fully described elsewhere. Relevant
evidence may be seen: in empirical support for the SP theory; in some
advantages of information compression (IC) in terms of biology and engineering;
in our use of shorthands and ordinary words in language; in how we merge
successive views of any one thing; in visual recognition; in binocular vision;
in visual adaptation; in how we learn lexical and grammatical structures in
language; and in perceptual constancies. IC via the matching and unification of
patterns may be seen in both computing and mathematics: in IC via equations; in
the matching and unification of names; in the reduction or removal of
redundancy from unary numbers; in the workings of Post's Canonical System and
the transition function in the Universal Turing Machine; in the way computers
retrieve information from memory; in systems like Prolog; and in the
query-by-example technique for information retrieval. The chunking-with-codes
technique for IC may be seen in the use of named functions to avoid repetition
of computer code. The schema-plus-correction technique may be seen in functions
with parameters and in the use of classes in object-oriented programming. And
the run-length coding technique may be seen in multiplication, in division, and
in several other devices in mathematics and computing. The SP theory resolves
the apparent paradox of "decompression by compression". And computing and
cognition as IC is compatible with the uses of redundancy in such things as
backup copies to safeguard data and understanding speech in a noisy
environment.


title: Information and the foundations of quantum theory

abstract:
  We believe that the hypothesis `it from bit' originates from the assumption
that probabilities have a fundamental, irremovable status in quantum theory. We
argue against this assumption and highlight four well-known reformulations /
modifications of the theory in which probabilities and the measuring apparatus
do not play a fundamental role. These are: Bohmian Mechanics, Dynamical
Collapse Models, Trace Dynamics, and Quantum Theory without Classical Time.
Here the `it' is primary and the `bit' is derived from the `it'.


title: Non-relativistic approach for cosmological Scalar Field Dark Matter

abstract:
  We derive non-relativistic equations of motion for the formation of
cosmological structure in a Scalar Field Dark Matter (SFDM) model corresponding
to a complex scalar field endowed with a quadratic scalar potential. Starting
with the full equations of motion written in the Newtonian gauge of scalar
perturbations, we separate out the fields involved into relativistic and
non-relativistic parts, and find the equations of motion for the latter that
can be used to build up the full solution. One important assumption will also
be that the SFDM field is in the regime of fast oscillations, under which its
behavior is exactly that of cold dark matter. The resultant equations are quite
similar to the Schr\"odinger-Poisson system of Newtonian boson stars plus
relativistic leftovers. We exploit that similarity to show how to simulate,
with minimum numerical effort, the formation of cosmological structure in SFDM
models and others alike, and ultimately prove their viability as complete dark
matter models.


title: Worldsheet factorization for twistor-strings

abstract:
  We study the multiparticle factorization properties of two worldsheet
theories which--at tree-level--describe the scattering of massless particles in
four dimensions: the Berkovits-Witten twistor-string for N=4 super-Yang-Mills
coupled to N=4 conformal supergravity, and the Skinner twistor-string for N=8
supergravity. By considering these string-like theories, we can study
factorization at the level of the worldsheet before any Wick contractions or
integrals have been performed; this is much simpler than considering the
factorization properties of the amplitudes themselves. In Skinner's
twistor-string this entails the addition of worldsheet gravity as well as a
formalism that represents all external states in a manifestly symmetric way,
which we develop explicitly at genus zero. We confirm that the scattering
amplitudes of Skinner's theory, as well as the gauge theory amplitudes for the
planar sector of the Berkovits-Witten theory, factorize appropriately at genus
zero. In the non-planar sector, we find behavior indicative of conformal
gravity in the Berkovits-Witten twistor-string. We contrast factorization in
twistor-strings with the story in ordinary string theory, and also make some
remarks on higher genus factorization and disconnected prescriptions.


title: Performance Studies of a Micromegas Chamber in the ATLAS Environment

abstract:
  Five small prototype micromegas detectors were positioned in the ATLAS
detector during Large Hadron Collider running at $\sqrt{s} = 7$ and $8\,
\mathrm{TeV}$. A $9\times 4.5\, \mathrm{cm^2}$ double drift gap detector was
placed in front of the electromagnetic calorimeter and four $9\times 10\,
\mathrm{cm^2}$ detectors on the ATLAS Small Wheel, the first station of the
forward muon spectrometer. The one attached to the calorimeter was exposed to
interaction rates of about $70\,\mathrm{kHz}/\mathrm{cm^2}$ at
$\mathcal{L}=5\times 10^{33}\,\mathrm{cm^{-2}s^{-1}}$ two orders of magnitude
higher than the rates in the Small Wheel. We present the results from
performance studies carried out using data collected with these detectors and
we also compare the currents drawn by the detector installed in front of the
electromagnetic calorimeter with the luminosity measurement in ATLAS.


title:
Modeling catastrophic deaths using EVT with a microsimulation approach
  to reinsurance pricing

abstract:
  Recently, a marked Poisson process (MPP) model for life catastrophe risk was
proposed in [6]. We provide a justification and further support for the model
by considering more general Poisson point processes in the context of extreme
value theory (EVT), and basing the choice of model on statistical tests and
model comparisons. A case study examining accidental deaths in the Finnish
population is provided.
  We further extend the applicability of the catastrophe risk model by
considering small and big accidents separately; the resulting combined MPP
model can flexibly capture the whole range of accidental death counts. Using
the proposed model, we present a simulation framework for pricing (life)
catastrophe reinsurance, based on modeling the underlying policies at
individual contract level. The accidents are first simulated at population
level, and their effect on a specific insurance company is then determined by
explicitly simulating the resulting insured deaths. The proposed
microsimulation approach can potentially lead to more accurate results than the
traditional methods, and to a better view of risk, as it can make use of all
the information available to the re/insurer and can explicitly accommodate even
complex re/insurance terms and product features. As an example we price several
excess reinsurance contracts. The proposed simulation model is also suitable
for solvency assessment.


title:
Commensurating endomorphisms of acylindrically hyperbolic groups and
  applications

abstract:
  We prove that the outer automorphism group $Out(G)$ is residually finite when
the group $G$ is virtually compact special (in the sense of Haglund and Wise)
or when $G$ is isomorphic to the fundamental group of some compact
$3$-manifold.
  To prove these results we characterize commensurating endomorphisms of
acylindrically hyperbolic groups. An endomorphism $\phi$ of a group $G$ is said
to be commensurating, if for every $g \in G$ some non-zero power of $\phi(g)$
is conjugate to a non-zero power of $g$. Given an acylindrically hyperbolic
group $G$, we show that any commensurating endomorphism of $G$ is inner modulo
a small perturbation. This generalizes a theorem of Minasyan and Osin, which
provided a similar statement in the case when $G$ is relatively hyperbolic. We
then use this result to study pointwise inner and normal endomorphisms of
acylindrically hyperbolic groups.


title: Totally Geodesic Submanifolds in Tangent Bundle with g - natural Metric

abstract:
  In the paper we investigate submanifolds in a tangent bundle endowed with
g-natural metric G, defined by a vector field on a base manifold. We give a
sufficient condition for a vector field on M to defined totally geodesic
submanifold in (TM,G). The parallel vector field is discussed in more detail.


title: Physics of non-dissipative ultrarelativistic photospheres

abstract:
  Recent observations, especially by the Fermi satellite, point out the
importance of the thermal component in GRB spectra. This fact revives strong
interest in photospheric emission from relativistic outflows. Early studies
already suggested that the observed spectrum of photospheric emission from
relativistically moving objects differs in shape from the Planck spectrum.
However, this component appears to be subdominant in many GRBs and the origin
of the dominant component is still unclear. One of the popular ideas is that
energy dissipation near the photosphere may produce a non-thermal spectrum and
account for such emission. Before considering such models, though, one has to
determine precise spectral and timing characteristics of the photospheric
emission in the simplest possible case. Hence this paper focuses on various
physical effects which make the photospheric emission spectrum different from
the black body spectrum and quantifies them.


title: Lorentzian Coxeter systems and Boyd-Maxwell ball packings

abstract:
  In the recent study of infinite root systems, fractal patterns of ball
packings were observed while visualizing roots in affine space. In this paper,
we show that the observed fractals are exactly the ball packings described by
Boyd and Maxwell. This correspondence is a corollary of a more fundamental
result: Given a geometric representation of a Coxeter group in a Lorentz space,
the set of limit directions of weights equals the set of limit roots.
Additionally, we use Coxeter complexes to describe tangency graphs of the
corresponding Boyd--Maxwell ball packings. Finally, we enumerate all the
Coxeter systems that generate Boyd-Maxwell ball packings.


title: Floer cohomology of $\mathfrak{g}$-equivariant Lagrangian branes

abstract:
  Building on Seidel-Solomon's fundamental work, we define the notion of a
$\mathfrak{g}$-equivariant Lagrangian brane in an exact symplectic manifold $M$
where $\mathfrak{g} \subset SH^1(M)$ is a sub-Lie algebra of the symplectic
cohomology of $M$. When $M$ is a (symplectic) mirror to an (algebraic)
homogeneous space $G/P$, homological mirror symmetry predicts that there is an
embedding of $\mathfrak{g}$ in $SH^1(M)$. This allows us to study a mirror
theory to classical constructions of Borel-Weil and Bott. We give explicit
computations recovering all finite dimensional irreducible representations of
$\mathfrak{sl}_2$ as representations on the Floer cohomology of an
$\mathfrak{sl}_2$-equivariant Lagrangian brane and discuss generalizations to
arbitrary finite-dimensional semisimple Lie algebras.


title: Increasing lifetimes and the growing saddles of shear flow turbulence

abstract:
  In linearly stable shear flows turbulence spontaneously decays with a
characteristic lifetime that varies with Reynolds number. The lifetime sharply
increases with Reynolds number so that a possible divergence marking the
transition to sustained turbulence at a critical point has been discussed. We
present a mechanism by which the lifetimes increase: in the system's state
space, turbulent motion is supported by a chaotic saddle. Inside this saddle a
locally attracting periodic orbit is created and undergoes a traditional
bifurcation sequence generating chaos. The formed new 'turbulent bubble' is
initially an attractor supporting persistent chaotic dynamics. Soon after its
creation it collides with its own boundary, by which it becomes leaky and
dynamically connected with the surrounding structures. The complexity of the
chaotic saddle that supports transient turbulence hence increases by
incorporating the remnant of a new bubble. As a a result, the time it takes for
a trajectory to leave the saddle and decay to the laminar state is increased.
We demonstrate this phenomenon in plane Couette flow and show that
characteristic lifetimes vary non-smoothly and non-monotonically with Reynolds
number.


title:
On the energy behavior of locally self-similar blowup for the Euler
  equation

abstract:
  In this note we study locally self-similar blow up for the Euler equation.
The main result states that under a mild $L^p$-growth assumption on the profile
$v$, namely, $\int_{|y| \sim L} |v|^p dy \lesssim L^{\g}$ for some $\g <p-2$,
the self-similar solution carries a positive amount of energy up to the time of
blow-up $T$, namely, $\int_{|y| \sim L} |v|^2 dy \sim L^{N-2\a}$. The result
implies and extends several previously known exclusion criteria. It also
supports a general conjecture relating fractal local dimensions of the energy
measure with the rate of velocity growth at the time of possible blowup.


title:
Nonlinear unmixing of hyperspectral images using a semiparametric model
  and spatial regularization

abstract:
  Incorporating spatial information into hyperspectral unmixing procedures has
been shown to have positive effects, due to the inherent spatial-spectral
duality in hyperspectral scenes. Current research works that consider spatial
information are mainly focused on the linear mixing model. In this paper, we
investigate a variational approach to incorporating spatial correlation into a
nonlinear unmixing procedure. A nonlinear algorithm operating in reproducing
kernel Hilbert spaces, associated with an $\ell_1$ local variation norm as the
spatial regularizer, is derived. Experimental results, with both synthetic and
real data, illustrate the effectiveness of the proposed scheme.


title: Convergence of Monte Carlo Tree Search in Simultaneous Move Games

abstract:
  We study Monte Carlo tree search (MCTS) in zero-sum extensive-form games with
perfect information and simultaneous moves. We present a general template of
MCTS algorithms for these games, which can be instantiated by various selection
methods. We formally prove that if a selection method is $\epsilon$-Hannan
consistent in a matrix game and satisfies additional requirements on
exploration, then the MCTS algorithm eventually converges to an approximate
Nash equilibrium (NE) of the extensive-form game. We empirically evaluate this
claim using regret matching and Exp3 as the selection methods on randomly
generated games and empirically selected worst case games. We confirm the
formal result and show that additional MCTS variants also converge to
approximate NE on the evaluated games.


title: Fermi Pulsars and the Cosmic Ray Knee

abstract:
  Nuclei, if lifted into the radiation zone of a weak axisymmetric pulsar, are
accelerated to quasi-monoenergetic spectrum, with more than half of the nuclear
luminosity emitted nearly monoenergetically, at the energy E approximately =
4Ze(L/c)^(1/2), where L is the spin-down power.
  With a number of (not obviously wrong) assumptions, this turns Fermi (-like)
weak pulsars into prominent accelerators at energies near the cosmic ray knee.
The main uncertainty is purely theoretical: one needs to understand if nuclei
are major positive charge carries in some weak pulsar magnetospheres.


title: Diffusion LMS for clustered multitask networks

abstract:
  Recent research works on distributed adaptive networks have intensively
studied the case where the nodes estimate a common parameter vector
collaboratively. However, there are many applications that are
multitask-oriented in the sense that there are multiple parameter vectors that
need to be inferred simultaneously. In this paper, we employ diffusion
strategies to develop distributed algorithms that address clustered multitask
problems by minimizing an appropriate mean-square error criterion with
$\ell_2$-regularization. Some results on the mean-square stability and
convergence of the algorithm are also provided. Simulations are conducted to
illustrate the theoretical findings.


title: Low dimensionality of the diamond surface conductivity

abstract:
  Undoped diamond, a remarkable bulk electrical insulator, exhibits a high
surface conductivity in air when the surface is hydrogen-terminated. Although
theoretical models have claimed that a two-dimensional hole gas is established
as a result of surface energy band bending, no definitive experimental
demonstration has been reported so far. Here, we prove the two-dimensional
character of the surface conductivity by low temperature characterization of
diamond in-plane gated field-effect transistors that enable the lateral
confinement of the transistor's drain-source channel to nanometer dimensions.
In these devices, we observe Coulomb blockade effects of multiple quantum
islands varying in size with the gate voltage. The charging energy and thus the
size of these zero-dimensional islands exhibits a gate voltage dependence which
is the direct result of the two-dimensional character of the conductive channel
formed at hydrogen-terminated diamond surfaces.


title: Constraining the WMAP9 bispectrum and trispectrum with needlets

abstract:
  We develop a needlet approach to estimate the amplitude of general (including
non-separable) bispectra and trispectra in the cosmic microwave background, and
apply this to the WMAP 9-year data. We obtain estimates for the `orthogonal'
bispectrum mode, yielding results which are consistent with the WMAP 7-year
data. We do not observe the frequency-dependence suggested by the WMAP team's
analysis of the 9-year data. We present 1-$\sigma$ constraints on the `local'
trispectrum shape $\gnl/10^5= -4.1\pm 2.3$, the `$c1$' equilateral model
$\gnl^{c_1}/10^6= -0.8\pm 2.9$, and the constant model $\gnl^{\rm{const}}/10^6=
-0.2\pm 1.8$, together with a $95\%$ confidence-level upper bound on the
multifield local parameter $\taunl<22000$. We estimate the bias on these
parameters produced by point sources. The techniques developed in this paper
should prove useful for other datasets such as Planck.


title: Convergence analysis of kernel LMS algorithm with pre-tuned dictionary

abstract:
  The kernel least-mean-square (KLMS) algorithm is an appealing tool for online
identification of nonlinear systems due to its simplicity and robustness. In
addition to choosing a reproducing kernel and setting filter parameters,
designing a KLMS adaptive filter requires to select a so-called dictionary in
order to get a finite-order model. This dictionary has a significant impact on
performance, and requires careful consideration. Theoretical analysis of KLMS
as a function of dictionary setting has rarely, if ever, been addressed in the
literature. In an analysis previously published by the authors, the dictionary
elements were assumed to be governed by the same probability density function
of the input data. In this paper, we modify this study by considering the
dictionary as part of the filter parameters to be set. This theoretical
analysis paves the way for future investigations on KLMS dictionary design.


title:
The age specific incidence anomaly suggests that cancers originate
  during development

abstract:
  Cancers are caused by the accumulation of genetic alterations. Since this
accumulation takes time, the incidence of most cancers is thought to increase
exponentially with age. However, careful measurements of the age-specific
incidence shows that the specific incidence for many forms of cancer rises with
age to a maximum, then decreases. This decrease in the age-specific incidence
with age is an anomaly. Understanding this anomaly should lead to a better
understanding of how tumors develop and grow. Here I derive the shape of the
age-specific incidence, showing that it should follow the shape of a Weibull
distribution. Measurements indicate that the age-specific incidence for colon
cancer does indeed follow a Weibull distribution. This analysis leads to the
interpretation that for colon cancer two sub-populations exist in the general
population: a susceptible population and an immune population. Colon tumors
will only occur in the susceptible population. This analysis is consistent with
the developmental origins of disease hypothesis and generalizable to many other
common forms of cancer.


title:
Distributed Control of Networked Dynamical Systems: Static Feedback,
  Integral Action and Consensus

abstract:
  This paper analyzes distributed control protocols for first- and second-order
networked dynamical systems. We propose a class of nonlinear consensus
controllers where the input of each agent can be written as a product of a
nonlinear gain, and a sum of nonlinear interaction functions. By using integral
Lyapunov functions, we prove the stability of the proposed control protocols,
and explicitly characterize the equilibrium set. We also propose a distributed
proportional-integral (PI) controller for networked dynamical systems. The PI
controllers successfully attenuate constant disturbances in the network. We
prove that agents with single-integrator dynamics are stable for any integral
gain, and give an explicit tight upper bound on the integral gain for when the
system is stable for agents with double-integrator dynamics. Throughout the
paper we highlight some possible applications of the proposed controllers by
realistic simulations of autonomous satellites, power systems and building
temperature control.


title:
Dark Matter in the Coming Decade: Complementary Paths to Discovery and
  Beyond

abstract:
  In this Report we discuss the four complementary searches for the identity of
dark matter: direct detection experiments that look for dark matter interacting
in the lab, indirect detection experiments that connect lab signals to dark
matter in our own and other galaxies, collider experiments that elucidate the
particle properties of dark matter, and astrophysical probes sensitive to
non-gravitational interactions of dark matter. The complementarity among the
different dark matter searches is discussed qualitatively and illustrated
quantitatively in several theoretical scenarios. Our primary conclusion is that
the diversity of possible dark matter candidates requires a balanced program
based on all four of those approaches.

categories: hep-ph astro-ph.CO astro-ph.HE astro-ph.IM hep-ex


title: Selective covering properties of product spaces, II: gamma spaces

abstract:
  We study productive properties of gamma spaces, and their relation to other,
classic and modern, selective covering properties. Among other things, we prove
the following results:
  1. Solving a problem of F. Jordan, we show that for every unbounded tower set
of reals X of cardinality aleph_1, the space Cp(X) is productively FU. In
particular, the set X is productively gamma.
  2. Solving problems of Scheepers and Weiss, and proving a conjecture of
Babinkostova-Scheepers, we prove that, assuming CH, there are gamma spaces
whose product is not even Menger.
  3. Solving a problem of Scheepers-Tall, we show that the properties gamma and
Gerlits--Nagy (*) are preserved by Cohen forcing. Moreover, every Hurewicz
space that Remains Hurewicz in a Cohen extension must be Rothberger (and thus
(*)).
  We apply our results to solve a large number of additional problems, and use
Arhangel'skii duality to obtain results concerning local properties of function
spaces and countable topological groups.


title: Sign changes of Kloosterman sums with almost prime moduli

abstract:
  We prove that the Kloosterman sum $S(1,1;c)$ can change sign infinitely often
as $c$ runs over squarefree moduli with at most 10 prime factors, which
improves the previous results of E. Fouvry and Ph. Michel, J. Sivak-Fischler
and K. Matom\"{a}ki, replacing 10 by 23, 18 and 15, respectively. The method
combines the Selberg sieve, equidistribution of Kloosterman sums and spectral
theory of automorphic forms.


title:
Selective reflection technique as a probe to monitor the growth of a
  metallic thin film on dielectric surfaces

abstract:
  Controlling thin film formation is technologically challenging. The knowledge
of physical properties of the film and of the atoms in the surface vicinity can
help improve control over the film growth. We investigate the use of the
well-established selective reflection technique to probe the thin film during
its growth, simultaneously monitoring the film thickness, the atom-surface van
der Waals interaction and the vapor properties in the surface vicinity.


title: Least quantile regression via modern optimization

abstract:
  We address the Least Quantile of Squares (LQS) (and in particular the Least
Median of Squares) regression problem using modern optimization methods. We
propose a Mixed Integer Optimization (MIO) formulation of the LQS problem which
allows us to find a provably global optimal solution for the LQS problem. Our
MIO framework has the appealing characteristic that if we terminate the
algorithm early, we obtain a solution with a guarantee on its sub-optimality.
We also propose continuous optimization methods based on first-order
subdifferential methods, sequential linear optimization and hybrid combinations
of them to obtain near optimal solutions to the LQS problem. The MIO algorithm
is found to benefit significantly from high quality solutions delivered by our
continuous optimization based methods. We further show that the MIO approach
leads to (a) an optimal solution for any dataset, where the data-points
$(y_i,\mathbf{x}_i)$'s are not necessarily in general position, (b) a simple
proof of the breakdown point of the LQS objective value that holds for any
dataset and (c) an extension to situations where there are polyhedral
constraints on the regression coefficient vector. We report computational
results with both synthetic and real-world datasets showing that the MIO
algorithm with warm starts from the continuous optimization methods solve small
($n=100$) and medium ($n=500$) size problems to provable optimality in under
two hours, and outperform all publicly available methods for large-scale
($n={}$10,000) LQS problems.


title: Linear Corotation Torques in Non-Barotropic Disks

abstract:
  I derive a fully analytic expression for the linear corotation torque to
first order in eccentricity for planets in non-barotropic protoplanetary disks,
taking into account the effect of disk entropy gradients. This torque formula
is applicable to both the co-orbital corotation torque and the non co-orbital
corotation torques -- for planets in orbits with non-zero eccentricity -- in
disks where the thermal diffusivity and viscosity are sufficient to maintain
linearity of these interactions. While the co-orbital corotation torque is
important for migration of planets in Type I migration, the non co-orbital
corotation torque plays an important role in the eccentricity evolution of
giant planets that have opened gaps in the disk. The presence of an entropy
gradient in the disk can significantly modify the corotation torque in both
these cases.


title:
Shedding Light on the Eccentricity Valley: Gap Heating and Eccentricity
  Excitation of Giant Planets in Protoplanetary Disks

abstract:
  We show that the first order (non co-orbital) corotation torques are
significantly modified by entropy gradients in a non-barotropic protoplanetary
disk. Such non-barotropic torques can dramatically alter the balance that, for
barotropic cases, results in the net eccentricity damping for giant
gap-clearing planets embedded in the disk. We demonstrate that stellar
illumination can heat the gap enough for the planet's orbital eccentricity to
instead be excited. We also discuss the "Eccentricity Valley" noted in the
known exoplanet population, where low-metallicity stars have a deficit of
eccentric planets between $\sim 0.1$ and $\sim 1$ AU compared to metal-rich
systems (Dawson & Murray-Clay 2013). We show that this feature in the planet
distribution may be due to the self-shadowing of the disk by a rim located at
the dust sublimation radius $\sim 0.1$ AU, which is known to exist for several
T Tauri systems. In the shadowed region between $\sim 0.1$ and $\sim 1$ AU lack
of gap insolation allows disk interactions to damp eccentricity. Outside such
shadowed regions stellar illumination can heat the planetary gaps and drive
eccentricity growth for giant planets. We suggest that the self-shadowing does
not arise at higher metallicity due to the increased optical depth of the gas
interior to the dust sublimation radius.


title: Measurement of the $W$ boson mass with the D0 detector

abstract:
  We give a detailed description of the measurement of the $W$ boson mass,
$M_W$, performed on an integrated luminosity of 4.3 fb$^{-1}$, which is based
on similar techniques as used for our previous measurement done on an
independent data set of 1 fb$^{-1}$ of data. The data were collected using the
D0 detector at the Fermilab Tevatron Collider. This data set yields $1.68\times
10^6$ $W\rightarrow e\nu$ candidate events. We measure the mass using the
transverse mass, electron transverse momentum, and missing transverse energy
distributions. The $M_W$ measurements using the transverse mass and the
electron transverse momentum distributions are the most precise of these three
and are combined to give $M_W$ = 80.367 $\pm$ 0.013 (stat) $\pm$ 0.022 (syst)
GeV = 80.367 $\pm$ 0.026 GeV. When combined with our earlier measurement on 1
fb$^{-1}$ of data, we obtain $M_W$ = 80.375 $\pm$ 0.023 GeV.


title:
Lower bounds on high-temperature diffusion constants from quadratically
  extensive almost conserved operators

abstract:
  We prove a general theorem which provides a strict lower bound on
high-temperature Green-Kubo diffusion constants in locally interacting quantum
lattice systems, under the assumption of existence of a quadratically extensive
almost conserved quantity - an operator whose commutator with the lattice
Hamiltonian is localized on the boundary sites only. We explicitly demonstrate
and compute such a bound in two important models in one dimension, namely in
the (isotropic) Heisenberg spin 1/2 chain and in the fermionic Hubbard chain.

categories: cond-mat.stat-mech cond-mat.str-el math-ph math.MP quant-ph


title: Fringe Field Effects on Bending Magnets, Derived for TRANSPORT/TURTLE

abstract:
  A realistic magnetic dipole has complex effects on a charged particle near
the entrance and exit of the magnet, even with a constant and uniform magnetic
field deep within the interior of the magnet. To satisfy Maxwell's equations,
the field lines near either end of a realistic magnet are significantly more
complicated, yielding non-trivial forces. The effects of this fringe field are
calculated to first order, applying both the paraxial and thin lens
approximations. We find that, in addition to zeroth order effects, the position
of a particle directly impacts the forces in the horizontal and vertical
directions.


title: Optimal Impartial Selection

abstract:
  We study the problem of selecting a member of a set of agents based on
impartial nominations by agents from that set. The problem was studied
previously by Alon et al. and Holzman and Moulin and has important applications
in situations where representatives are selected from within a group or where
publishing or funding decisions are made based on a process of peer review. Our
main result concerns a randomized mechanism that in expectation awards the
prize to an agent with at least half the maximum number of nominations. Subject
to impartiality, this is best possible.


title: Electromagnetic Currents from Electroweak Fermion Level Crossing

abstract:
  Spectral flow of chiral fermions in the background of electroweak sphalerons
is studied. A fermion field configuration that interpolates between the
sphaleron zero mode and the asymptotic fermion modes is proposed for the level
crossing left handed fermion fields. It is shown that the fermionic
electromagnetic currents with non-trivial helicity are produced during the
level crossing. Cosmic magnetic field generation due to these currents is
briefly discussed.


title:
Sparse and Efficient Estimation for Partial Spline Models with
  Increasing Dimension

abstract:
  We consider model selection and estimation for partial spline models and
propose a new regularization method in the context of smoothing splines. The
regularization method has a simple yet elegant form, consisting of roughness
penalty on the nonparametric component and shrinkage penalty on the parametric
components, which can achieve function smoothing and sparse estimation
simultaneously. We establish the convergence rate and oracle properties of the
estimator under weak regularity conditions. Remarkably, the estimated
parametric components are sparse and efficient, and the nonparametric component
can be estimated with the optimal rate. The procedure also has attractive
computational properties. Using the representer theory of smoothing splines, we
reformulate the objective function as a LASSO-type problem, enabling us to use
the LARS algorithm to compute the solution path. We then extend the procedure
to situations when the number of predictors increases with the sample size and
investigate its asymptotic properties in that context. Finite-sample
performance is illustrated by simulations.


title:
Trade-offs drive resource specialization and the gradual establishment
  of ecotypes

abstract:
  Speciation is driven by many different factors. Among those are trade-offs
between different ways an organism utilizes resources, and these trade-offs can
constrain the manner in which selection can optimize traits. Limited migration
among allopatric populations and species interactions can also drive
speciation, but here we ask if trade-offs alone are sufficient to drive
speciation in the absence of other factors. We present a model to study the
effects of trade-offs on specialization and adaptive radiation in asexual
organisms based solely on competition for limiting resources, where trade-offs
are stronger the greater an organism's ability to utilize resources. In this
model resources are perfectly substitutable, and fitness is derived from the
consumption of these resources. The model contains no spatial parameters, and
is therefore strictly sympatric. We quantify the degree of specialization by
the number of ecotypes formed and the niche breadth of the population, and
observe that these are sensitive to resource influx and trade-offs. Resource
influx has a strong effect on the degree of specialization, with a clear
transition between minimal diversification at high influx and multiple species
evolving at low resource influx. At low resource influx the degree of
specialization further depends on the strength of the trade-offs, with more
ecotypes evolving the stronger trade-offs are. The specialized organisms
persist through negative frequency-dependent selection. In addition, by
analyzing one of the evolutionary radiations in greater detail we demonstrate
that a single mutation alone is not enough to establish a new ecotype, even
though phylogenetic reconstruction identifies that mutation as the branching
point. Instead, it takes a series of additional mutations to ensure the stable
coexistence of the new ecotype in the background of the existing ones,
reminiscent of a recent observa


title: Automatic congruences for diagonals of rational functions

abstract:
  In this paper we use the framework of automatic sequences to study
combinatorial sequences modulo prime powers. Given a sequence whose generating
function is the diagonal of a rational power series, we provide a method, based
on work of Denef and Lipshitz, for computing a finite automaton for the
sequence modulo $p^\alpha$, for all but finitely many primes $p$. This method
gives completely automatic proofs of known results, establishes a number of new
theorems for well-known sequences, and allows us to resolve some conjectures
regarding the Ap\'ery numbers. We also give a second method, which applies to
an algebraic sequence modulo $p^\alpha$ for all primes $p$, but is
significantly slower. Finally, we show that a broad range of multidimensional
sequences possess Lucas products modulo $p$.


title:
Multiple interfaces in diffusional phase transitions in binary
  mesogen-non-mesogen mixtures undergoing metastable phase separations

abstract:
  Theory and simulations of simultaneous chemical demixing and phase ordering
are performed for a mixed order parameter system with an isotropic-isotropic
(I-I) phase separation that is metastable with respect to an isotropic-nematic
(I-N) phase ordering transition. Under certain conditions, the disordered phase
transforms into an ordered phase via the motion of a double front containing a
metastable phase produced by I-I demixing, a thermodynamically driven mechanism
not previously reported. Different kinetic regimes are found depending on the
location of the initial conditions in the thermodynamic phase diagram and the
ratio between diffusional and nematic phase ordering mobilities. For a
diffusional process, depending if the temperature is above or below the
critical co-dissolution point, an inflection point or a phase separation takes
place in the depletion layer. This phase separation leads to the formation of a
second interface where the separation of the two metastable isotropic phases
grows monotonically with time. The observed deviations from the typical Fickian
concentration profiles are associated with strong positive deviations of the
mixture from ideality due to couplings between concentration and nematic
ordering. Although systems of interest include liquid crystalline
nanocomposites, this novel mechanism may apply to any mixture that can undergo
an order-disorder transition and demix.


title:
The Madison plasma dynamo experiment: a facility for studying laboratory
  plasma astrophysics

abstract:
  The Madison plasma dynamo experiment (MPDX) is a novel, versatile, basic
plasma research device designed to investigate flow driven magnetohydrodynamic
(MHD) instabilities and other high-$\beta$ phenomena with astrophysically
relevant parameters. A 3 m diameter vacuum vessel is lined with 36 rings of
alternately oriented 4000 G samarium cobalt magnets which create an
axisymmetric multicusp that contains $\sim$14 m$^{3}$ of nearly magnetic field
free plasma that is well confined and highly ionized $(>50\%)$. At present, 8
lanthanum hexaboride (LaB$_6$) cathodes and 10 molybdenum anodes are inserted
into the vessel and biased up to 500 V, drawing 40 A each cathode, ionizing a
low pressure Ar or He fill gas and heating it. Up to 100 kW of electron
cyclotron heating (ECH) power is planned for additional electron heating. The
LaB$_6$ cathodes are positioned in the magnetized edge to drive toroidal
rotation through ${\bf J}\times{\bf B}$ torques that propagate into the
unmagnetized core plasma. Dynamo studies on MPDX require a high magnetic
Reynolds number $Rm > 1000$, and an adjustable fluid Reynolds number $10< Re
<1000$, in the regime where the kinetic energy of the flow exceeds the magnetic
energy ($M_A^2=($v$/$v$_A)^2 > 1$). Initial results from MPDX are presented
along with a 0-dimensional power and particle balance model to predict the
viscosity and resistivity to achieve dynamo action.


title: Time flat surfaces and the monotonicity of the spacetime Hawking mass

abstract:
  We identify a condition on spacelike 2-surfaces in a spacetime that is
relevant to understanding the concept of mass in general relativity. We prove a
formula for the variation of the spacetime Hawking mass under a uniformly area
expanding flow and show that it is nonnegative for these so-called "time flat
surfaces." Such flows generalize inverse mean curvature flow, which was used by
Huisken and Ilmanen to prove the Riemannian Penrose inequality for one black
hole. A flow of time flat surfaces may have connections to the problem in
general relativity of bounding the mass of a spacetime from below by the
quasi-local mass of a spacelike 2-surface contained therein.


title:
Crouzeix-Raviart MsFEM with Bubble Functions for Diffusion and
  Advection-Diffusion in Perforated Media

abstract:
  The adaptation of Crouzeix - Raviart finite element in the context of
multiscale finite element method (MsFEM) is studied and implemented on
diffusion and advection-diffusion problems in perforated media. It is known
that the approximation of boundary condition on coarse element edges when
computing the multiscale basis functions critically influences the eventual
accuracy of any MsFEM approaches. The weakly enforced continuity of Crouzeix -
Raviart function space across element edges leads to a natural boundary
condition for the multiscale basis functions which relaxes the sensitivity of
our method to complex patterns of perforations. Another ingredient to our
method is the application of bubble functions which is shown to be instrumental
in maintaining high accuracy amid dense perforations. Additionally, the
application of penalization method makes it possible to avoid complex
unstructured domain and allows extensive use of simpler Cartesian meshes.


title: Generic emergence of classical features in quantum Darwinism

abstract:
  Quantum Darwinism explains the emergence of classical reality from the
underlying quantum reality by the fact that a quantum system is observed
indirectly, by looking at parts of its environment, so that only specific
information about the system that is redundantly proliferated to many parts of
the environment becomes accessible and objective. However it is not clear under
what conditions this mechanism holds true. Here we rigorously prove that the
emergence of classicality is a general feature of any quantum dynamics:
observers who acquire information about a quantum system indirectly have access
at most to classical information about one and the same measurement of the
quantum system; moreover, if such information is available to many observers,
they necessarily agree. Remarkably, our analysis goes beyond the
system-environment categorization. We also provide a full characterization of
the so-called quantum discord in terms of local redistribution of correlations.


title:
Some results on the penalised nematic liquid crystals driven by
  multiplicative noise

abstract:
  In this paper we prove several results related to the existence and
uniqueness of solution to coupled highly nonlinear stochastic partial
differential equations (PDEs). These equations are motivated by the dynamics of
nematic liquid crystals under the influence of stochastic external forces.
Firstly, we prove the existence of global weak solution (in sense of both
stochastic analysis and PDEs). We show the pathwise uniqueness of the solution
in 2D domain. Secondly, we establish the existence and uniqueness of local
maximal solution which is strong in sense of both PDEs and stochastic analysis.
In the 2D case, we show that this solution is global. In contrast to several
works in the deterministic setting we replace the Ginzburg-Landau function
${1}_{\lvert \mathbf{n}\rvert \le 1}(\lvert \mathbf{n}\rvert^2-1)\mathbf{n}$ by
a general polynomial $f(\mathbf{n})$ and we give sufficient conditions on the
polynomial $f$ for the aforementioned results to hold. As a by-product of our
investigation we present a general method based on fixed point argument to
establish the existence and uniqueness of a local maximal solution of an
abstract stochastic evolution equations with coefficients satisfying local
Lipschitz condition involving the norms of two different Banach spaces. This
general method can be used to treat several stochastic hydrodynamical models
such as Navier-Stokes, Magnetohydrodynamic (MHD) equations, and the
$\alpha$-models of Navier-Stokes equations and their MHD counterparts.


title:
Snowmass-2013 Cosmic Frontier 3 (CF3) Working Group Summary: Non-WIMP
  dark matter

abstract: Report of the CF-3 Working Group at Community Planning Study "Snowmass-2013".


title: The equivariant cohomology rings of Peterson varieties

abstract:
  The main result of this note is an efficient presentation of the
$S^1$-equivariant cohomology ring of Peterson varieties (in type $A$) as a
quotient of a polynomial ring by an ideal $\mathcal{J}$, in the spirit of the
well-known Borel presentation of the cohomology of the flag variety. Our result
simplifies previous presentations given by Harada-Tymoczko and Bayegan-Harada.
In particular, our result gives an affirmative answer to a conjecture of
Bayegan and Harada that the defining ideal $\mathcal{J}$ is generated by
quadratics.


title: Relative algebraic K-theory by elementary means

abstract:
  In a previous paper I gave a presentation for the Quillen higher algebraic
K-groups of an exact category in terms of "acyclic binary multicomplexes". In
this paper I take that presentation as a definition of the higher K-groups,
generalize it to the relative K-groups of an exact functor between exact
categories, and produce the corresponding long exact sequence by elementary
means, without homotopy theory.


title:
Modeling Complex Liquid Crystals Mixtures: From Polymer Dispersed
  Mesophase to Nematic Nanocolloids

abstract:
  Liquid crystals are synthetic and biological viscoelastic anisotropic soft
matter materials that combine liquid fluidity with crystal anisotropy and find
use in optical devices, sensor/actuators, lubrication, super-fibers. Frequently
mesogens are mixed with colloidal and nanoparticles, other mesogens, isotropic
solvents, thermoplastic polymers, cross-linkable monomers, among others. This
comprehensive review present recent progress on meso and macro scale
thermodynamic modelling, highlighting the (i) novelties in spinodal and binodal
lines in the various phase diagrams, (ii) the growth laws under phase
transitions and phase separation, (iii) the ubiquitous role of metastability
and its manifestation in complex droplet interfaces, (iv) the various spinodal
decompositions due to composition and order fluctuations, (v) the formation of
novel material architectures such as colloidal crystals, (vi) the particle rich
phase behaviour in liquid crystal nanocomposites, (vii) the use of topological
defects to absorb and organize nanoparticles, and (viii) the ability of faceted
nanoparticles to link into strings and organize into lattices. Emphasis is
given to highlight dominant mechanisms and driving forces, and to link them to
specific terms in the free energies of these complex mixtures. The novelties of
incorporating mesophases into blends, solutions, dispersions and mixtures is
revealed by using theory, modelling, computation, and visualization.


title:
CAT(0) cubical complexes for graph products of finitely generated
  abelian groups

abstract:
  We show that every graph product of finitely generated abelian groups acts
properly and cocompactly on a CAT(0) cubical complex. The complex generalizes
(up to subdivision) the Salvetti complex of a right-angled Artin group and the
Coxeter complex of a right-angled Coxeter group. In the right-angled Artin
group case it is related to the embedding into a right-angled Coxeter group
described by Davis and Januszkiewicz. We compare the approaches and also adapt
the argument that the action extends to finite index supergroup that is a graph
product of finite groups.


title:
Dynamics of transient metastable states in mixtures under coupled phase
  ordering and chemical demixing

abstract:
  We present theory and simulation of simultaneous chemical demixing and phase
ordering in a polymer-liquid crystal mixture in conditions where
isotropic-isotropic phase separation is metastable with respect to
isotropic-nematic phase transition. In the case the mechanism is nucleation and
growth, it is found that mesophase growth proceeds by a transient metastable
phase that surround the ordered phase, and whose lifetime is a function of the
ratio of diffusional to orientational mobilities. In the case of spinodal
decomposition, different dynamic regimes are observed depending on the mobility
ratio: metastable phase separation preceding phase ordering, phase ordering
preceding phase separation, or simultaneous phase ordering and phase
separation. Not only the overall dynamics but also the final structure of the
material can be different for each kinetic regime.


title: QCD on the Light-Front -- A Systematic Approach to Hadron Physics

abstract:
  Light-Front Hamiltonian theory provides a rigorous frame-independent
framework for solving nonperturbative QCD. The valence Fock-state wavefunctions
of the light-front QCD Hamiltonian satisfy a single-variable relativistic
equation of motion, analogous to the nonrelativistic radial Schr\"odinger
equation, with an effective confining potential U which systematically
incorporates the effects of higher quark and gluon Fock states. Remarkably, the
potential U has a unique form of a harmonic oscillator potential if one
requires that the chiral QCD action remains conformally invariant. A mass gap
arises when one extends the formalism of de Alfaro, Fubini and Furlan to
light-front Hamiltonian theory. The valence LF meson wavefunctions for zero
quark mass satisfy a single-variable relativistic equation of motion in the
invariant variable $\zeta^2=b^2_\perp x(1-x)$, which is conjugate to the
invariant mass squared. The result is a nonperturbative relativistic
light-front quantum mechanical wave equation which incorporates color
confinement and other essential spectroscopic and dynamical features of hadron
physics, including a massless pion for zero quark mass and linear Regge
trajectories with the same slope in the radial quantum number n and orbital
angular momentum L. The corresponding light-front Dirac equation provides a
model of nucleons. The same light-front equations arise from the holographic
mapping of the soft-wall model modification of AdS_5 space with a unique
dilaton profile to QCD (3+1) at fixed light-front time. Light-front holography
thus provides a precise relation between amplitudes in the fifth dimension of
AdS space and light-front wavefunctions. We also discuss the implications of
the underlying conformal template of QCD for renormalization scale-setting, and
the implications of light-front quantization for the value of the cosmological
constant.


title: Spectral Asymptotics for Operators of Hormander Type

abstract:
  An asymptotic equality of the form $\operatorname{Tr}_{L^2}
e^{-t(L+V)}=Ct^{-\alpha}+o(t^{-\alpha})$ as $t\rightarrow 0$ is given for the
trace of the heat semigroup generated by operators on compact manifolds of the
form $L+V=-\sum_{i=1}^{m}X_i^2 +\sum_{i,j=1}^mc_{ij}[X_i,X_j]+\sum_{i=1}^m
\gamma_iX_i+V$ for smooth real potentials $(V)$ which satisfy H\"{o}rmander's
bracket-generating condition. In the self-adjoint case, a Weyl law is proved
for the spectra of such operators. Analogous results are proved for the
Dirichlet boundary value problem.


title:
160 MeV laser-accelerated protons from CH2 nano-targets for proton
  cancer therapy

abstract:
  Proton (and ion) cancer therapy has proven to be an extremely effective even
supe-rior method of treatment for some tumors 1-4. A major problem, however,
lies in the cost of the particle accelerator facilities; high procurement costs
severely limit the availability of ion radiation therapy, with only ~26 centers
worldwide. Moreover, high operating costs often prevent economic operation
without state subsidies and have led to a shutdown of existing facilities 5,6.
Laser-accelerated proton and ion beams have long been thought of as a way out
of this dilemma, with the potential to provide the required ion beams at lower
cost and smaller facility footprint 7-14. The biggest challenge has been the
achievement of sufficient particle energy for therapy, in the 150-250 MeV range
for protons 15,16. For the last decade, the maximum exper-imentally observed
energy of laser-accelerated protons has remained at ~60 MeV 17. Here we the
experimental demonstration of laser-accelerated protons to energies exceeding
150 MeV, reaching the therapy window. This was achieved through a dif-ferent
acceleration regime rather than a larger laser, specifically a 150 TW laser
with CH2 nano-targets in the relativistically transparent regime 18,19. We also
demonstrate a clear scaling law with laser intensity based on analytical
theory, computer simulations and experimental validation that will enable
design of a pro-totype system spanning the full range of therapeutically
desirable energies.


title:
Measurement of higher-order harmonic azimuthal anisotropy in PbPb
  collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV

abstract:
  Measurements are presented by the CMS Collaboration at the Large Hadron
Collider (LHC) of the higher-order harmonic coefficients that describe the
azimuthal anisotropy of charged particles emitted in sqrt(s[NN]) = 2.76 TeV
PbPb collisions. Expressed in terms of the Fourier components of the azimuthal
distribution, the n = 3-6 harmonic coefficients are presented for charged
particles as a function of their transverse momentum (0.3 < pt < 8.0 GeV),
collision centrality (0-70%), and pseudorapidity (abs(eta) < 2.0). The data are
analyzed using the event plane, multiparticle cumulant, and Lee-Yang zeros
methods, which provide different sensitivities to initial-state fluctuations.
Taken together with earlier LHC measurements of elliptic flow (n = 2), the
results on higher-order harmonic coefficients develop a more complete picture
of the collective motion in high-energy heavy-ion collisions and shed light on
the properties of the produced medium.


title: On the modeling of endocytosis in yeast

abstract:
  The cell membrane deforms during endocytosis to surround extracellular
material and draw it into the cell. Experiments on endocytosis in yeast all
agree that (i) actin polymerizes into a network of filaments exerting active
forces on the membrane to deform it and (ii) the large scale membrane
deformation is tubular in shape. There are three competing proposals, in
contrast, for precisely how the actin filament network organizes itself to
drive the deformation. We use variational approaches and numerical simulations
to address this competition by analyzing a meso-scale model of actin-mediated
endocytosis in yeast. The meso-scale model breaks up the invagination process
into three stages: (i) initiation, where clathrin interacts with the membrane
via adaptor proteins, (ii) elongation, where the membrane is then further
deformed by polymerizing actin filaments, followed by (iii) pinch-off. Our
results suggest that the pinch-off mechanism may be assisted by a pearling-like
instability. We rule out two of the three competing proposals for the
organization of the actin filament network during the elongation stage. These
two proposals could possibly be important in the pinch-off stage, however,
where additional actin polymerization helps break off the vesicle. Implications
and comparisons with earlier modeling of endocytosis in yeast are discussed.


title:
Thermodynamic Modelling of Phase Equilibrium in Nanoparticles-Nematic
  Liquid Crystals Composites

abstract:
  In this work, a theoretical study of phase equilibrium in mixtures of a
calamitic nematic liquid crystal and hard spherical nanoparticles is presented.
A mean-field thermodynamic model is used, where the interactions are considered
to be proportional to the number of contacts, which in turn are proportional to
the areas and area fractions of each component. It is shown that, as the radius
of the particle is increased, the effect of the particles on the
isotropic-nematic transition is less pronounced, and that for large radius the
miscibility increases as the particle radius increases.


title: Why are the effective equations of loop quantum cosmology so accurate?

abstract:
  We point out that the relative Heisenberg uncertainty relations vanish for
non-compact spaces in homogeneous loop quantum cosmology. As a consequence, for
sharply peaked states quantum fluctuations in the scale factor never become
important, even near the bounce point. This shows why quantum back-reaction
effects remain negligible and explains the surprising accuracy of the effective
equations in describing the dynamics of sharply peaked wave packets. This also
underlines the fact that minisuperspace models ---where it is global variables
that are quantized--- do not capture the local quantum fluctuations of the
geometry.


title: Full spectrum of the Rabi model

abstract:
  It is shown that in the Rabi model, for an integer value of the spectral
parameter $x$, in addition to the finite number of the classical Judd states
there exist infinitely many possible eigenstates. These eigenstates exist if
the parameters of the problem are zeros of a certain transcendental function;
in other words, there are infinitely many possible choices of parameters for
which integer $x$ belongs to the spectrum. Morover, it is shown that the
classical Judd eigenstates appear as degenerate cases of the confluent Heun
function.


title:
Magnetic susceptibility and equation of state of N_f = 2+1 QCD with
  physical quark masses

abstract:
  We determine the free energy of strongly interacting matter as a function of
an applied constant and uniform magnetic field. We consider N_f = 2+1 QCD with
physical quark masses, discretized on a lattice by stout improved staggered
fermions and a tree level improved Symanzik pure gauge action, and explore
three different lattice spacings. For magnetic fields of the order of those
produced in non-central heavy ion collisions (eB ~ 0.1 GeV^2) strongly
interacting matter behaves like a medium with a linear response, and is
paramagnetic both above and below the deconfinement transition, with a
susceptibility which steeply rises in the deconfined phase. We compute the
equation of state, showing that the relative increase in the pressure due to
the magnetic field gets larger around the transition, and of the order of 10 %
for eB ~ 0.1 GeV^2.


title: Phase of Quark Condensate and Topological Current in QCD

abstract:
  We propose a new topological charge term in QCD based on flux-tube models. It
couples a superflow of the phase of the quark condensate to the Chern-Simons
current. The usual $\theta$-parameter is replaced by the phase of the quark
condensate, which becomes nontrivial due to the existence of topological
defects such as vortices. This new formulation can address the U(1) problem in
a similar way as in the $\theta$-world and may avoid the strong CP problem as
the new topological charge term is a derivative coupling. Some phenomenological
applications like chiral magnetic effects and possible connections to the
Josephson effect are discussed.


title:
Theoretical study of the ${}^{4}\rm{He}(\gamma,p)^3\rm{H}$ and
  ${}^{4}\rm{He}(\gamma,n)^3\rm{He}$ reactions

abstract:
  {\it Ab initio} calculation of the total cross section for the reactions
$^{4}\rm{He}(\gamma,p)^3\rm{H}$ and $^{4}\rm{He}(\gamma,n)^3\rm{He}$ is
presented, using state-of-the-art nuclear forces. The Lorentz integral
transform (LIT) method is applied, which allows exact treatment of the final
state interaction (FSI). The dynamic equations are solved using the effective
interaction hyperspherical harmonics (EIHH) method. In this calculation of the
cross sections the three-nucleon force is fully taken into account, except in
the source term of the LIT equation for the FSI transition matrix element.


title: Reality, No Matter How You Slice It

abstract:
  In order to reject the notion that information is always about something, the
"It from Bit" idea relies on the nonexistence of a realistic framework that
might underly quantum theory. This essay develops the case that there is a
plausible underlying reality: one actual spacetime-based history, although with
behavior that appears strange when analyzed dynamically (one time-slice at a
time). By using a simple model with no dynamical laws, it becomes evident that
this behavior is actually quite natural when analyzed "all-at-once" (as in
classical statistical mechanics). The "It from Bit" argument against a
spacetime-based reality must then somehow defend the importance of dynamical
laws, even as it denies a reality on which such fundamental laws could operate.


title: Maximal Proper Acceleration and the Quantum-to-Classical Transition

abstract:
  I first review the physical basis for the universal maximal proper
acceleration. Next, I introduce a new formulation for a relativistic scalar
quantum field which generalizes the canonical theory to include the limiting
proper acceleration. This field is then used to construct a simple model of an
uncorrelated many-body system. I next argue that for a macroscopic object
consisting of more than Avogadro's number of atoms, any supposed quantum state
of the object is negligibly small, so that for all practical purposes, the
object is best described by classical mechanics. Thus, a new explanation is
offered for the quantum-to-classical transition and the absence of quantum
superposition of macroscopic objects in the everyday world.


title:
Spectro-Thermometry of M dwarfs and their candidate planets: too hot,
  too cool, or just right?

abstract:
  We use moderate-resolution spectra of nearby late K and M dwarf stars with
parallaxes and interferometrically determined radii to refine their effective
temperatures, luminosities, and metallicities. We use these revised values to
calibrate spectroscopic techniques to infer the fundamental parameters of more
distant late-type dwarf stars. We demonstrate that, after masking out poorly
modeled regions, the newest version of the PHOENIX atmosphere models accurately
reproduce temperatures derived bolometrically. We apply methods to late-type
hosts of transiting planet candidates in the Kepler field, and calculate
effective temperature, radius, mass, and luminosity with typical errors of 57
K, 7%, 11%, and 13%, respectively. We find systematic offsets between our
values and those from previous analyses of the same stars, which we attribute
to differences in atmospheric models utilized for each study. We investigate
which of the planets in this sample are likely to orbit in the circumstellar
habitable zone. We determine that four candidate planets (KOI 854.01, 1298.02,
1686.01, and 2992.01) are inside of or within 1-sigma of a conservative
definition of the habitable zone, but that several planets identified by
previous analyses are not (e.g. KOI 1422.02 and KOI 2626.01). Only one of the
four habitable-zone planets is Earth sized, suggesting a downward revision in
the occurrence of such planets around M dwarfs. These findings highlight the
importance of measuring accurate stellar parameters when deriving parameters of
their orbiting planets.


title: Two distinct spin liquid states in a layered cubic lattice

abstract:
  We construct a family of short-range resonating-valence-bond wave functions
on a layered cubic lattice, allowing for a tunable anisotropy in the amplitudes
assigned to nearest-neighbour valence bonds along one axis. Monte Carlo
simulations reveal that four phases are stabilized over the full range of the
anisotropy parameter. They are separated from one another by a sequence of
continuous quantum phase transitions. An antiferromagnetic phase, centred on
the perfect isotropy point, intervenes between two distinct quantum spin liquid
states. One of them is continuously deformable to the two-dimensional U(1) spin
liquid, which is known to exhibit critical bond correlations. The other has
both spin and bond correlations that decay exponentially. The existence of this
second phase is proof that, contrary to expectations, neither a bipartite
lattice structure nor a conventional Marshall sign rule is an impediment to
realizing a fully gapped quantum spin liquid.


title:
Supersolid states in a hard-core Bose-Hubbard model on a layered
  triangular lattice

abstract:
  We study ground-state properties in a hard-core Bose-Hubbard model on a
layered triangular lattice. Combining cluster mean-field theory with the
density matrix renormalization group method, we discuss the effect of the
interlayer coupling on the supersolid states realized in a single layered
model. By examining the distributions for the particle density and superfluid
order parameter, the rich phase diagram of the system is obtained. We find that
the supersolid states are widely stabilized at a commensurate filling, in
contrast to the case of the single layered model. The nature of the supersolid
states is also addressed.


title: Cosmic Ray Sampling of a Clumpy Interstellar Medium

abstract:
  How cosmic rays sample the multi-phase interstellar medium (ISM) in starburst
galaxies has important implications for many science goals, including
evaluating the cosmic ray calorimeter model for these systems, predicting their
neutrino fluxes, and modeling their winds. Here, we use Monte Carlo simulations
to study cosmic ray sampling of a simple, two-phase ISM under conditions
similar to those of the prototypical starburst galaxy M82. The assumption that
cosmic rays sample the mean density of the ISM in the starburst region is
assessed over a multi-dimensional parameter space where we vary the number of
molecular clouds, the galactic wind speed, the extent to which the magnetic
field is tangled, and the cosmic ray injection mechanism. We evaluate the ratio
of the emissivity from pion production in molecular clouds to the emissivity
that would be observed if the cosmic rays sampled the mean density, and seek
areas of parameter space where this ratio differs significantly from unity. The
assumption that cosmic rays sample the mean density holds over much of
parameter space; however, this assumption begins to break down for high cloud
density, injection close to the clouds, and a very tangled magnetic field. We
conclude by evaluating the extent to which our simulated starburst region
behaves as a proton calorimeter and constructing the time-dependent spectrum of
a burst of cosmic rays.


title:
Conducting fixed points for inhomogeneous quantum wires: a conformally
  invariant boundary theory

abstract:
  Inhomogeneities and junctions in wires are natural sources of scattering, and
hence resistance. A conducting fixed point usually requires an adiabatically
smooth system. One notable exception is "healing", which has been predicted in
systems with special symmetries, where the system is driven to the homogeneous
fixed point. Here we present theoretical results for a different type of
conducting fixed point which occurs in inhomogeneous wires with an abrupt jump
in hopping and interaction strength. We show that it is always possible to tune
the system to an unstable conducting fixed point which does not correspond to
translational invariance. We analyze the temperature scaling of correlation
functions at and near this fixed point and show that two distinct boundary
exponents appear, which correspond to different effective Luttinger liquid
parameters. Even though the system consists of two separate interacting parts,
the fixed point is described by a single conformally invariant boundary theory.
We present details of the general effective bosonic field theory including the
mode expansion and the finite size spectrum. The results are confirmed by
numerical quantum Monte Carlo simulations on spinless fermions. We predict
characteristic experimental signatures of the local density of states near
junctions.


title: The AM CVn binary SDSS J173047.59+554518.5

abstract:
  The AM Canum Venaticorum (AM CVn) binaries are a rare group of
hydrogen-deficient, ultra-short period, mass-transferring white dwarf binaries,
and are possible progenitors of type Ia supernovae. We present time-resolved
spectroscopy of the recently-discovered AM CVn binary SDSS J173047.59+554518.5.
The average spectrum shows strong double-peaked helium emission lines, as well
as a variety of metal lines, including neon; this is the second detection of
neon in an AM CVn binary, after the much brighter system GP Com. We detect no
calcium in the accretion disc, a puzzling feature that has been noted in many
of the longer-period AM CVn binaries. We measure an orbital period, from the
radial velocities of the emission lines, of 35.2 +/- 0.2 minutes, confirming
the ultra-compact binary nature of the system. The emission lines seen in SDSS
J1730 are very narrow, although double-peaked, implying a low inclination,
face-on accretion disc; using the measured velocities of the line peaks, we
estimate i < 11 degrees. This low inclination makes SDSS J1730 an excellent
system for the identification of emission lines.


title: The VLT-Flames Tarantula Survey: an overview of the VFTS results so far

abstract:
  The VLT-FLAMES Tarantula Survey (VFTS) has acquired multi-epoch spectroscopy
of over 800 O, B and Wolf-Rayet stars in the 30 Doradus region with the aim to
investigate a number of important questions related to the evolution of massive
stars and of cluster dynamics. In this paper, I first provide an overview of
the scientific results obtained by the VFTS consortium so far. I then review
the constraints obtained on the multiplicity properties of massive stars in 30
Dor and compare them to our recent results from a Milky Way sample.


title: Cluster categories for marked surfaces: punctured case

abstract:
  We study the cluster categories arising from marked surfaces (with punctures
and non-empty boundaries). By constructing skewed-gentle algebras, we show that
there is a bijection between tagged curves and string objects. Applications
include interpreting dimensions of $\operatorname{Ext}^1$ as intersection
numbers of tagged curves and Auslander-Reiten translation as tagged rotation.
An important consequence is that the cluster(-tilting) exchange graphs of such
cluster categories are connected.


title: On the Minimum Core Mass for Giant Planet Formation at Wide Separations

abstract:
  In the core accretion hypothesis, giant planets form by gas accretion onto
solid protoplanetary cores. The minimum (or critical) core mass to form a gas
giant is typically quoted as 10 Earth masses. The actual value depends on
several factors: the location in the protoplanetary disk, atmospheric opacity,
and the accretion rate of solids. Motivated by ongoing direct imaging searches
for giant planets, this study investigates core mass requirements in the outer
disk. To determine the fastest allowed rates of gas accretion, we consider
solid cores that no longer accrete planetesimals, as this would heat the
gaseous envelope. Our spherical, two-layer atmospheric cooling model includes
an inner convective region and an outer radiative zone that matches onto the
disk. We determine the minimum core mass for a giant planet to form within a
typical disk lifetime of 3 Myr. The minimum core mass declines with disk
radius, from ~8.5 Earth masses at 5 AU to ~3.5 Earth masses at 100 AU, with
standard interstellar grain opacities. Lower temperatures in the outer disk
explain this trend, while variations in disk density are less influential. At
all distances, a lower dust opacity or higher mean molecular weight reduces the
critical core mass. Our non-self-gravitating, analytic cooling model reveals
that self-gravity significantly affects early atmospheric evolution, starting
when the atmosphere is only ~10% as massive as the core.


title: Dark energy from approximate U(1)_{de} symmetry

abstract:
  The PLANCK observation strengthens the argument that the observed
acceleration of the Universe is dominated by the invisible component of dark
energy. We address how this extremely small DE density can be obtained in an
ultraviolet completed theory. From two mass scales, the grand unification scale
M_G and the Higgs boson mass, we parametrize this dark energy(DE). To naturally
generate an extremely small DE term, we introduce an almost flat DE potential
of a pseudo-Goldstone boson of an approximate global symmetry U(1)_{de} from
some discrete symmetries allowed in an ultraviolet completed theory. For the DE
potential to be extremely shallow, the pseudo-Goldstone boson is required not
to couple to the QCD anomaly. This fixes uniquely the nonrenormalizable term
generating the potential suppressed by M_G^7 in supergravity models.


title:
The Population of Giant Clumps in Simulated High-z Galaxies: In-situ and
  Ex-situ, Migration and Survival

abstract:
  We study the properties of giant clumps and their radial gradients in
high-$z$ disc galaxies using AMR cosmological simulations. Our sample consists
of 770 snapshots in the redshift range $z=4-1$ from 29 galaxies that at $z=2$
span the stellar mass range $(0.2-3)\times 10^{11}M_{\odot}$. Extended gas
discs exist in 83% of the snapshots. Clumps are identified by gas density in 3D
and their stellar and dark matter components are considered thereafter. While
most of the overdensities are diffuse and elongated, 91% of their mass and 83%
of their star-fromation rate (SFR) are in compact round clumps. Nearly all
galaxies have a central, massive bulge clump, while 70% of the discs show
off-center clumps, 3-4 per galaxy. The fraction of clumpy discs peaks at
intermediate disc masses. Clumps are divided based on dark-matter content into
$\textit{in-situ}$ and $\textit{ex-situ}$, originating from violent disc
instability (VDI) and minor mergers respectively. 60% of the discs are in a VDI
phase showing off-center $\textit{in-situ}$ clumps, which contribute 1-7% of
the disc mass and 5-45% of its SFR. The $\textit{in-situ}$ clumps constitute
75% of the off-center clumps in terms of number and SFR but only half the mass,
each clump containing on average 1% of the disc mass and 6% of its SFR. They
have young stellar ages, $100-400 {\rm Myr}$, and high specific SFR (sSFR),
$1-10 {\rm Gyr}^{-1}$. They exhibit gradients resulting from inward clump
migration, where the inner clumps are somewhat more massive and older, with
lower gas fraction and sSFR and higher metallicity. Similar observed gradients
indicate that clumps survive outflows. The \exsitu clumps have stellar ages
$0.5-3 {\rm Gyr}$ and sSFR $\sim 0.1-2 {\rm Gyr}^{-1}$, and they exhibit weaker
gradients. Massive clumps of old stars at large radii are likely \exsitu
mergers, though half of them share the disc rotation.


title:
Probing the Dark Ages at Z~20: The SCI-HI 21 cm All-Sky Spectrum
  Experiment

abstract:
  We present first results from the SCI-HI experiment, which we used to measure
the all-sky-averaged \cm brightness temperature in the redshift range
14.8<z<22.7. The instrument consists of a single broadband sub-wavelength size
antenna and a sampling system for real-time data processing and recording.
Preliminary observations were completed in June 2013 at Isla Guadalupe, a
Mexican biosphere reserve located in the Pacific Ocean. The data was cleaned to
excise channels contaminated by radio frequency interference (RFI), and the
system response was calibrated by comparing the measured brightness temperature
to the Global Sky Model of the Galaxy and by independent measurement of Johnson
noise from a calibration terminator. We present our results, discuss the
cosmological implications, and describe plans for future work.


title: Holographic entanglement and causal information in coherent states

abstract:
  Scalar solitons in global AdS4 are holographically dual to coherent states
carrying a non-trivial condensate of a scalar operator. We study the
holographic information content of these states, focusing on a particular
spatial region, by examining the entanglement entropy and causal holographic
information. We show generically that whenever the dimension of the condensed
operator is sufficiently low (characterized by the double-trace operator
becoming relevant), such coherent states have lower entanglement and causal
holographic information than the vacuum state of the system, despite having
greater energy. We also use these geometries to illustrate the fact that causal
wedges associated with a simply-connected boundary region can have non-trivial
topology even in causally trivial spacetimes.


title:
Environmental dynamics, correlations, and the emergence of noncanonical
  equilibrium states in open quantum systems

abstract:
  Quantum systems are invariably open, evolving under surrounding influences
rather than in isolation. Standard open quantum system methods eliminate all
information on the environmental state to yield a tractable description of the
system dynamics. By incorporating a collective coordinate of the environment
into the system Hamiltonian, we circumvent this limitation. Our theory provides
straightforward access to important environmental properties that would
otherwise be obscured, allowing us to quantify the evolving system-environment
correlations. As a direct result, we show that the generation of robust
system-environment correlations that persist into equilibrium (heralded also by
the emergence of non-Gaussian environmental states) renders the canonical
system steady-state almost always incorrect. The resulting equilibrium states
deviate markedly from those predicted by standard perturbative techniques and
are instead fully characterised by thermal states of the mapped
system-collective coordinate Hamiltonian. We outline how noncanonical system
states could be investigated experimentally to study deviations from canonical
thermodynamics, with direct relevance to molecular and solid-state nanosystems.


title:
Quantum mechanical which-way experiment with an internal degree of
  freedom

abstract:
  For a particle travelling through an interferometer, the trade-off between
the available which-way information and the interference visibility provides a
lucid manifestation of the quantum mechanical wave-particle duality. Here we
analyze this relation for a particle possessing an internal degree of freedom
such as spin. We quantify the trade-off with a general inequality that paints
an unexpectedly intricate picture of wave-particle duality when internal states
are involved. Strikingly, in some instances which-way information becomes
erased by introducing classical uncertainty in the internal degree of freedom.
Furthermore, even imperfect interference visibility measured for a suitable set
of spin preparations can be sufficient to infer absence of which-way
information. General results are illustrated with a proof-of-principle single
photon experiment.


title:
Master equation for dissipative interacting qubits in a common
  environment

abstract:
  In this paper, we derive a microscopic master equation for a pair of
XY-coupled two-level systems interacting with the same memoryless reservoir. In
particular, we apply this master equation to the case of a pair of two-level
atoms in free space where we can clearly contrast the predictions made with the
microscopic master equation obtained here and the phenomenological approaches
where the atom-atom coupling is included just \textit{a posteriori}, i.e, not
taking into account in the derivation of the open system equation of motion. We
show, for instance, that the phenomenological approach fails completely in the
assessment of the role played by the symmetric and antisymmetric decay
channels. As a consequence, the predictions related to collective effects such
as superradiance, for instance, are misleading in the phenomenological
approach. We also obtain the fluorescence spectrum using the microscopic model
developed here.


title:
Thermalization, Error-Correction, and Memory Lifetime for Ising Anyon
  Systems

abstract:
  We consider two-dimensional lattice models that support Ising anyonic
excitations and are coupled to a thermal bath. We propose a phenomenological
model for the resulting short-time dynamics that includes pair-creation,
hopping, braiding, and fusion of anyons. By explicitly constructing topological
quantum error-correcting codes for this class of system, we use our
thermalization model to estimate the lifetime of the quantum information stored
in the encoded spaces. To decode and correct errors in these codes, we adapt
several existing topological decoders to the non-Abelian setting. We perform
large-scale numerical simulations of these two-dimensional Ising anyon systems
and find that the thresholds of these models range between 13% to 25%. To our
knowledge, these are the first numerical threshold estimates for quantum codes
without explicit additive structure.


title: A classical WR model with $q$ particle types

abstract:
  A version of the Widom--Rowlinson model is considered, where particles of $q$
types coexist, with a given collection of hard-core exclusion diameters. For
$q\leq 4$, in the case of large equal fugacities, we give a complete
description of the pure phase picture, based on the theory of dominant ground
states.


title:
Intermittency for the wave and heat equations with fractional noise in
  time

abstract:
  In this article, we consider the stochastic wave and heat equations driven by
a Gaussian noise which is spatially homogeneous and behaves in time like a
fractional Brownian motion with Hurst index $H>1/2$. The solutions of these
equations are interpreted in the Skorohod sense. Using Malliavin calculus
techniques, we obtain an upper bound for the moments of order $p\geq2$ of the
solution. In the case of the wave equation, we derive a Feynman-Kac-type
formula for the second moment of the solution, based on the points of a planar
Poisson process. This is an extension of the formula given by Dalang, Mueller
and Tribe [Trans. Amer. Math. Soc. 360 (2008) 4681-4703], in the case $H=1/2$,
and allows us to obtain a lower bound for the second moment of the solution.
These results suggest that the moments of the solution grow much faster in the
case of the fractional noise in time than in the case of the white noise in
time.


title: Isospin-violating dark matter from a double portal

abstract:
  We study a simple model that can give rise to isospin-violating interactions
of Dirac fermion asymmetric dark matter to protons and neutrons through the
interference of a scalar and U(1)$'$ gauge boson contribution. The model can
yield a large suppression of the elastic scattering cross section off Xenon
relative to Silicon thus reconciling CDMS-Si and LUX results while being
compatible with LHC findings on the 126 GeV Higgs, electroweak precision tests
and flavour constraints.


title: A note on intermittency for the fractional heat equation

abstract:
  The goal of the present note is to study intermittency properties for the
solution to the fractional heat equation $$\frac{\partial u}{\partial t}(t,x) =
-(-\Delta)^{\beta/2} u(t,x) + u(t,x)\dot{W}(t,x), \quad t>0,x \in \bR^d$$ with
initial condition bounded above and below, where $\beta \in (0,2]$ and the
noise $W$ behaves in time like a fractional Brownian motion of index $H>1/2$,
and has a spatial covariance given by the Riesz kernel of index $\alpha \in
(0,d)$. As a by-product, we obtain that the necessary and sufficient condition
for the existence of the solution is $\alpha<\beta$.


title: The Role of Carbon in Extrasolar Planetary Geodynamics and Habitability

abstract:
  The proportions of oxygen, carbon and major rock-forming elements (e.g. Mg,
Fe, Si) determine a planet's dominant mineralogy. Variation in a planet's
mineralogy subsequently affects planetary mantle dynamics as well as any deep
water or carbon cycle. Through thermodynamic models and high pressure diamond
anvil cell experiments, we demonstrate the oxidation potential of C is above
that of Fe at all pressures and temperatures indicative of 0.1 - 2 Earth-mass
planets. This means that for a planet with (Mg+2Si+Fe+2C)/O > 1, excess C in
the mantle will be in the form of diamond. We model the general dynamic state
of planets as a function of interior temperature, carbon composition, and size,
showing that above a critical threshold of $\sim$3 atom% C, limited to no
mantle convection will be present assuming an Earth-like geotherm. We assert
then that in the C-(Mg+2Si+Fe)-O system, only a very small compositional range
produce habitable planets. Planets outside of this habitable range will be
dynamically sluggish or stagnant, thus having limited carbon or water cycles
leading to surface conditions inhospitable to life as we know it.


title: The Ext algebra of the principal block of the Mathieu group M_11

abstract:
  We complete the calculation of the Ext algebra of the principal 2-block of
the Mathieu group M_11, extending work of Benson-Carlson and of Pawloski - and
duplicating work of Generalov.


title:
Hydrogen-Poor Superluminous Supernovae and Long-Duration Gamma-Ray
  Bursts Have Similar Host Galaxies

abstract:
  We present optical spectroscopy and optical/near-IR photometry of 31 host
galaxies of hydrogen-poor superluminous supernovae (SLSNe), including 15 events
from the Pan-STARRS1 Medium Deep Survey. Our sample spans the redshift range
0.1 < z < 1.6 and is the first comprehensive host galaxy study of this specific
subclass of cosmic explosions. Combining the multi-band photometry and
emission-line measurements, we determine the luminosities, stellar masses, star
formation rates and metallicities. We find that as a whole, the hosts of SLSNe
are a low-luminosity (<M_B> ~ -17.3 mag), low stellar mass (<M_*> ~ 2 x 10^8
M_sun) population, with a high median specific star formation rate (<sSFR> ~ 2
Gyr^-1). The median metallicity of our spectroscopic sample is low, 12 +
log(O/H}) ~ 8.35 ~ 0.45 Z_sun, although at least one host galaxy has solar
metallicity. The host galaxies of H-poor SLSNe are statistically distinct from
the hosts of GOODS core-collapse SNe (which cover a similar redshift range),
but resemble the host galaxies of long-duration gamma-ray bursts (LGRBs) in
terms of stellar mass, SFR, sSFR and metallicity. This result indicates that
the environmental causes leading to massive stars forming either SLSNe or LGRBs
are similar, and in particular that SLSNe are more effectively formed in low
metallicity environments. We speculate that the key ingredient is large core
angular momentum, leading to a rapidly-spinning magnetar in SLSNe and an
accreting black hole in LGRBs.


title:
Single crystal growth and characterization of the large-unit-cell
  compound Cu13Ba

abstract:
  Single crystals of Cu$_{13}$Ba were successfully grown out of Ba-Cu self
flux. Temperature dependent magnetization, $M(T)$, electrical resistivity,
$\rho(T)$, and specific heat, $C_p(T)$, data are reported. Isothermal
magnetization measurements, $M(H)$, show clear de Haas-van Alphen oscillations
at $T$ = 2 K for applied fields as low as $\mu_0H$ = 1T. An anomalous behavior
of the magnetic susceptibility is observed up to $T$ ~ 50K reflecting the
effect of de Haas-van Alphen oscillations at fairly high temperatures. The
field- and temperature-dependencies of the magnetization indicate the presence
of diluted magnetic impurities with a concentration of the order of 0.01at.%.
Accordingly, the minimum and lower temperature rise observed in the electrical
resistivity at and below $T$ = 15K is attributed to the Kondo impurity effect.