title: DIGIT survey of far-infrared lines from protoplanetary disks I

abstract:
  [abridged] We present far-infrared spectroscopic observations of PMS stars
taken with Herschel/PACS as part of the DIGIT key project. The sample includes
22 Herbig AeBe and 8 T Tauri sources. Multiple atomic fine structure and
molecular lines are detected at the source position: [OI], [CII], CO, OH, H_2O,
CH^+. The most common feature is the [OI] 63micron line detected in almost all
of the sources followed by OH. In contrast with CO, OH is detected toward both
Herbig AeBe groups (flared and non-flared sources). An isothermal LTE slab
model fit to the OH lines indicates column densities of 10^13 < N_OH < 10^16
cm^-2, emitting radii 15 < r < 100 AU and excitation temperatures 100 < T_ex <
400 K. The OH emission thus comes from a warm layer in the disk at intermediate
stellar distances. Warm H_2O emission is detected through multiple lines toward
the T Tauri systems AS 205, DG Tau, S CrA and RNO 90 and three Herbig AeBe
systems HD 104237, HD 142527, HD 163296 (through line stacking). Overall,
Herbig AeBe sources have higher OH/H_2O abundance ratios across the disk than
do T Tauri disks, from near- to far-infrared wavelengths. Far-infrared CH^+
emission is detected toward HD 100546 and HD 97048. The slab model suggests
moderate excitation (T_ex ~ 100 K) and compact (r ~ 60 AU) emission in the case
of HD 100546. The [CII] emission is spatially extended in all sources where the
line is detected. This suggests that not all [CII] emission is associated with
the disk and that there is a substantial contribution from diffuse material
around the young stars. The flux ratios of the atomic fine structure lines are
consistent with a disk origin for the oxygen lines for most of the sources.


title: Local profile of fully bubbling solutions to SU(n+1) Toda Systems

abstract:
  In this article we prove that for locally defined singular SU(n+1) Toda
systems in R^2, the profile of fully bubbling solutions near the singular
source can be accurately approximated by global solutions. The main ingredients
of our new approach are the classification theorem of Lin-Wei-Ye and the
non-degeneracy of the linearized Toda system, which make us overcome the
difficulties that come from the lack of symmetry and the singular source.


title:
Derivation of Generalized Thomas-Bargmann-Michel-Telegdi Equation for a
  Particle with Electric Dipole Moment

abstract:
  General classical equation of spin motion is explicitly derived for a
particle with magnetic and electric dipole moments in electromagnetic fields.
Equation describing the spin motion relatively the momentum direction in
storage rings is also obtained.


title: Neutrino mass textures from F-theory

abstract:
  Experimental data on the neutrino mixing and masses strongly suggest an
underlying approximate symmetry of the relevant Yukawa superpotential terms.
Intensive phenomenological explorations during the last decade indicate that
permutation symmetries such as S_4, A_4 and their subgroups, under certain
assumptions and vacuum alignments, predict neutrino mass textures compatible
with such data. Motivated by these findings, in the present work we analyse the
neutrino properties in F-theory GUT models derived in the framework of the
maximal underlying E_8 symmetry in the elliptic fibration. More specifically,
we consider local F-SU(5) GUT models and study in detail spectral cover
geometries with monodromies associated to the finite symmetries S_4, A_4 and
their transitive subgroups, including the dihedral group D_4 and Z_2 X Z_2. We
discuss various issues that emerge in the implementation of S_4, A_4 neutrino
models in the F-theory context and suggest how these can be resolved. Realistic
models are presented for the case of monodromies based on their transitive
subgroups. We exemplify this procedure with a detailed analysis performed for
the case of Z_2 X Z_2 model.


title: Casimir energy in the Gribov-Zwanziger approach to QCD

abstract:
  In this paper we study the Casimir energy of QCD within the Gribov-Zwanziger
approach. In this model non-perturbative effects of gauge copies are properly
taken into account. We show that the computation of the Casimir energy for the
MIT bag model within the (refined) Gribov-Zwanziger approach not only gives the
correct sign but it also gives an estimate for the radius of the bag.


title:
Experimental Observation of a Fundamental Length Scale of Waves in
  Random Media

abstract:
  Waves propagating through a weakly scattering random medium show a pronounced
branching of the flow accompanied by the formation of freak waves, i.e.,
extremely intense waves. Theory predicts that this strong fluctuation regime is
accompanied by its own fundamental length scale of transport in random media,
parametrically different from the mean free path or the localization length. We
show numerically how the scintillation index can be used to assess the scaling
behavior of the branching length. We report the experimental observation of
this scaling using microwave transport experiments in quasi-two-dimensional
resonators with randomly distributed weak scatterers. Remarkably, the scaling
range extends much further than expected from random caustics statistics.


title: Integrable Deformations of the XXZ Spin Chain

abstract:
  We consider integrable deformations of the XXZ spin chain for periodic and
open boundary conditions. In particular, we classify all long-range
deformations and study their impact on the spectrum. As compared to the XXX
case, we have the z-spin at our disposal, which induces two additional
deformations: the short-range magnetic twist and a new long-range
momentum-dependent twist.

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


title:
Starspots - Transit Depth Relation of the Evaporating Planet Candidate
  KIC 12557548b

abstract:
  Violent variation of transit depths and an ingress-egress asymmetry of the
transit light curve discovered in KIC 12557548 have been interpreted as
evidences of a catastrophic evaporation of atmosphere with dust (M_p gtrsim 1
M_oplus/Gyr) from a close-in small planet. To explore what drives the anomalous
atmospheric escape, we perform time-series analysis of the transit depth
variation of Kepler archival data for ~ 3.5 yr. We find a ~ 30% periodic
variation of the transit depth with P1 = 22.83 pm 0.21 days, which is within
the error of the rotation period of the host star estimated using the light
curve modulation, Prot = 22.91 pm 0.24 days. We interpret the results as
evidence that the atmospheric escape of KIC 12557548b correlates with stellar
activity. We consider possible scenarios that account for both the mass loss
rate and the correlation with stellar activity. X-ray and ultraviolet
(XUV)-driven evaporation is possible if one accepts a relatively high XUV flux
and a high efficiency for converting the input energy to the kinetic energy of
the atmosphere. Star-planet magnetic interaction is another possible scenario
though huge uncertainty remains for the mass loss rate.


title:
Search for top-squark pair production in the single-lepton final state
  in pp collisions at sqrt(s) = 8 TeV

abstract:
  This paper presents a search for the pair production of top squarks in events
with a single isolated electron or muon, jets, large missing transverse
momentum, and large transverse mass. The data sample corresponds to an
integrated luminosity of 19.5 inverse femtobarns of pp collisions collected in
2012 by the CMS experiment at the LHC at a center-of-mass energy of sqrt(s) = 8
TeV. No significant excess in data is observed above the expectation from
standard model processes. The results are interpreted in the context of
supersymmetric models with pair production of top squarks that decay either to
a top quark and a neutralino or to a bottom quark and a chargino. For small
mass values of the lightest supersymmetric particle, top-squark mass values up
to around 650 GeV are excluded.


title:
A facile process for soak-and-peel delamination of CVD graphene from
  substrates using water

abstract:
  We demonstrate a simple technique to transfer CVD-grown graphene from copper
and platinum substrates using a soak-and-peel delamination technique utilizing
only hot deionized water. The lack of chemical etchants results in cleaner CVD
graphene films minimizing unintentional doping, as confirmed by Raman and
electrical measurements. The process allows the reuse of substrates and hence
can enable the use of oriented substrates for growth of higher quality
graphene, and is an inherently inexpensive and scalable process for large-area
production.


title:
Almost sure existence of Navier-Stokes Equations with randomized data in
  the whole space

abstract:
  This paper considers the supercritical Navier-Stokes equations posed in the
whole space $\R^d$, with suitably randomized initial data, in the weak solution
setting. The global weak solutions are constructed for a large set of initial
data in $H^{-s}(\R^d)$ for some $s>0$ via a probabilistic argument, and this in
turn implies the almost sure existence.


title: Bias Free Gap Creation in Bilayer Graphene

abstract:
  For graphene to be utilized in the digital electronics industry the challenge
is to create bandgaps of order 1eV as simply as possible. The most successful
methods for the creation of gaps in graphene are (a) confining the electrons in
nanoribbons, which is technically difficult or (b) placing a potential
difference across bilayer graphene, which is limited to gaps of around 300meV
for reasonably sized electric fields. Here we propose that electronic band gaps
can be created without applying an external electric field, by using the
electron-phonon interaction formed when bilayer graphene is sandwiched between
highly polarisable ionic materials. We derive and solve self-consistent
equations, finding that a large gap can be formed for intermediate
electron-phonon coupling. The gap originates from the amplification of an
intrinsic Coulomb interaction due to the proximity of carbon atoms in
neighbouring planes.


title: Sparse Representations for Packetized Predictive Networked Control

abstract:
  We investigate a networked control architecture for LTI plant models with a
scalar input. Communication from controller to actuator is over an unreliable
network which introduces packet dropouts. To achieve robustness against
dropouts, we adopt a packetized predictive control paradigm wherein each
control packet transmitted contains tentative future plant input values. The
novelty of our approach is that we seek that the control packets transmitted be
sparse. For that purpose, we adapt tools from the area of compressed sensing
and propose to design the control packets via on-line minimization of a
suitable L1/L2 cost function. We then show how to choose parameters of the cost
function to ensure that the resultant closed loop system be practically stable,
provided the maximum number of consecutive packet dropouts is bounded. A
numerical example illustrates that sparsity reduces bit-rates, thereby making
our proposal suited to control over unreliable and bit-rate limited networks.


title: A Heliopause Spectrum for Electrons

abstract:
  We present a heliopause spectrum for galactic electrons over an energy range
from 1 MeV to 50 GeV at 122 AU from the Sun. This spectrum can be considered
the lowest possible local interstellar spectrum (LIS). This is obtained by
using a comprehensive numerical model for solar modulation in comparison with
Voyager 1 observations during 2010 and PAMELA data at Earth. Below about 1 GeV,
this LIS exhibits a power law with E^(-(1.5 plus minus 0.1), where E is the
kinetic energy of these electrons. Reproducing the PAMELA electron spectrum for
2009 requires a LIS with a different power law above about 5 GeV of the form
E^(-3.15 plus minus 0.05). The heliopause spectrum thus consists of two power
laws with a break between about 800 MeV and about 2 GeV.


title:
Hydrodynamic theory of Rotating Ultracold Bose Einstein Condensates in
  Supersolid Phase

abstract:
  Within mean field Gross-Pitaevskii framework, ultra cold atomic condensates
with long range interaction is predicted to have a supersolid like ground state
beyond a critical interaction strength. Such mean field supersolid like ground
state has periodically modulated superfluid density which implies the
coexistence of superfluid and crystalline order. Ultra cold atomic system in
such mean field ground state can be subjected to artificial gauge field created
either through rotation or by introducing space dependent coupling among
hyperfine states of the atoms using Raman lasers. Starting from this
Gross-Pitaevskii energy functional that describes such systems at zero
temperature, we construct hydrodynamic theory to describe the low energy long
wavelength excitations of such rotating supersolid of weakly interacting ultra
cold atoms in two spatial dimensions for generic type of long range
interaction. We treat the supersolidity in such system within the framework of
well known two fluid approximation. Considering such system in the fast
rotation limit where a vortex lattice in superfluid coexists with the
supersolid lattice, we analytically obtain the dispersion relations of
collective excitations around this equilibrium state. The dispersion relation
gives the modes of the rotating supersolid which can be experimentally measured
within the current technology. We point out that this can clearly identify such
a ultra cold atomic supersolid phase in an unambiguous way.


title:
Coupling of optical far-fields into aperture-less plasmonic nanofibre
  tips

abstract:
  This paper reports on the excitation of surface plasmons on gold-coated
nanofibre tips by side-illumination with a laser beam and the coupling of the
surface plasmons to the optical fiber. The measurements show a strong
dependence of the coupling efficiency on the incidence angle with a maximum
coupling efficiency on the order of few percent. Moreover, the fibre tip was
used as scanning probe device for measuring the beam waist of a focussed laser
beam. This work is motivated by the goal to use such plasmonic nanofibre tips
in quantum optics experiments with cold atoms.


title: A prime decomposition theorem for the 2-string link monoid

abstract:
  In this paper we use 3-manifold techniques to illuminate the structure of the
string link monoid. In particular, we give a prime decomposition theorem for
string links on two components as well as give necessary conditions for string
links to commute under the stacking operation.


title: Generalized effective hamiltonian for graphene under non-uniform strain

abstract:
  We use a symmetry approach to construct a systematic derivative expansion of
the low energy effective Hamiltonian modifying the continuum Dirac description
of graphene in the presence of non-uniform elastic deformations. We extract all
experimentally relevant terms and describe their physical significance. Among
them there is a new gap-opening term that describes the Zeeman coupling of the
elastic pseudomagnetic field and the pseudospin. We determine the value of the
couplings using a generalized tight binding model.


title: Improving the accuracy of the AVF method

abstract:
  The Average Vector Field (AVF) method is a B-series scheme of the second
order. As a discrete gradient method it preserves exactly the energy integral
for any canonical Hamiltonian system. We present and discuss two locally exact
and energy-preserving modifications of the AVF method: AVF-LEX (of the third
order) and AVF-SLEX (of the fourth order). Applications to spherically
symmetric potentials are given, including a compact explicit expression for the
AVF scheme for the Coulomb-Kepler problem.


title:
Magnetocrystalline anisotropy energy for adatoms and monolayers on
  non-magnetic substrates: where does it comes from?

abstract:
  The substrate contribution to the magnetic anisotropy energy (MAE) of
supported nanostructures can be quantified by a site-selective manipulation of
the spin-orbit coupling (SOC) and the effective exchange field B_ex. A
systematic study of Co adatoms and Co monolayers on the (111) surfaces of Cu,
Ag, Au, Pd and Pt is performed to study common trends in this class of
materials. It is found that for adatoms, the substrate contribution is
relatively small (10-30% of the MAE) while for monolayers, the substrate
contribution can be substantial. The contribution from the SOC is much more
important than the contribution from the exchange field B_ex, except for highly
polarizable substrates with a strong SOC (such as Pt). The substrate always
promotes the tendency to an out-of-plane orientation of the easy magnetic axis
for all the investigated systems.


title:
Low regularity local well-posedness for the Maxwell-Klein-Gordon
  equations in Lorenz gauge

abstract:
  The Cauchy problem for the Maxwell-Klein-Gordon equations in Lorenz gauge in
two and three space dimensions is locally well-posed for low regularity data
without finite energy. The result relies on the null structure for the main
bilinear terms which was shown to be not only present in Coulomb gauge but also
in Lorenz gauge by Selberg and Tesfahun, who proved global well-posedness for
finite energy data in three space dimensions. This null structure is combined
with product estimates for wave-Sobolev spaces given systematically by
d'Ancona, Foschi and Selberg.


title:
Measurement of the atmospheric $\nu_\mu$ energy spectrum from 100 GeV to
  200 TeV with the ANTARES telescope

abstract:
  Atmospheric neutrinos are produced during cascades initiated by the
interaction of primary cosmic rays with air nuclei. In this paper, a
measurement of the atmospheric \nu_\mu + \bar{\nu}_\mu energy spectrum in the
energy range 0.1 - 200 TeV is presented, using data collected by the ANTARES
underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is
~25% higher than predicted by the conventional neutrino flux, and compatible
with the measurements reported in ice. The flux is compatible with a single
power-law dependence with spectral index \gamma_{meas}=3.58\pm 0.12. With the
present statistics the contribution of prompt neutrinos cannot be established.


title: Universal codes of the natural numbers

abstract:
  A code of the natural numbers is a uniquely-decodable binary code of the
natural numbers with non-decreasing codeword lengths, which satisfies Kraft's
inequality tightly. We define a natural partial order on the set of codes, and
show how to construct effectively a code better than a given sequence of codes,
in a certain precise sense. As an application, we prove that the existence of a
scale of codes (a well-ordered set of codes which contains a code better than
any given code) is independent of ZFC.


title:
Intrinsic electron-glass effects in strongly-localized thallium-oxide
  films

abstract:
  Transport measurements made on films of thallium-oxide (n-type semiconductor)
are presented and discussed. The focus in this work is on the
strongly-localized regime where charge transport is by variable-range-hopping.
It is demonstrated that, at liquid-helium temperatures, these films exhibit all
the characteristic features of intrinsic electron-glasses. These include a slow
(logarithmic in time) conductance-relaxation that may be induced by any of the
following protocols: Quench-cooling from high temperatures, sudden change of
gate-voltage, exposure to infrared radiation, and stressing the system with a
non-Ohmic field. The microstructure of the films are characterized by electron
microscopy and their carrier-concentration are measured by Hall effect.
Field-effect experiments reveal a memory-dip that has a width compatible with
the carrier-concentration of the system as compared with previously studied
electron-glasses. It is observed that the common ingredient in all the systems
that exhibit electron-glass effects is high carrier-concentration suggesting
that their localized sites may be multi-occupied even when deep into the
insulating regime. That lightly-doped semiconductors do not show intrinsic
electron-glass effects is consistent with this empirical observation. The
connection between the memory-dip and the Coulomb-gap is discussed in light of
these findings.


title:
Optimizing for confidence - Costs and opportunities at the frontier
  between abstraction and reality

abstract:
  Is there a relationship between computing costs and the confidence people
place in the behavior of computing systems? What are the tuning knobs one can
use to optimize systems for human confidence instead of correctness in purely
abstract models? This report explores these questions by reviewing the
mechanisms by which people build confidence in the match between the physical
world behavior of machines and their abstract intuition of this behavior
according to models or programming language semantics. We highlight in
particular that a bottom-up approach relies on arbitrary trust in the accuracy
of I/O devices, and that there exists clear cost trade-offs in the use of I/O
devices in computing systems. We also show various methods which alleviate the
need to trust I/O devices arbitrarily and instead build confidence
incrementally "from the outside" by considering systems as black box entities.
We highlight cases where these approaches can reach a given confidence level at
a lower cost than bottom-up approaches.


title:
A Note on Topology Preservation in Classification, and the Construction
  of a Universal Neuron Grid

abstract:
  It will be shown that according to theorems of K. Menger, every neuron grid
if identified with a curve is able to preserve the adopted qualitative
structure of a data space. Furthermore, if this identification is made, the
neuron grid structure can always be mapped to a subset of a universal neuron
grid which is constructable in three space dimensions. Conclusions will be
drawn for established neuron grid types as well as neural fields.


title:
Exchange fluctuation theorem for heat transport between multi-terminal
  harmonic systems

abstract:
  We study full counting statistics for transferred heat and entropy production
between multi-terminal systems in absence of a finite junction. The systems are
modelled as collections of coupled harmonic oscillators which are kept at
different equilibrium temperatures and are connected via arbitrary time
dependent couplings. Following consistent quantum framework and two-time
measurement concept we obtain analytical expressions for the generalized
cumulant generating function. We discuss transient and steady-state fluctuation
theorems for the transferred quantities. We also address the effect of coupling
strength on the exchange fluctuation theorem.


title:
The stability of a graph partition: A dynamics-based framework for
  community detection

abstract:
  Recent years have seen a surge of interest in the analysis of complex
networks, facilitated by the availability of relational data and the
increasingly powerful computational resources that can be employed for their
analysis. Naturally, the study of real-world systems leads to highly complex
networks and a current challenge is to extract intelligible, simplified
descriptions from the network in terms of relevant subgraphs, which can provide
insight into the structure and function of the overall system.
  Sparked by seminal work by Newman and Girvan, an interesting line of research
has been devoted to investigating modular community structure in networks,
revitalising the classic problem of graph partitioning.
  However, modular or community structure in networks has notoriously evaded
rigorous definition. The most accepted notion of community is perhaps that of a
group of elements which exhibit a stronger level of interaction within
themselves than with the elements outside the community. This concept has
resulted in a plethora of computational methods and heuristics for community
detection. Nevertheless a firm theoretical understanding of most of these
methods, in terms of how they operate and what they are supposed to detect, is
still lacking to date.
  Here, we will develop a dynamical perspective towards community detection
enabling us to define a measure named the stability of a graph partition. It
will be shown that a number of previously ad-hoc defined heuristics for
community detection can be seen as particular cases of our method providing us
with a dynamic reinterpretation of those measures. Our dynamics-based approach
thus serves as a unifying framework to gain a deeper understanding of different
aspects and problems associated with community detection and allows us to
propose new dynamically-inspired criteria for community structure.

categories: physics.soc-ph cond-mat.stat-mech cs.SI physics.data-an


title: Investigation of indoor localization with ambient FM radio stations

abstract:
  Localization plays an essential role in many ubiquitous computing
applications. While the outdoor location-aware services based on GPS are
becoming increasingly popular, their proliferation to indoor environments is
limited due to the lack of widely available indoor localization systems. The
de-facto standard for indoor positioning is based on Wi-Fi and while other
localization alternatives exist, they either require expensive hardware or
provide a low accuracy. This paper presents an investigation into localization
system that leverages signals of broadcasting FM radio stations. The FM
stations provide a worldwide coverage, while FM tuners are readily available in
many mobile devices. The experimental results show that FM radio can be used
for indoor localization, while providing longer battery life than Wi-Fi, making
FM an alternative to consider for positioning.


title: Curvature flows in the sphere

abstract:
  We consider contracting and expanding curvature flows in $\Ss$. When the flow
hypersurfaces are strictly convex we establish a relation between the
contracting hypersurfaces and the expanding hypersurfaces which is given by the
Gau{\ss} map. The contracting hypersurfaces shrink to a point $x_0$ while the
expanding hypersurfaces converge to the equator of the hemisphere $\mc
H(-x_0)$. After rescaling, by the same scale factor, the rescaled hypersurfaces
converge to the unit spheres with centers $x_0$ \resp $-x_0$ exponentially fast
in $C^\un(\Ss[n])$.


title:
Radiation Reaction Effects in Cascade Scattering of Intense, Tightly
  Focused Laser Pulses by Relativistic Electrons

abstract:
  Non-linear cascade scattering of intense, tightly focused laser pulses by
relativistic electrons is studied numerically in the classical approximation
including the radiation damping for the quantum parameter hwx-ray/E<1 and an
arbitrary radiation parameter Kai. The electron energy loss, along with its
side scattering by the ponderomotive force, makes the scattering in the
vicinity of high laser field nearly impossible at high electron energies. The
use of a second, co-propagating laser pulse as a booster is shown to solve this
problem.


title:
Geometric Relationships Between Gaussian and Modulo-Lattice Error
  Exponents

abstract:
  Lattice coding and decoding have been shown to achieve the capacity of the
additive white Gaussian noise (AWGN) channel. This was accomplished using a
minimum mean-square error scaling and randomization to transform the AWGN
channel into a modulo-lattice additive noise channel of the same capacity. It
has been further shown that when operating at rates below capacity but above
the critical rate of the channel, there exists a rate-dependent scaling such
that the associated modulo-lattice channel attains the error exponent of the
AWGN channel. A geometric explanation for this result is developed. In
particular, it is shown how the geometry of typical error events for the
modulo-lattice channel coincides with that of a spherical code for the AWGN
channel.


title:
Kinetic description of thermalization dynamics in weakly interacting
  quantum systems

abstract:
  After a sudden disruption, weakly interacting quantum systems first relax to
a prethermalized state that can be described by perturbation theory and a
generalized Gibbs ensemble. Using these properties of the prethermalized state
we perturbatively derive a kinetic equation which becomes a quantum Boltzmann
equation in the scaling limit of vanishing interaction. Applying this to
interaction quenches in the fermionic Hubbard model we find that the momentum
distribution relaxes to the thermal prediction of statistical mechanics. For
not too large interaction, this two-stage scenario provides a quantitative
understanding of the time evolution leading from the initial pure via a
metastable prethermal to the final thermal state.


title: Pattern Language for Good Old Future From Japanese Culture

abstract:
  Having developed greatly over millennium under its culture, the ancient
buildings and old town atmospheres maintain a quality of comfort. However,
people only appreciate the "good old" quality and do not think further about
the rational reasons why they feel comfort in it. This keeps them from creating
their own things and models with good old quality, relying on the imported
western thinking and methods as a result of modernization. Since people are now
struggling under the imbalanced and complex society, we believe that support is
needed for generating things and frameworks with good old quality in modern
time situations and scenes.


title:
The Course Design To Develop Meta-Cognitive Skills for Collaborative
  Learning Through Tool-Assisted Discourse Analysis

abstract:
  This paper presents the course design titled "Learning Management" of which
the goal is to "learn collaborative learning" for a first-year undergraduate
student. The objective of the class design is to help transform the student's
belief of learning from a passive, individual model to an active, collaborative
model which is supported by the concept of "Knowledge Building" or
"Constructive Interaction". We conducted an empirical study where the students
analyzed their own discourse with KBDeX which is the software they used to
assist their analysis in the experimental group whereas the students in the
control group reflected their project activities in their own way. We examined
the transformation of their beliefs through the qualitative analysis of their
reports after the course. The results showed that the design led to the
transforming of their learning beliefs from "just experiences of the
participation of the collaborative learning" to "active contribution for
collaborative knowledge creation". The course succeeded in changing the
students' preferences about collaborative learning from negative to positive as
well.


title: Holomorphic geometric structures on Kaehler-Einstein manifolds

abstract:
  We prove that the compact Kaehler manifolds with first Chern class
nonnegative that admit holomorphic parabolic geometries are the flat bundles of
rational homogeneous varieties over complex tori. We also prove that the
compact Kaehler manifolds with negative first Chern class that admit
holomorphic cominiscule geometries are the locally Hermitian symmetric
varieties.


title:
At what Rigidity does the Solar Modulation of Galactic Cosmic Rays
  begin?

abstract:
  Observationally, it is difficult to establish at what rigidity the modulation
of galactic cosmic rays (CRs) actually begins in the heliosphere. It should be
possible to do if the relevant local interstellar CR spectra were known and
reliable measurements were made between 10 GV and about 200 GV, inside and
outside the heliosphere. Numerical models for solar modulation studies are
based on simply assuming that CR modulation begins at a given spatial boundary
and at rigidities between 30 to 50 GV, usually handled as an initial condition.
The Stochastic Differential Equations approach to numerical modelling presents
the opportunity to determine the level of modulation from high to low
rigidities because an initial condition at a prescribed high rigidity is not
required. We present the results of such an approach and show the percentage
modulation of CR protons as a function of kinetic energy between 100 MeV and
250 GeV.


title: Witnessing spin-orbit thermal entanglement in rare-earth ions

abstract:
  We explore spin-orbit thermal entanglement in rare-earth ions, based on a
witness obtained from mean energies. The entanglement temperature $T_{E}$,
below which entanglement emerges, is found to be thousands of kelvin above room
temperature for all light rare earths. This demonstrate the robustness to
environmental fluctuations of entanglement between internal degrees of freedom
of a single ion.


title:
Complexity, Chaos, and the Duffing-Oscillator Model: An Analysis of
  Inventory Fluctuations in Markets

abstract:
  Apparently random financial fluctuations often exhibit varying levels of
complexity, chaos. Given limited data, predictability of such time series
becomes hard to infer. While efficient methods of Lyapunov exponent computation
are devised, knowledge about the process driving the dynamics greatly
facilitates the complexity analysis. This paper shows that quarterly inventory
changes of wheat in the global market, during 1974-2012, follow a nonlinear
deterministic process. Lyapunov exponents of these fluctuations are computed
using sliding time windows each of length 131 quarters. Weakly chaotic behavior
alternates with non-chaotic behavior over the entire period of analysis. More
importantly, in this paper, a cubic dependence of price changes on inventory
changes leads to establishment of deterministic Duffing-Oscillator-Model(DOM)
as a suitable candidate for examining inventory fluctuations of wheat. DOM
represents the interaction of commodity production cycle with an external
intervention in the market. Parameters obtained for shifting time zones by
fitting the Fourier estimated time signals to DOM are able to generate
responses that reproduce the true chaotic nature exhibited by the empirical
signal at that time. Endowing the parameters with suitable meanings, one may
infer that temporary changes in speculation reflect the pattern of inventory
volatility that drives the transitions between chaotic and non-chaotic
behavior.


title:
The Highest Recorded Proton Spectrum at Earth since the Beginning of the
  Space Age

abstract:
  The recent solar minimum activity period and the consequent minimum
modulation conditions for cosmic rays were unusual compared to previous solar
minimum periods. The highest spectra of galactic protons (and other cosmic
rays) were recorded by the PAMELA instrument at Earth in late 2009, in contrast
to expectations. The spectrum, between 100 MeV and 50 GeV, for December 2009 is
compared to proton spectra observed during previous solar minimum periods, back
to 1965. Corresponding numerical modeling is presented which predicts that the
next solar minimum spectra could even be higher if similar modulation
conditions then would occur as in 2008-2009. The reason is that incorporating
gradient and curvature drifts in modulation models causes proton spectra for A
> 0 solar magnetic cycles (e.g., around 1976, 1997) to always be higher than
during A < 0 cycles (e.g. around 1965, 1987, 2009) at energies below a few GeV,
if the same modulation conditions would prevail.


title:
A radia\c{c}\~ao de corpo negro e o surgimento da f\'isica qu\^antica:
  Notas de aula

abstract:
  It is shown how the study of blackbody radiation in the early twentieth
century by the German physicist Max Planck gave rise to the quantum theory.


title: Limits on Stringy Signals at the LHC

abstract:
  We explain what features of string theory can be tested at the LHC. We review
the present bounds on the string mass and on extra gauge bosons as well as the
prospects for the upcoming experiments.


title:
Avoiding approximate repetitions with respect to the longest common
  subsequence distance

abstract:
  Ochem, Rampersad, and Shallit gave various examples of infinite words
avoiding what they called approximate repetitions. An approximate repetition is
a factor of the form xx', where x and x' are close to being identical. In their
work, they measured the similarity of x and x' using either the Hamming
distance or the edit distance. In this paper, we show the existence of words
avoiding approximate repetitions, where the measure of similarity between
adjacent factors is based on the length of the longest common subsequence. Our
principal technique is the so-called "entropy compression" method, which has
its origins in Moser and Tardos's algorithmic version of the Lovasz local
lemma.


title: A general method to remove the stiffness of PDEs

abstract:
  A new method to remove the stiffness of partial differential equations is
presented. Two terms are added to the right-hand-side of the PDE : the first is
a damping term and is treated implicitly, the second is of the opposite sign
and is treated explicitly. A criterion for absolute stability is found and the
scheme is shown to be convergent. The method is applied with success to the
mean curvature flow equation, the Kuramoto-Sivashinsky equation, and to the
Rayleigh-Taylor instability in a Hele-Shaw cell, including the effect of
surface tension.


abstract:
  The Institute for Physical Science and Technology at the University of
Maryland was founded in 1976 from a merger of the Institute for Fluid Dynamics
and Applied Mathematics (IFDAM) and the Institute for Molecular Physics (IMP),
which were established at the College Park Campus after World War II to enhance
the expertise of the University of Maryland in some areas of science and
technology of interest to the US Department of Defense. Here I try to
reconstruct the history of the Institute for Molecular Physics at the
University of Maryland.


title: On the structure of vertex cuts separating the ends of a graph

abstract:
  Dinits, Karzanov and Lomonosov showed that the minimal edge cuts of a finite
graph have the structure of a cactus, a tree-like graph constructed from
cycles. Evangelidou and Papasoglu extended this to minimal cuts separating the
ends of an infinite graph. In this paper we show that minimal vertex cuts
separating the ends of a graph can be encoded by a succulent, a mild
generalization of a cactus that is still tree-like. We go on to show that the
earlier cactus results follow from our work.


title:
Poisson-type Multivariate Transfer Function Model Reveals Short-term
  Effects of Ambient Air Pollutants on Hospital Emergency room Visits for
  Cerebro-cardiovascular Diseases

abstract:
  Laboratory experiments have shown that cardiovascular diseases are positively
correlated to the concentration of ambient air pollutants, such as SO2, NO2,
PM10, etc. It has also been repeatedly reported in many countries that
increased concentration of ambient air pollutants leads to rise in hospital
emergency room visitss for these diseases. These studies mainly adopt either
regression analysis or preliminary models in time series analysis, while the
multivariable transfer function model, a relatively newly developed model, has
multiple advantages over the conventional linear regression on analyzing time
series. This study attempts to quantify the association between concentrations
ambient air pollutants and hospital emergency room visitss for
cerebro-cardiovascular diseases in Beijing using a Poisson-type multivariate
transfer function model. The results show that the RR values of SO2, NO2 and
PM10 for a 50 g/m3 increase are 1.129, 1.092 and 1.069 respectively. The lags
for the three pollutants are estimated to be 2 days, 1 day and 1 day
respectively. Compared with the ambient pollutants, daily average temperature
and relative humidity do not influence the daily count of hospital emergency
room visits significantly.


title: Four families of Weyl group orbit functions of B_3 and C_3

abstract:
  The properties of the four families of special functions of three real
variables, called here C-, S-, S^s- and S^l-functions, are studied. The S^s-
and S^l-functions are considered in all details required for their exploitation
in Fourier expansions of digital data, sampled on finite fragment of lattices
of any density and of the 3D symmetry imposed by the weight lattices of B_3 and
C_3 simple Lie algebras/groups. The continuous interpolations, which are
induced by the discrete expansions, are exemplified and compared for some model
functions.


title: Time-dependent modelling of pulsar wind nebulae

abstract:
  A spatially-independent model that can be used to calculate the temporal
evolution of the electron/ positron spectrum in a spherically expanding pulsar
wind nebula is presented. The model is applied to the young nebula G21.5-0.9,
as well as to the unidentified TeV sources HESS J1427-608 and HESS J1507-622.
The parameters derived from the model strengthens the idea that the
unidentified sources can be identified as evolved pulsar wind nebulae.


title: Structure, diffusion and orientational freezing in lithium metasilicate

abstract:
  We report on the dynamic and structural characterization of lithium
metasilicate $Li_2SiO_3$, a network forming ionic glass, by means of molecular
dynamics simulations. The system is characterized by a network of $SiO_4$
tetrahedra disrupted by $Li$ ions which diffuse through the network. Measures
of mean square displacement of $Si$ and $O$ atoms allow us to identify a
temperature at which tetrahedra stop moving relative to each other. This
temperature $T_c\approx 1500\,K$ can be characterized within the framework of
mode coupling theory. At a much lower temperature $T_g\approx 1000\,K$, a
change in the slope of the volume versus temperature data allows to single out
the glass transition. We find signatures of both transitions in structural
order parameters, related to the orientation of tetrahedra. Going down in
temperature we find that, around the mode coupling transition temperature, a
set of order parameters which measure the relative orientation of tetrahedra
cease to increase and stay constant below $T_c$. Another well known measure of
orientational order, the bond orientational order parameter, which in the
studied system measures local order within single tetrahedrons, is found to
continue growing below $T_c$ until $T_g$, below which it remains constant. Our
results allow to relate two characteristic dynamic transitions with
corresponding structural transitions, as observed in two different
orientational order parameters. Furthermore, the results indicate that the
network of thetrahedra continue to relax well below the point where neighboring
tetrahedra cannot rearrange relative to each other, and the glass is reached
only upon a process of relaxation of atoms which form the thetrahedron, as
quantified by the change in the bond orientational order parameters.


title: Generalized Lawson tori and Klein bottles

abstract:
  Using Takahashi theorem we propose an approach to extend known families of
minimal tori in spheres. As an example, the well-known two-parametric family of
Lawson tau-surfaces including tori and Klein bottles is extended to a
three-parametric family of tori and Klein bottles minimally immersed in
spheres. Extremal spectral properties of the metrics on these surfaces are
investigated. These metrics include i) both metrics extremal for the first
non-trivial eigenvalue on the torus, i.e. the metric on the Clifford torus and
the metric on the equilateral torus and ii) the metric maximal for the first
non-trivial eigenvalue on the Klein bottle.


title: Light "Higgs", yet strong interactions

abstract:
  The claimed finding of a light Higgs boson makes the minimal Standard Model
unitary. Yet we recall that the general low-energy dynamics for the minimal
electroweak symmetry breaking sector with three Goldstone bosons and one light
scalar is not so. We construct the effective Lagrangian for these four
particles and their scattering amplitudes, that can be extracted from LHC
experiments when longitudinal W, Z modes be properly isolated for E>>M_W
(Equivalence Theorem). We then observe the known increase in interaction
strength with energy and explore various unitarization methods in the
literature in the absence of other new physics (as LHC experiments fail to
report anything up to 600 GeV). Our generic conclusion is that for most of
parameter space the high energy scattering of the longitudinal W's is strongly
interacting (with the Minimal Standard Model a remarkable exception). We find
and study a second sigma-like scalar pole of the W_L W_L amplitude.


title:
Wigner function approach to single electron coherence in quantum Hall
  edge channels

abstract:
  Recent electron quantum optics experiments performed with on-demand single
electron sources call for a mixed time/frequency approach to electronic quantum
coherence. Here, we present a Wigner function representation of first order
electronic coherence and show that is provides a natural visualization of the
excitations emitted by recently demonstrated single electron sources. It also
gives a unified perspective on single particle and two particle interferometry
experiments. In particular, we introduce a non-classicality criterion for
single electron coherence and discuss it in the context of Mach-Zenhder
interferometry. Finally, the electronic Hanbury Brown and Twiss and the Hong Ou
Mandel experiments are interpreted in terms of overlaps of Wigner function thus
connecting them to signal processing.


title:
Mesoscopic features in the transport properties of a Kondo-correlated
  quantum dot in a magnetic field

abstract:
  We study the transport behavior induced by a small bias voltage through a
quantum dot connected to one-channel finite-size wires. We describe the quantum
dot by the Hubbard-Kondo which is solved by means of a quantum Monte Carlo
method. We investigate the effect of a magnetic field applied at the quantum
dot in the Kondo regime. We identify changes in the behavior of mesoscopic
oscillations introduced by the magnetic field that have an analogous behavior
to those observed as a function of the temperature.


title:
The Age and The Mass of The \alpha Herculis Triple-Star System From A
  MESA Grid of rotating stars with 1.3 <= M/Msun <= 8.0

abstract:
  \alpha^1 Her is the second closest Asymptotic Giant Branch (AGB) star to the
Sun, and the variable luminous M5 Ib-II member of a triple stellar system
containing G8 III and A9 IV-V components. However, the mass of this important
star was previously uncertain with published values ranging from ~2 - 15 Msun.
As shown by this study, its fortuitous membership in a nearby resolved triple
star system, makes it possible to determine its fundamental properties
including its mass and age. We present over twenty years of VRI photometry of
\alpha^1 Her as well as Wing intermediate-band near-IR TiO and NIR continuum
photometry. We introduce a new photometry-based calibration technique, and
extract the effective temperature and luminosity of \alpha^1 Her, in agreement
with recent interferometric measures. We find, Teff=3280 +/- 87 K and
log(L/Lsun)=3.92 +/- 0.14.
  With the MESA code, we calculate a dense grid of evolutionary tracks for
Galactic low- to intermediate-mass (1.3 to 8 Msun) rotating stars from the
pre-main sequence phase to the advanced AGB phase. We include atomic diffusion
and rotation mechanisms to treat the effects of extra elemental mixing. Based
on the observed properties of the \alpha Herculis stars, we constrain the age
of the system to lie in the range 0.41 to 1.25 Gyr. Thus, the mass of \alpha^1
Her lies in the range 2.175 <= M/Msun <= 3.250. We compare our model-based age
inference with recent tracks of the Geneva and STAREVOL codes, and show their
agreement. In the prescribed mass range for \alpha^1 Her, the observed 12C/13C
and 16O/17O ratios are consistent (within 2\sigma) with the ratios predicted by
the MESA, Geneva and STAREVOL codes.


title:
The {\sc Majorana Demonstrator} Neutrinoless Double-Beta Decay
  Experiment

abstract:
  The {\sc Majorana Demonstrator will search for the neutrinoless double-beta
decay of the isotope Ge-76 with a mixed array of enriched and natural germanium
detectors. The observation of this rare decay would indicate the neutrino is
its own antiparticle, demonstrate that lepton number is not conserved, and
provide information on the absolute mass scale of the neutrino. The {\sc
Demonstrator} is being assembled at the 4850-foot level of the Sanford
Underground Research Facility in Lead, South Dakota. The array will be situated
in a low-background environment and surrounded by passive and active shielding.
Here we describe the science goals of the {\sc Demonstrator} and the details of
its design.


title: Chiral dynamics and peripheral transverse densities

abstract:
  In the partonic (or light-front) description of relativistic systems the
electromagnetic form factors are expressed in terms of frame-independent charge
and magnetization densities in transverse space. This formulation allows one to
identify the chiral components of nucleon structure as the peripheral densities
at transverse distances b = O(M_pi^{-1}) and compute them in a parametrically
controlled manner. A dispersion relation connects the large-distance behavior
of the transverse charge and magnetization densities to the spectral functions
of the Dirac and Pauli form factors near the two-pion threshold at timelike t =
4 M_pi^2. Using relativistic chiral effective field theory in the leading-order
approximation, we (a) derive the asymptotic behavior (Yukawa tail) of the
isovector transverse densities in the "chiral" region b = O(M_pi^{-1}) and the
"molecular" region b = O(M_N^2/M_pi^3); (b) perform the heavy-baryon expansion;
(c) explain the relative magnitude of the peripheral charge and magnetization
densities in a simple mechanical picture; (d) include Delta intermediate states
and study the densities in the large-N_c limit of QCD; (e) quantify the spatial
region where the chiral components are numerically dominant; (f) calculate the
chiral divergences of the b^2-weighted moments of the transverse densities
(charge and magnetic radii) and determine their spatial support. Our approach
provides a concise formulation of the spatial structure of the nucleon's chiral
component and offers new insights into basic properties of the chiral
expansion. It relates the information extracted from low-t elastic form factors
to the generalized parton distributions probed in peripheral high-energy
scattering processes.


title:
Top-quark production at the LHC: differential cross section and
  phenomenological applications

abstract:
  We discuss top-quark pair production at hadron colliders and review available
calculations of differential top-pair production cross section in perturbative
QCD at approximate next-to-next-to-leading order (NNLO) within the threshold
resummation formalism. These calculations are implemented into an open source
program under development. We present phenomenological studies at the LHC that
include transverse momentum and rapidity distribution of the top quarks at a
center-of-mass energy of 7 TeV. Preliminary results obtained with this program
are in very good agreement with the recent LHC measurements.


title:
Methods and Results for Standard Model Event Generation at $\sqrt{s}$ =
  14 TeV, 33 TeV and 100 TeV Proton Colliders (A Snowmass Whitepaper)

abstract:
  This document describes the novel techniques used to simulate the common
Snowmass 2013 Energy Frontier Standard Model backgrounds for future hadron
colliders. The purpose of many Energy Frontier studies is to explore the reach
of high luminosity data sets at a variety of high energy colliders. The
generation of high statistics samples which accurately model large integrated
luminosities for multiple center-of-mass energies and pile-up environments is
not possible using an unweighted event generation strategy -- an approach which
relies on event weighting was necessary. Even with these improvements in
efficiency, extensive computing resources were required. This document
describes the specific approach to event generation using Madgraph5 to produce
parton-level processes, followed by parton showering and hadronization with
Pythia6, and pile-up and detector simulation with Delphes3. The majority of
Standard Model processes for pp interactions at $\sqrt(s)$ = 14, 33, and 100
TeV with 0, 50, and 140 additional pile-up interactions are publicly available.


title: Periodicity of the last digits of some combinatorial sequences

abstract:
  In 1962 O. A. Gross proved that the last digits of the Fubini numbers (or
surjective numbers) have a simple periodicity property. We extend this result
to a wider class of combinatorial numbers coming from restricted set
partitions.


title:
Simultaneously continuous retraction and Bishop-Phelps-Bollob\'as type
  theorem

abstract:
  We study the existence of a retraction from the dual space $X^*$ of a (real
or complex) Banach space $X$ onto its unit ball $B_{X^*}$ which is uniformly
continuous in norm topology and continuous in weak-$*$ topology. Such a
retraction is called a uniformly simultaneously continuous retraction.
  It is shown that if $X$ has a normalized unconditional Schauder basis with
unconditional basis constant 1 and $X^*$ is uniformly monotone, then a
uniformly simultaneously continuous retraction from $X^*$ onto $B_{X^*}$
exists. It is also shown that if $\{X_i\}$ is a family of separable Banach
spaces whose duals are uniformly convex with moduli of convexity
$\delta_i(\varepsilon)$ such that $\inf_i \delta_i(\varepsilon)>0$ and $X=
\left[\bigoplus X_i\right]_{c_0}$ or $X=\left[\bigoplus X_i\right]_{\ell_p}$
for $1\le p<\infty$, then a uniformly simultaneously continuous retraction
exists from $X^*$ onto $B_{X^*}$.
  The relation between the existence of a uniformly simultaneously continuous
retraction and the Bishsop-Phelps-Bollob\'as property for operators is
investigated and it is proved that the existence of a uniformly simultaneously
continuous retraction from $X^*$ onto its unit ball implies that a pair $(X,
C_0(K))$ has the Bishop-Phelps-Bollob\'as property for every locally compact
Hausdorff spaces $K$. As a corollary, we prove that $(C_0(S), C_0(K))$ has the
Bishop-Phelps-Bollob\'as property if $C_0(S)$ and $C_0(K)$ are the spaces of
all real-valued continuous functions vanishing at infinity on locally compact
metric space $S$ and locally compact Hausdorff space $K$ respectively.


title: Functional Mellin and Zeta Zeros

abstract:
  A key theorem formulated in the context of functional Mellin transforms
generalizes the important relationship $\exp\mathrm{tr} M=\det\exp M$. Along
with the involution symmetry of the zeta function, the theorem suggests a
strategy for tackling the Riemann hypothesis.


title: Depth-4 Lower Bounds, Determinantal Complexity : A Unified Approach

abstract:
  Tavenas has recently proved that any n^{O(1)}-variate and degree n polynomial
in VP can be computed by a depth-4 circuit of size 2^{O(\sqrt{n}\log n)}. So to
prove VP not equal to VNP, it is sufficient to show that an explicit polynomial
in VNP of degree n requires 2^{\omega(\sqrt{n}\log n)} size depth-4 circuits.
Soon after Tavenas's result, for two different explicit polynomials, depth-4
circuit size lower bounds of 2^{\Omega(\sqrt{n}\log n)} have been proved Kayal
et al. and Fournier et al. In particular, using combinatorial design Kayal et
al.\ construct an explicit polynomial in VNP that requires depth-4 circuits of
size 2^{\Omega(\sqrt{n}\log n)} and Fournier et al.\ show that iterated matrix
multiplication polynomial (which is in VP) also requires 2^{\Omega(\sqrt{n}\log
n)} size depth-4 circuits.
  In this paper, we identify a simple combinatorial property such that any
polynomial f that satisfies the property would achieve similar circuit size
lower bound for depth-4 circuits. In particular, it does not matter whether f
is in VP or in VNP. As a result, we get a very simple unified lower bound
analysis for the above mentioned polynomials.
  Another goal of this paper is to compare between our current knowledge of
depth-4 circuit size lower bounds and determinantal complexity lower bounds. We
prove the that the determinantal complexity of iterated matrix multiplication
polynomial is \Omega(dn) where d is the number of matrices and n is the
dimension of the matrices. So for d=n, we get that the iterated matrix
multiplication polynomial achieves the current best known lower bounds in both
fronts: depth-4 circuit size and determinantal complexity. To the best of our
knowledge, a \Theta(n) bound for the determinantal complexity for the iterated
matrix multiplication polynomial was known only for constant d>1 by Jansen.


title: Compact Binaries Ejected from Globular Clusters as GW Sources

abstract:
  Performing N-body simulations, we examine the dynamics of BH-BH (10 Msun
each) and NS-NS (1.4 Msun each) binaries formed in a cluster and its
implications for gravitational wave detection. A significant fraction of
compact binaries are ejected from a globular cluster after core collapse. Among
the total number of ejected compact objects, 30 per cent of them are in
binaries. Merging time-scales of ejected binaries, which depend on the
cluster's velocity dispersion, are in some cases shorter than the age of the
universe. During the merging event, these dynamically formed compact mergers
are expected to produce gravitational waves that can be detectable by the
advanced ground-based interferometers. Based on our reference assumptions,
merger rates of ejected BH-BH and NS-NS binaries per globular cluster are
estimated to be 2.5 and 0.27 per Gyr, respectively. Assuming the spatial
density of globular clusters to be 8.4 h^3 clusters Mpc^-3 and extrapolating
the merger rate estimates to the horizon distance of the advanced LIGO-Virgo
network, we expect the detection rates for BH-BH and NS-NS binaries with
cluster origin are to be 15 and 0.024 yr^-1, respectively. We find out that
some of the dynamically formed binaries are ejected with a large escape
velocity. They can be responsible for short gamma-ray bursts whose locations
are far from host galaxies.


title: The role of nonmetricity in metric-affine theories of gravity

abstract:
  The intriguing choice to treat alternative theories of gravity by means of
the Palatini approach, namely elevating the affine connection to the role of
independent variable, contains the seed of some interesting (usually
under-explored) generalizations of General Relativity, the metric-affine
theories of gravity. The peculiar aspect of these theories is to provide a
natural way for matter fields to be coupled to the independent connection
through the covariant derivative built from the connection itself. Adopting a
procedure borrowed from the effective field theory prescriptions, we study the
dynamics of metric-affine theories of increasing order, that in the complete
version include invariants built from curvature, nonmetricity and torsion. We
show that even including terms obtained from nonmetricity and torsion to the
second order density Lagrangian, the connection lacks dynamics and acts as an
auxiliary field that can be algebraically eliminated, resulting in some extra
interactions between metric and matter fields.


title:
Improved Lower Bounds for Testing Triangle-freeness in Boolean Functions
  via Fast Matrix Multiplication

abstract:
  Understanding the query complexity for testing linear-invariant properties
has been a central open problem in the study of algebraic property testing.
Triangle-freeness in Boolean functions is a simple property whose testing
complexity is unknown. Three Boolean functions $f_1$, $f_2$ and $f_3:
\mathbb{F}_2^k \to \{0, 1\}$ are said to be triangle free if there is no $x, y
\in \mathbb{F}_2^k$ such that $f_1(x) = f_2(y) = f_3(x + y) = 1$. This property
is known to be strongly testable (Green 2005), but the number of queries needed
is upper-bounded only by a tower of twos whose height is polynomial in $1 /
\epsislon$, where $\epsislon$ is the distance between the tested function
triple and triangle-freeness, i.e., the minimum fraction of function values
that need to be modified to make the triple triangle free. A lower bound of $(1
/ \epsilon)^{2.423}$ for any one-sided tester was given by Bhattacharyya and
Xie (2010). In this work we improve this bound to $(1 / \epsilon)^{6.619}$.
Interestingly, we prove this by way of a combinatorial construction called
\emph{uniquely solvable puzzles} that was at the heart of Coppersmith and
Winograd's renowned matrix multiplication algorithm.


title:
Synthesis and structural ordering of nano-sized Ba3B'Nb2O9 (B'= Ca and
  Zn) powders

abstract:
  In this work we investigated the phase formation and structural ordering of
Ba$_{3}$B$^{'}$Nb$_{2}$O$_{9}$ (B$^{'}$ $=$ Ca and Zn) perovskite powders
obtained by a modified polymeric precursor route using X-ray powder diffraction
and Raman spectroscopy. We obtained single phase complex perovskites at 900
$^o$C. Williamson-Hall analysis and scanning electron microscopy showed that
the powders have crystallites and particles of nanometric size.


title:
Electrochemical Grafting of Naphthylmethyl Radicals to Epitaxial
  Graphene: A Versatile Platform to Reversibly Engineer the Band Structure and
  Transport Properties of Graphene

abstract:
  The Kolbe electrochemical oxidation strategy has been utilized to achieve an
efficient quasireversible electrochemical grafting of the alpha-naphthylmethyl
functional group to graphene. The method facilitates reversible bandgap
engineering in graphene and preparation of electrochemically erasable organic
dielectric films. The picture shows Raman D-band maps of both systems.


title:
Well-temperate phage: optimal bet-hedging against local environmental
  collapses

abstract:
  Upon infection of their bacterial hosts temperate phages must chose between
lysogenic and lytic developmental strategies. Here we apply the game-theoretic
bet-hedging strategy introduced by Kelly to derive the optimal lysogenic
fraction of the total population of phages as a function of frequency and
intensity of environmental downturns affecting the lytic subpopulation.
"Well-temperate" phage from our title is characterized by the best long-term
population growth rate. We show that it is realized when the lysogenization
frequency is approximately equal to the probability of lytic population
collapse. We further predict the existence of sharp boundaries in system's
environmental, ecological, and biophysical parameters separating the regions
where this temperate strategy is optimal from those dominated by purely
virulent or} dormant (purely lysogenic) strategies. We show that the virulent
strategy works best for phages with large diversity of hosts, and access to
multiple independent environments reachable by diffusion. Conversely,
progressively more temperate or even dormant strategies are favored in the
environments, that are subject to frequent and severe temporal downturns.


title: Cosmological Stability Bound in Massive Gravity and Bigravity

abstract:
  We give a simple derivation of a cosmological bound on the graviton mass for
spatially flat FRW solutions in massive gravity with an FRW reference metric
and for bigravity theories. This bound comes from the requirement that the
kinetic term of the helicity zero mode of the graviton is positive definite.
The bound is dependent only on the parameters in the massive gravity potential
and the Hubble expansion rate for the two metrics. We derive the decoupling
limit of bigravity and FRW massive gravity, and use this to give an independent
derivation of the cosmological bound. We recover our previous results that the
tension between satisfying the Friedmann equation and the cosmological bound is
sufficient to rule out all observationally relevant FRW solutions for massive
gravity with an FRW reference metric. In contrast, in bigravity this tension is
resolved due to different nature of the Vainshtein mechanism. We find that in
bigravity theories there exists an FRW solution with late time
self-acceleration for which the kinetic terms for the helicity-2, helicity-1
and helicity-0 are generically nonzero and positive making this a compelling
candidate for a model of cosmic acceleration. We confirm that the generalized
bound is saturated for the candidate partially massless (bi)gravity theories
but the existence of helicity-1/helicity-0 interactions implies the absence of
the conjectured partially massless symmetry for both massive gravity and
bigravity.


title: Transport Regimes in a Double Quantum Dot Device

abstract:
  We analyze the transport properties of a double quantum dot device with both
dots coupled to perfect conducting leads and to a finite chain of N
non-interacting sites connecting both of them. The inter-dot chain strongly
influences the transport across the system and the Local Density of States of
the dots. We study the case of small number of sites, so that Kondo box effects
are present, varying the coupling between the dots and the chain. For odd N and
small coupling between the inter-dot chain and the dots, a state with two
coexisting Kondo regimes develops: the bulk Kondo due to the quantum dots
connected to leads and the one produced by the screening of the quantum dots
spins by the spin in the finite chain at the Fermi level. As the coupling to
the inter-dot chain increases, there is a crossover to a molecular Kondo
effect, due to the screening of the molecule (formed by the finite chain and
the quantum dots) spin by the leads. For even N the two-Kondo temperatures
regime does not develop and the physics is dominated by the usual competition
between Kondo and antiferromagnetism between the quantum dots. We finally study
how the transport properties are affected as N is increased. For the study we
used exact multi-configurational Lanczos calculations and finite U slave-boson
mean-field theory at T = 0. The results obtained with both methods describe
qualitatively and also quantitatively the same physics.


title:
Near threshold angular distributions of the $^2$H$(\gamma,\Lambda)$X
  reaction

abstract:
  A study of the $^2$H$({\gamma},{\Lambda})$X reaction was performed using a
tagged photon beam at the Research Center for Electron Photon Science (ELPH),
Tohoku University. The photoproduced $\Lambda$ was measured in the $p{\pi^{-}}$
decay channel by the upgraded Neutral Kaon Spectrometer (NKS2+). The momentum
integrated differential cross section was determined as a function of the
scatting angle of ${\Lambda}$ in the laboratory frame for five energy bins. Our
results indicated a peak in the cross section at angles smaller than
cos$\theta^{LAB}_{\Lambda}$ = $0.96$. The experimentally obtained angular
distributions were compared to isobar models, Kaon-Maid (KM) and Saclay-Lyon A
(SLA), in addition to the composite Regge-plus-resonance (RPR) model. Both
SLA(r$K_{1}K_{\gamma}$ = $-1.4$) and RPR describe the data quite well in
contrast to the KM model, which substantially under predicted the cross section
at the most forward angles. With the anticipated finalized data on ${\Lambda}$
integrated and momentum dependent differential cross sections of
$^2$H$({\gamma},{\Lambda})$X~\cite{Kaneta_Beckford}, we present our findings on
the angular distributions in this report.


title: Swift observations of 1FGL J1018.6-5856

abstract:
  We report on X-ray properties of the gamma-ray binary 1FGL J1018.6-5856 using
observations obtained with the Swift X-ray telescope. Using 54 observations
made between MJD 55575 and 55984, we find that the X-ray flux is modulated at a
period of 16.57 +/- 0.11 days, consistent with previous reports based on
gamma-ray data. We find that the X-ray maximum at phase 0 previously reported
may not be a persistent feature of the source: the dramatic increases at phase
0 were detected only for ~100 days and not thereafter. Rather, the persistent
sinusoidal maximum seems to be at phase 0.3--0.4, and is misaligned with the
gamma-ray (GeV) peak. We also find evidence that the source's X-ray flux is
correlated with the spectral hardness in the 0.5--10 keV band. Such a
correlation has also been reported in the gamma-ray binaries LS 5039 and LS
I+61d303 and can help us to understand the X-ray emission mechanisms of the
sources.


title: Holographic Vorticity in the Fluid/Gravity Correspondence

abstract:
  The vorticity statistics characterises both the direct and the inverse
turbulent cascades of two-dimensional fluid flows. The fluid/gravity
correspondence relates fluid flows to black brane dynamics. We construct the
holographic vorticity for relativistic and non-relativistic fluids in terms of
the gravitational black brane data, and relate it to the horizon vorticity
expressed as a Weyl scalar. We discuss the statistical scaling structure of the
horizon geometry.


title: Maxima of the Q-index: forbidden 4-cycle and 5-cycle

abstract:
  This paper gives tight upper bounds on the largest eigenvalue q(G) of the
signless Laplacian of graphs with no 4-cycle and no 5-cycle. If n is odd, let
F_{n} be the friendship graph of order n; if n is even, let F_{n} be F_{n-1}
with an edge hanged to its center. It is shown that if G is a graph of order n,
with no 4-cycle, then q(G)<q(F_{n}), unless G=F_{n}. Let S_{n,k} be the join of
a complete graph of order k and an independent set of order n-k. It is shown
that if G is a graph of order n, with no 5-cycle, then q(G)<q(S_{n,2}), unless
G=S_{n,k}. It is shown that these results are significant in spectral extremal
graph problems. Two conjectures are formulated for the maximum q(G) of graphs
with forbidden cycles.


title: Maxima of the Q-index: graphs with bounded clique number

abstract:
  This paper gives a tight upper bound on the spectral radius of the signless
Laplacian of graphs of given order and clique number. More precisely, let G be
a graph of order n, let A be its adjacency matrix, and let D be the diagonal
matrix of the row-sums of A. If G has clique number r, then the largest
eigenvalue q(G) of the matrix Q=A+D satisfies q(G)<= 2(1-1/r)n.
  If G is a complete regular r-partite graph, then equality holds in the above
inequality. This result confirms a conjecture of Hansen and Lucas.


title: Analytic methods for uniform hypergraphs

abstract:
  This paper develops analityc methods for investigating uniform hypergraphs.
Its starting point is the spectral theory of 2-graphs, in particular, the
largest and the smallest eigenvalues of 2-graphs. On the one hand, this simple
setup is extended to weighted r-graphs, and on the other, the
eigenvalues-numbers are generalized to eigenvalues-functions, which encompass
also other graph parameters like Lagrangians and number of edges. The resulting
theory is new even for 2-graphs, where well-settled topics become challenges
again. The paper covers a multitude of topics, with more than a hundred
concrete statements to underpin an analytic theory for hypergraphs. Essential
among these topics are a Perron-Frobenius type theory and methods for extremal
hypergraph problems. Many open problems are raised and directions for possible
further research are outlined.


title: Higgs as a gluon trigger

abstract:
  In the forthcoming high-luminosity phase at the LHC many of the most
interesting measurements for precision QCD studies are hampered by conditions
of large pile-up, particularly at not very high transverse momenta. We study
observables based on measuring ratios of color-singlet currents via Higgs boson
and Drell-Yan production, which may be accessed also at large pile-up, and used
for an experimental program on QCD physics of gluon fusion processes in the LHC
high-luminosity runs. We present results of Monte Carlo calculations for a few
specific examples.


title:
The total mass of super-Brownian motion upon exiting balls and Sheu's
  compact support condition

abstract:
  We study the total mass of a d-dimensional super-Brownian motion as it first
exits an increasing sequence of balls. The process of the total mass is a
time-inhomogeneous continuous-state branching process, where the increasing
radii of the balls are taken as the time parameter. We are able to characterise
its time-dependent branching mechanism and show that it converges, as time goes
to infinity, towards the branching mechanism of the total mass of a
one-dimensional super-Brownian motion as it first crosses above an increasing
sequence of levels. Our results allow us to identify the compact support
criterion given in Sheu (1994) as a classical Grey condition (1974) for the
aforementioned limiting branching mechanism.


title: Quark deconfinement in high-mass neutron stars

abstract:
  In this paper, we explore whether or not quark deconfinement may occur in
high-mass neutron stars such as J1614-2230 (1.97 \pm 0.04 M_Sun) and J0348+0432
(2.01 \pm 0.04 M_Sun). Our study is based on a non-local extension of the SU(3)
Nambu Jona-Lasinio (n3NJL) model with repulsive vector interactions among the
quarks. This model goes beyond the frequently used local version of the Nambu
Jona-Lasinio (NJL) model by accounting for several key features of QCD which
are not part of the local model. Confined hadronic matter is treated in the
framework of non-linear relativistic mean field theory. We find that both the
local as well as the non-local NJL model predict the existence of extended
regions of mixed quark-hadron (quark-hybrid) matter in high-mass neutron stars
with masses of 2.1 to 2.4 M_Sun. Pure quark matter in the cores of neutron
stars is obtained for certain parametrizations of the hadronic lagrangian and
choices of the vector repulsion among quarks. The radii of high-mass neutron
stars with quark-hybrid matter and/or pure quark matter cores in their centers
are found to lie in the canonical range of 12 to 13 km.


title:
Dynamical analysis of anisotropic scalar-field cosmologies for a wide
  range of potentials

abstract:
  We perform a detailed dynamical analysis of anisotropic scalar-field
cosmologies, and in particular of the most significant Kantowski-Sachs, Locally
Rotationally Symmetric (LRS) Bianchi I and LRS Bianchi III cases. We follow the
new and powerful method of $f$-devisers, which allows us to perform the whole
analysis for a wide range of potentials. Thus, one can just substitute the
specific potential form in the final results and obtain the corresponding
behavior, without the need of new calculations. We find a very rich behavior,
and amongst others the universe can result in isotropized solutions with
observables in agreement with observations, such as de Sitter,
quintessence-like, or stiff-dark energy solutions. In particular, all
expanding, accelerating, stable attractors are isotropic. Additionally, we
prove that as long as matter obeys the null energy condition, bounce behavior
is impossible. Finally, applying the general results to the well-studied
exponential and power-law potentials, we find that some of the general stable
solutions disappear. This feature may be an indication that such simple
potentials might restrict the dynamics in scalar-field cosmology, opening the
way to the introduction of more complicated ones.


title: Information content of the weak-charge form factor

abstract:
  Parity-violating electron scattering provides a model-independent
determination of the nuclear weak-charge form factor that has widespread
implications across such diverse areas as fundamental symmetries, nuclear
structure, heavy-ion collisions, and neutron-star structure. We assess the
impact of precise measurements of the weak-charge form factor of ${}^{48}$Ca
and ${}^{208}$Pb on a variety of nuclear observables, such as the neutron skin
and the electric-dipole polarizability. We use the nuclear Density Functional
Theory with several accurately calibrated non-relativistic and relativistic
energy density functionals. To assess the degree of correlation between nuclear
observables and to explore systematic and statistical uncertainties on
theoretical predictions, we employ the chi-square statistical covariance
technique. We find a strong correlation between the weak-charge form factor and
the neutron radius, that allows for an accurate determination of the neutron
skin of neutron-rich nuclei. We determine the optimal range of the momentum
transfer $q$ that maximizes the information content of the measured weak-charge
form factor and quantify the uncertainties associated with the strange quark
contribution. Moreover, we confirm the role of the electric-dipole
polarizability as a strong isovector indicator. Accurate measurements of the
weak-charge form factor of ${}^{48}$Ca and ${}^{208}$Pb will have a profound
impact on many aspects of nuclear theory and hadronic measurements of neutron
skins of exotic nuclei at radioactive-beam facilities.


title: Near-polytropic simulations with a radiative surface

abstract:
  Studies of solar and stellar convection often employ simple polytropic setups
using the diffusion approximation instead of solving the proper radiative
transfer equation. This allows one to control separately the polytropic index
of the hydrostatic reference solution, the temperature contrast between top and
bottom, and the Rayleigh and Peclet numbers. We extend such studies by
including radiative transfer in the gray approximation using a Kramers-like
opacity with freely adjustable coefficients. We study the properties of such
models and compare them with results from the diffusion approximation. We use
the Pencil Code, which is a high-order finite difference code where radiation
is treated using the method of long characteristics. The source function is
given by the Planck function. The opacity is written as kappa=kappa_0 rho^a
T^b, where b is varied from -3.5 to +5, and kappa_0 is varied by four orders of
magnitude. We consider sets of one dimensional models and perform a comparison
with the diffusion approximation. Except for the case where b=5, we find
one-dimensional hydrostatic equilibria with a nearly polytropic stratification
and a polytropic index close to n=(3-b)/(1+a), covering both convectively
stable (n>3/2) and unstable (n<3/2) cases. For b=3 and a=-1, the value of n is
undefined a priori and the actual value of $n$ depends then on the depth of the
domain. For large values of $\kappa_0$, the thermal adjustment time becomes
long, the Peclet and Rayleigh numbers become large, and the temperature
contrast increases and is thus no longer an independent input parameter, unless
the Stefan Boltzmann constant is considered adjustable. Proper radiative
transfer with Kramers-like opacities provides a useful tool for studying
stratified layers with a radiative surface in ways that are more physical than
what is possible with polytropic models using the diffusion approximation.


title:
Site effects in an alpine valley with strong velocity gradient: interest
  and limitations of the 'classical' BEM

abstract:
  Seismic waves may be strongly amplified in deep alluvial basins due to the
velocity contrast (or velocity gradient) between the various layers as well as
the basin edge effects. In this work, the seismic ground motion in a deep
alpine valley (Grenoble basin, French Alps) is investigated through various
'classical' Boundary Element models. This deep valley has a peculiar geometry
("Y"-shaped) and involves a strong velocity gradient between surface geological
structures. In the framework of a numerical benchmark [21-23], a representative
cross section of the valley has been proposed to investigate 2D site effects
through various numerical methods. The 'classical' Boundary Element Method is
considered herein to model the strong velocity gradient with a 2D piecewise
homogeneous medium. For a large incidence angle, the transfer functions
estimated from plane SH waves are close to the one computed with shallow SH
point sources. The fundamental frequency is estimated at 0.33 Hz (SH wave) and
the agreement with previous experimental results (spectral ratios) is good.
Comparisons between 1D and 2D amplification are then performed: the values of
the fundamental frequency and the corresponding amplitude are larger in 2D.
Converting frequency domain results into the time domain, we underline surface
waves generated at the valley edges and the directivity effect for the
amplified wave-field. In the time domain for plane SV-wave, we also computed
the ground motion for a strong seismic event (M=6): time duration and peak
ground velocity are found to be 3 times larger than for the input signal. Such
2D models involving basin effects are then capable to recover the high
amplification level measured in the field. Nevertheless, to deal with complex
3D basins as also proposed in the "ESG" benchmark [21-23], the capabilities of
the classical Boundary Element Method are limited. As shown recently
[43,47,52], such improvements as the fast multipole formulation (FM-BEM) may be
a promising alternative for future 3D simulations.


title:
Spectral approach to the inverse problem for the field of arbitrary
  changing electric dipole

abstract:
  The inverse problem for electromagnetic field produced by arbitrary altered
charge distribution in dipole approximation is solved. The charge distribution
is represented by its dipole moment. It is assumed that the spectral properties
of magnetic field of the dipole are known. The position of the dipole and its
Fourier components are considered as the unknown quantities. It is assumed that
relative increments of amplitude and phase of magnetic field in the vicinity of
the observation point are known. The derived results can be used for study of
phenomena concerned with occurrence and variation of localized electric charge
distribution, when the position and the dynamics of a localized source of
electromagnetic field are to be defined.


title:
Frequency scaling law for nonlinear Compton and Thomson scattering:
  Relevance of spin and polarization effects

abstract:
  The distributions of Compton and Thomson radiation for a shaped laser pulse
colliding with a free electron are calculated in the framework of quantum and
classical electrodynamics, respectively. We introduce a scaling law for the
Compton and the Thomson frequency distributions which universally applies to
long and short incident pulses. Thus, we extend the validity of frequency
scaling postulated in previous studies comparing nonlinear Compton and Thomson
processes. The scaling law introduced in this paper relates the Compton no-spin
flipping process to the Thomson process over nearly the entire spectrum of
emitted radiation, including its high-energy portion. By applying the frequency
scaling, we identify that both spin and polarization effects are responsible
for differences between classical and quantum results. The same frequency
scaling applies to angular distributions and to temporal power distributions of
emitted radiation, which we illustrate numerically.


title:
Constraining white dwarf viscosity through tidal heating in detached
  binary systems

abstract:
  Although the internal structure of white dwarfs is considered to be generally
well understood, the source and entity of viscosity is still very uncertain. We
propose here to study white dwarf viscous properties using short period (< 1
hr), detached white dwarf binaries, such as the newly discovered ~12.8 min
system. These binaries are wide enough that mass transfer has not yet started
but close enough that the least massive component is subject to a measurable
tidal deformation. The associated tidal torque transfers orbital energy, which
is partially converted into heat by the action of viscosity within the deformed
star. As a consequence, its outer non-degenerate layers expand, and the star
puffs up. We self-consistently calculate the fractional change in radius, and
the degree of asynchronism (ratio of stellar to orbital spin) as a function of
the viscous time. Specializing our calculations to J0651, we find that the
discrepancy between the measured radius of the secondary star and He white
dwarf model predictions can be interpreted as tidal inflation if the viscous
timescale is either ~2 10^5 yr or ~10^4 yr. Such values point to a
non-microscopic viscosity, possibly given by tidally induced turbulence, or by
magnetic field stresses with a magnetic field strength of 10-100 Gauss.
Fortunately, these two timescales produce very different degree of
asynchronism, with the shortest one, bringing the system much closer to
synchronisation. A measurement of the stellar spin can thus univocally
determined the mean viscosity. Extrapolating the secondary's radial expansion,
we predict that the star will fill is Roche lobe at a separation which is
1.2-1.3 smaller than the current one. Applying this method to a future sample
of systems can allow us to learn whether viscosity changes with mass and/or
nuclear composition.


title:
Protecting quantum states from decoherence of finite temperature using
  weak measurement

abstract:
  We show how to optimally protect quantum states and quantum entanglement
under non-zero temperature based on measurement reversal from weak measurement.
In particular, we present explicit formulas of the protection.


title: A Very Local Interstellar Spectrum for Galactic Electrons

abstract:
  We present a new local interstellar spectrum for cosmic ray electrons over an
energy range from 1 MeV to 70 GeV. Below (0.8 plus minus 0.2) GeV it has a
power law form, E^-(1.55 plus minus 0.05), with E kinetic energy, which is
consistent with previous studies. This is derived from comparing Voyager 1
electron data observed during 2010 with a comprehensive modulation model.
However, reproducing the PAMELA electron spectrum observed at Earth during late
2006 and to address an unexpected increase in the electron spectrum between
about 2 GeV and up to about 20 GeV, a spectral index of -(3.3 plus minus 0.1)
instead of the reported -(3.18 plus minus 0.05) was found for this energy
range. This feature cannot be caused by solar modulation or any other process
inside the heliosphere.


title: The structure and fate of white dwarf merger remnants

abstract:
  We present a large parameter study where we investigate the structure of
white dwarf (WD) merger remnants after the dynamical phase. A wide range of WD
masses and compositions are explored and we also probe the effect of different
initial conditions. We investigated the degree of mixing between the WDs, the
conditions for detonations as well as the amount of gas ejected. We find that
systems with lower mass ratios have more total angular momentum and as a result
more mass is flung out in a tidal tail. Nuclear burning can affect the amount
of mass ejected. Many WD binaries that contain a helium-rich WD achieve the
conditions to trigger a detonation. In contrast, for carbon-oxygen transferring
systems only the most massive mergers with a total mass above ~2.1 solar masses
detonate. Even systems with lower mass may detonate long after the merger if
the remnant remains above the Chandrasekhar mass and carbon is ignited at the
centre. Finally, our findings are discussed in the context of several possible
observed astrophysical events and stellar systems, such as hot subdwarfs, R
Coronae Borealis stars, single massive white dwarfs, supernovae of type Ia and
other transient events. A large database containing 225 white dwarf merger
remnants is made available via a dedicated web page.


title: Simulating spin-3/2 particles at colliders

abstract:
  Support for interactions of spin-3/2 particles is implemented in the
FeynRules and ALOHA packages and tested with the MadGraph 5 and CalcHEP event
generators in the context of three phenomenological applications. In the first,
we implement a spin-3/2 Majorana gravitino field, as in local supersymmetric
models, and study gravitino and gluino pair-production. In the second, a
spin-3/2 Dirac top-quark excitation, inspired from compositness models, is
implemented. We then investigate both top-quark excitation and top-quark
pair-production. In the third, a general effective operator for a spin-3/2
Dirac quark excitation is implemented, followed by a calculation of the angular
distribution of the s-channel production mechanism.


title:
Confronting Simulations of Optically Thick Gas in Massive Halos with
  Observations at z=2-3

abstract:
  Cosmological hydrodynamic simulations predict the physical state of baryons
in the circumgalactic medium (CGM), which can be directly tested via quasar
absorption line observations. We use high resolution "zoom-in" simulations of
21 galaxies to characterize the distribution of neutral hydrogen around halos
in the mass range M_vir~ 2x10^11 - 4x10^12 M_sun at z~2. We find that both the
mass fraction of cool (T <= 3x10^4 K) gas and the covering fraction of
optically-thick Lyman limit systems (LLSs) depend only weakly on halo mass,
even around the critical value for the formation of stable virial shocks. The
covering fraction of LLSs interior to the virial radius varies between f_c~0.05
- 0.2, with significant scatter among halos. Our simulations of massive halos
(M_vir >= 10^12 M_sun) underpredict the covering fraction of optically-thick
gas observed in the quasar CGM by a large factor. The reason for this
discrepancy is unclear, but several possibilities are discussed. In the lower
mass halos (M_vir >= 5x10^11 M_sun) hosting star-forming galaxies, the
predicted covering factor agrees with observations, however current samples of
quasar-galaxy pairs are too small for a conclusive comparison. To overcome this
limitation, we propose a new observable: the small-scale auto-correlation
function of optically-thick absorbers detected in the foreground of close
quasar pairs. We show that this new observable can constrain the underlying
dark halos hosting LLSs at z~2-3, as well as the characteristic size and
covering factor of the CGM.


title:
Utility of the Weak Temperature Gradient Approximation for Earth-Like
  Tidally Locked Exoplanets

abstract:
  Planets in M dwarf stars' habitable zones are likely to be tidally locked
with orbital periods of order tens of days. This means that the effects of
rotation on atmospheric dynamics will be relatively weak, which requires small
horizontal temperature gradients above the boundary layer of terrestrial
atmospheres. An analytically solvable and dynamically consistent model for
planetary climate with only three free parameters can be constructed by making
the weak temperature gradient (WTG) approximation, which assumes temperatures
are horizontally uniform aloft. The extreme numerical efficiency of a WTG model
compared to a 3D general circulation model (GCM) makes it an optimal tool for
Monte Carlo fits to observables over parameter space. Additionally, such
low-order models are critical for developing physical intuition and coupling
atmospheric dynamics to models of other components of planetary climate. The
objective of this paper is to determine whether a WTG model provides an
adequate approximation of the effect of atmospheric dynamics on quantities
likely to be observed over the next decade. To do this we first tune a WTG
model to GCM output for an Earth-like tidally locked planet with a dry, 1 bar
atmosphere, then generate and compare the expected phase curves of both models.
We find that differences between the two models would be extremely difficult to
detect from phase curves using JWST. This result demonstrates the usefulness of
the WTG approximation when used in conjunction with GCMs as part of a modeling
hierarchy to understand the climate of remote planets.


title:
A Multi-epoch Timing and Spectral Study of the Ultraluminous X-Ray
  Source NGC 5408 X-1 with XMM-Newton

abstract:
  We present results of new XMM-Newton observations of the ultraluminous X-ray
source (ULX) NGC 5408 X-1, one of the few ULXs to show quasi-periodic
oscillations (QPO). We detect QPOs in each of four new (~ 100 ks) pointings,
expanding the range of frequencies observed from 10 - 40 mHz. We compare our
results with the timing and spectral correlations seen in stellar-mass black
hole systems, and find that the qualitative nature of the timing and spectral
behavior of NGC 5408 X-1 is similar to systems in the steep power-law state
exhibiting Type-C QPOs. However, in order for this analogy to quantitatively
hold we must only be seeing the so-called saturated portion of the QPO
frequency - photon index (or disk flux) relation. Assuming this to be the case,
we place a lower limit on the mass of NGC 5408 X-1 of > 800 solar masses.
Alternatively, the QPO frequency is largely independent of the spectral
parameters, in which case a close analogy with the Type-C QPOs in stellar
systems is problematic. Measurement of the source's timing properties over a
wider range of energy spectral index is needed to definitively resolve this
ambiguity. We searched all the available data for both a broad Fe emission line
as well as high frequency QPO analogs (0.1 - 1 Hz), but detected neither. We
place upper limits on the equivalent width of any Fe emission feature in the 6
- 7 keV band, and of the amplitude (rms) of a high frequency QPO analog of
approximately 10 eV and approximately 4%, respectively.


title:
Ferromagnetism of a Repulsive Atomic Fermi Gas in an Optical Lattice: a
  Quantum Monte Carlo Study

abstract:
  Using continuous-space quantum Monte Carlo methods we investigate the
zero-temperature ferromagnetic behavior of a two-component repulsive Fermi gas
under the influence of periodic potentials that describe the effect of a
simple-cubic optical lattice. Simulations are performed with balanced and with
imbalanced components, including the case of a single impurity immersed in a
polarized Fermi sea (repulsive polaron). For an intermediate density below half
filling, we locate the transitions between the paramagnetic, and the partially
and the fully ferromagnetic phases. As the intensity of the optical lattice
increases, the ferromagnetic instability takes place at weaker interactions,
indicating a possible route to observe ferromagnetism in experiments performed
with ultracold atoms. We compare our findings with previous predictions based
on the standard computational method used in material science, namely density
functional theory, and with results based on tight-binding models.


title: Exceptional Form of D=11 Supergravity

abstract:
  Eleven-dimensional supergravity reveals large exceptional symmetries upon
reduction, in accordance with the U-duality groups of M-theory, but their
higher-dimensional geometric origin has remained a mystery. In this letter, we
show that D=11 supergravity can be extended to be fully covariant under the
exceptional groups E_{n(n)}, n=6,7,8. Motivated by a similar formulation of
double field theory we introduce an extended `exceptional spacetime'. We
illustrate the construction by giving the explicit E_{6(6)} covariant form: the
full D=11 supergravity, in a 5+6 splitting of coordinates but without
truncation, embeds into an E_{6(6)} covariant 5+27 dimensional theory. We argue
that this covariant form likewise comprises type IIB supergravity.


title:
Renormalization group equations and matching in a general quantum field
  theory with kinetic mixing

abstract:
  We work out a set of simple rules for adopting the two-loop renormalization
group equations of a generic gauge field theory given in the seminal works of
Machacek and Vaughn to the most general case with an arbitrary number of
Abelian gauge factors and comment on the extra subtleties possibly encountered
upon matching a set of effective gauge theories in such a framework.


title:
The Contribution of Halos with Different Mass Ratios to the Overall
  Growth of Cluster-Sized Halos

abstract:
  We provide a new observational test for a key prediction of the \Lambda CDM
cosmological model: the contributions of mergers with different
halo-to-main-cluster mass ratios to cluster-sized halo growth. We perform this
test by dynamically analyzing seven galaxy clusters, spanning the redshift
range $0.13 < z_c < 0.45$ and caustic mass range $0.4-1.5$ $10^{15}
h_{0.73}^{-1}$ M$_{\odot}$, with an average of 293 spectroscopically-confirmed
bound galaxies to each cluster. The large radial coverage (a few virial radii),
which covers the whole infall region, with a high number of spectroscopically
identified galaxies enables this new study. For each cluster, we identify bound
galaxies. Out of these galaxies, we identify infalling and accreted halos and
estimate their masses and their dynamical states. Using the estimated masses,
we derive the contribution of different mass ratios to cluster-sized halo
growth. For mass ratios between ~0.2 and ~0.7, we find a ~1 $\sigma$ agreement
with \Lambda CDM expectations based on the Millennium simulations I and II. At
low mass ratios, $\lesssim 0.2$, our derived contribution is underestimated
since the detection efficiency decreases at low masses, $\sim 2 \times 10^{14}$
$h_{0.73}^{-1}$ M$_{\odot}$. At large mass ratios, $\gtrsim 0.7$, we do not
detect halos probably because our sample, which was chosen to be quite X-ray
relaxed, is biased against large mass ratios. Therefore, at large mass ratios,
the derived contribution is also underestimated.


title:
The GALEX Arecibo SDSS Survey. VIII. Final Data Release -- The Effect of
  Group Environment on the Gas Content of Massive Galaxies

abstract:
  We present the final data release from the GALEX Arecibo SDSS Survey (GASS),
a large Arecibo program that measured the HI properties for an unbiased sample
of ~800 galaxies with stellar masses greater than 10^10 Msun and redshifts
0.025<z<0.05. This release includes new Arecibo observations for 250 galaxies.
We use the full GASS sample to investigate environmental effects on the cold
gas content of massive galaxies at fixed stellar mass. The environment is
characterized in terms of dark matter halo mass, obtained by cross-matching our
sample with the SDSS group catalog of Yang et al. Our analysis provides, for
the first time, clear statistical evidence that massive galaxies located in
halos with masses of 10^13-10^14 Msun have at least 0.4 dex less HI than
objects in lower density environments. The process responsible for the
suppression of gas in group galaxies most likely drives the observed quenching
of the star formation in these systems. Our findings strongly support the
importance of the group environment for galaxy evolution, and have profound
implications for semi-analytic models of galaxy formation, which currently do
not allow for stripping of the cold interstellar medium in galaxy groups.