title:
Rock physics and geophysics for unconventional resource, multi-component
  seismic, quantitative interpretation

abstract:
  An extension of a previously developed rock physics model is made that
quantifies the relationship between the ductile fraction of a brittle/ductile
binary mixture and the isotropic seismic reflection response. By making a weak
scattering (Born) approximation and plane wave (eikonal) approximation, with a
subsequent ordering according to the angle of incidence, singular value
decomposition analysis are done to understand the stack weightings, number of
stacks, and the type of stacks that will optimally estimate the two fundamental
rock physics parameters. Through this angle ordering, it is found that
effective wavelets can be used for the stacks up to second order. Finally, it
is concluded that the full PP stack and the "full" PS stack are the two optimal
stacks needed to estimate the two rock physics parameters. They dominate over
both the second order AVO "gradient" stack and the higher order (4th order) PP
stack (even at large angles of incidence). Using this result and model based
Bayesian inversion, the detectability of the ductile fraction (shown by others
to be the important quantity for the geomechanical response of unconventional
reservoir fracking) is demonstrated on a model characteristic of the Marcellus
shale play.


title: A model structure on relative dg-Lie algebroids

abstract:
  In this Note, for the future purposes of relative formal derived deformation
theory and of derived coisotropic structures, we prove the existence of a model
structure on the category of dg-Lie algebroids over a cochain differential
non-positively graded commutative algebra over a commutative base ring k of
characteristic 0.


title: Lagrangian stochastic models with specular boundary condition

abstract:
  In this paper, we prove the well-posedness of a conditional McKean Lagrangian
stochastic model endowing the specular boundary condition and the mean
no--permeability condition in smooth bounded confinement domain D. This result
extend our previous work, where we dealt with the case where the confinement
domain is the upper--half plane and where the specular boundary condition is
introduced in generic Langevin process owing to some well known results on the
law of the passage times at zero of the Brownian primitive. The extension to
more general confinement domain exhibit more difficulties that can be handled
by combining stochastic calculus and the analysis of kinetic equations. As a
prerequisite for the nonlinear case, we construct a Langevin process confined
in D and satisfying the specular boundary condition. We then use PDE techniques
to construct the time-marginal densities of the nonlinear process from which we
are able to exhibit the conditional McKean Lagrangian stochastic model.


title: Dimension Four Wins the Same Game as the Standard Model Group

abstract:
  In a previous article Don Bennett and I looked for,found and proposed a game
in which the Standard Model group S(U(2)XU(3)) gets singled out as the
"winner". Here I propose to extend this "game" to construct a corresponding
game between different potential dimensions for space time. The idea is to
formulate how the same competition as the one between the potential gauge
groups would run out, if restricted to the potential Lorentz or Poincare groups
achievable for different dimensions of space time d. The remarkable point is
that it is the experimental dimension of space time 4 which wins. So the same
function defined over Lie groups seems to single out both the gauge group and
the space time dimension in nature. This seems a rather strange coincidence
unless there is really some similar physics behind.


title: On the replica symmetric solution of the K-sat model

abstract:
  In this paper we translate Talagrand's solution of the K-sat model at high
temperature into the language of asymptotic Gibbs measures. Using exact cavity
equations in the infinite volume limit allows us to remove many technicalities
of the inductions on the system size, which clarifies the main ideas of the
proof. This approach also yields a larger region of parameters where the system
is in a pure state and, in particular, for small connectivity parameter we
prove the replica symmetric formula for the free energy at any temperature.


title: Introduction to high dimensional knots

abstract:
  This is an introductory article on high dimensional knots for the beginners.
High dimensional knot theory is an exciting field. It is a field of knot
theory, which is one of topology and is connected with many ones. In this
article we use few literal expressions, equations, functions, etc. We barely
suppose that the readers have studied manifolds, homology theory, or topics
beyond them.
  Is there a nontrivial high dimensional knot? We first answer this question.
After that, we explain local moves on high dimensional knots and the
projections of high dimensional knots.


title:
Low Hole Effective Mass p-type Transparent Conducting Oxides:
  Identification and Design Principles

abstract:
  The development of high performance transparent conducting oxides (TCOs) is
critical to many technologies from transparent electronics to solar cells.
While n-type TCOs are present in many devices, current p-type TCOs are not
largely commercialized as they exhibit much lower carrier mobilities, due to
the large hole effective masses of most oxides. Here, we conduct a
high-throughput computational search on thousands of binary and ternary oxides
and identify several highly promising compounds displaying exceptionally low
hole effective masses (up to an order of magnitude lower than state of the art
p-type TCOs) as well as wide band gaps. In addition to the discovery of
specific compounds, the chemical rationalization of our findings opens new
directions, beyond current Cu-based chemistries, for the design and development
of future p-type TCOs.


title: Discriminants of Chebyshev Radical Extensions

abstract:
  Let t be any integer and fix an odd prime ell. Let Phi(x) = T_ell^n(x)-t
denote the n-fold composition of the Chebyshev polynomial of degree ell shifted
by t. If this polynomial is irreducible, let K = bbq(theta), where theta is a
root of Phi. A theorem of Dedekind's gives a condition on t for which K is
monogenic. For other values of t, we apply the Montes algorithm to obtain a
formula for the discriminant of K and to compute basis elements for the ring of
integers O_K.


title:
V1135 Herculis: a double-lined eclipsing binary with an Anomalous
  Cepheid

abstract:
  BVR light curves and radial velocities for the double-lined eclipsing binary
V1135\,Her were obtained. The brighter component of V1135\,Her is a Cepheid
variable with a pulsation period of 4.22433$\pm$0.00026 days. The orbital
period of the system is about 39.99782$\pm$0.00233 days, which is the shortest
value among the known Type\,II Cepheid binaries. The observed B, V, and R
magnitudes were cleaned for the intrinsic variations of the primary star. The
remaining light curves, consisting of eclipses and proximity effects, are
obtained. Our analyses of the multi-colour light curves and radial velocities
led to the determination of fundamental stellar properties of both components
of the interesting system V1135\,Her. The system consists of two evolved stars,
G1+K3 between giants and supergiants, with masses of M$_1$=1.461$\pm$0.054
\Msun ~and M$_2$=0.504$\pm$0.040 {\Msun} and radii of R$_1$=27.1$\pm$0.4
{\Rsun} and R$_2$=10.4$\pm$0.2 {\Rsun}. The pulsating star is almost filling
its corresponding Roche lobe which indicates the possibility of mass loss or
transfer having taken place. We find an average distance of d=7500$\pm$450 pc
using the BVR magnitudes and also the V-band extinction. Location in the Galaxy
and the distance to the galactic plane with an amount of 1300 pc indicate that
it probably belongs to the thick-disk population. Most of the observed and
calculated parameters of the V1135\,Her and its location on the color-magnitude
and period-luminosity diagrams lead to a classification of an Anomalous
Cepheid.


title: Monte Carlo *-Minimax Search

abstract:
  This paper introduces Monte Carlo *-Minimax Search (MCMS), a Monte Carlo
search algorithm for turned-based, stochastic, two-player, zero-sum games of
perfect information. The algorithm is designed for the class of of densely
stochastic games; that is, games where one would rarely expect to sample the
same successor state multiple times at any particular chance node. Our approach
combines sparse sampling techniques from MDP planning with classic pruning
techniques developed for adversarial expectimax planning. We compare and
contrast our algorithm to the traditional *-Minimax approaches, as well as MCTS
enhanced with the Double Progressive Widening, on four games: Pig, EinStein
W\"urfelt Nicht!, Can't Stop, and Ra. Our results show that MCMS can be
competitive with enhanced MCTS variants in some domains, while consistently
outperforming the equivalent classic approaches given the same amount of
thinking time.


title:
Low-Mass Dark-Matter Hint from CDMS II, Higgs Boson at the LHC, and
  Darkon Models

abstract:
  The CDMS II experiment has observed three events which may have arisen from
weakly interacting massive particle (WIMP) dark matter (DM) with mass of order
9 GeV colliding with nuclei. Although the implied WIMP parameter region seems
to be excluded by limits from the XENON experiments, it is interesting that
most of this tension can go away if the WIMP-nucleon interaction violates
isospin. This motivates us to explore some of the implications for models in
which a real gauge-singlet scalar particle, the darkon, serves as the WIMP,
taking into account the recent discovery of a Higgs boson at the LHC and Planck
determination of the DM relic density. In the simplest scenario, involving only
the standard model plus a darkon, the Higgs boson is largely invisible due to
its decay into a pair of darkons having the WIMP mass suggested by CDMS II and
hence cannot be identified with the one found at the LHC. We find, on the other
hand, that a two-Higgs-doublet model supplemented with a darkon has ample
parameter space to accommodate well both the new potential DM hint from CDMS II
and the Higgs data from the LHC, whether or not the darkon-nucleon interaction
conserves isospin.


title:
Non-commutative localizations of additive categories and weight
  structures; applications to birational motives

abstract:
  In this paper we demonstrate that 'non-commutative localizations' of
arbitrary additive categories (generalizing those defined by Cohn for rings)
are closely (and naturally) related with weight structures. Localizing an
arbitrary triangulated $C$ by a set $S$ of morphisms in the heart of a weight
structure $w$ for it one obtains a triangulated category endowed with a weight
structure $w'$. The heart of $w'$ is a certain idempotent completion of the
non-commutative localization of the heart of $w$ by $S$. The latter is the
natural categorical version of Cohn's localizations of rings i.e. the functor
connecting hearts is universal among all the additive functors that make the
elements of $S$ invertible. In particular, taking $C=K^b(A)$ for an additive
$A$ we obtain a very efficient tool for computing the additive localization of
$A$ by $S$; using it, we generalize the calculations of Gerasimov and
Malcolmson.
  We apply our results to certain categories of birational motives over a base
scheme $U$ (generalizing those defined by Kahn and Sujatha). When $U$ is the
spectrum of a perfect field, the weight structure obtained is compatible with
the Chow and Gersten weight structures defined by the first author in previous
papers. For a general $U$ the result is completely new.
  We also consider the relation of weight structures with their adjacent
t-structures (in localizations). In the 'motivic' setting mentioned this yields
the natural generalization of the 'duality' between birational motives and
birational sheaves with transfers established by Kahn and Sujatha.


title:
k-space Imaging of the Eigenmodes of Sharp Gold Tapers for Scanning
  Near-Field Optical Microscopy

abstract:
  We investigate the radiation patterns of sharp conical gold tapers, designed
as adiabatic nanofocusing probes for scanning near-field optical microscopy
(SNOM). Field calculations show that only the lowest order eigenmode of such a
taper can reach the very apex and thus induce the generation of strongly
enhanced near-field signals. Higher order modes are coupled into the far field
at finite distances from the apex. Here, we demonstrate experimentally how to
distinguish and separate between the lowest and higher order eigenmodes of such
a metallic taper by filtering in the spatial frequency domain. Our approach has
the potential to considerably improve the signal-to-background ratio in
spectroscopic experiments on the nanoscale.


title: A comprehensive picture of baryons in groups and clusters of galaxies

abstract:
  (Abridged) Based on XMM-Newton, Chandra and SDSS data, we investigate the
baryon distribution in groups and clusters and its use as a cosmological
constraint. For this, we considered a sample of 123 systems, with total masses
in the mass range M500 = ~ 10^13 - 4 x 10^15 h_70^-1 Msun.
  The gas masses and total masses are derived from X-ray data under the
assumption of hydrostatic equilibrium and spherical symmetry. The stellar
masses are based on SDSS-DR8 data. For the 37 systems out of 123 that had both
optical and X-ray data available, we investigated the gas, stellar and total
baryon mass fractions inside r2500 and r500, and the differential gas mass
fraction within the spherical annulus between r2500 and r500, as a function of
total mass. For the other objects, we investigated the gas mass fraction only.
We find that the gas mass fraction inside r2500 and r500 depends on the total
mass.
  However, the differential gas mass fraction does not show any dependence on
total mass for systems with M500 > 10^14 Msun. We find that the total baryonic
content increases with cluster mass. This led us to investigate the
contribution of the ICL to the total baryon budget for lower mass systems, but
we find that it cannot account for the difference observed. The gas mass
fraction dependence on total mass observed for groups and clusters could be due
to the difficulty of low-mass systems to retain gas inside the inner region.
Due to their shallower potential well, non-thermal processes are more effective
in expelling the gas from their central regions outwards. Since the
differential gas mass fraction is nearly constant it provides better
constraints for cosmology.
  Using our total f_b estimates, our results imply 0.17 < Omega_m < 0.55.


title: Phase separation on a hyperbolic lattice

abstract:
  We report a preliminary numerical study by kinetic Monte Carlo simulation of
the dynamics of phase separation following a quench from high to low
temperature in a system with a single, conserved, scalar order parameter (a
kinetic Ising ferromagnet) confined to a hyperbolic lattice. The results are
compared with simulations of the same system on two different, Euclidean
lattices, in which cases we observe power-law domain growth with an exponent
near the theoretically known value of 1/3. For the hyperbolic lattice we
observe much slower domain growth, consistent to within our current accuracy
with power-law growth with a much smaller exponent near 0.13. The paper also
includes a brief introduction to non-Euclidean lattices and their mapping to
the Euclidean plane.


title: High precision wavelength estimation method for integrated optics

abstract:
  A novel and simple approach to optical wavelength measurement is presented in
this paper. The working principle is demonstrated using a tunable waveguide
micro ring resonator and single photodiode. The initial calibration is done
with a set of known wavelengths and resonator tunings. The combined spectral
sensitivity function of the resonator and photodiode at each tuning voltage was
modeled by a neural network. For determining the unknown wavelengths, the
resonator was tuned with a set of heating voltages and the corresponding
photodiode signals are collected. The unknown wavelength was estimated, based
on the collected photodiode signals, the calibrated neural networks, and an
optimization algorithm. The wavelength estimate method provides a high spectral
precision of about 8 pm (5*10^(-6) at 1550 nm) in the wavelength range between
1549 nm to 1553 nm. A higher precision of 5 pm (3*10^(-6)) is achieved in the
range between 1550.3 nm to 1550.8 nm, which is a factor of five improved
compared to a simple lookup of data. The importance of our approach is that it
strongly simplifies the optical system and enables optical integration. The
approach is also of general importance, because it may be applicable to all
wavelength monitoring devices which show an adjustable wavelength response.


title: Six-electron semiconductor double quantum dot qubits

abstract:
  We consider a double-quantum-dot (DQD) qubit which contains six electrons
instead of the usual one or two. In this spin qubit, quantum information is
encoded in a low-lying singlet-triplet space much as in the case of a
two-electron DQD qubit. We find that initialization, manipulation, and read-
out can be performed similarly to the two-electron case, and that energy gaps
remain large enough that these operations can be performed robustly. We
consider DQD potentials with parameters chosen to be representative of current
experimental capabilities. Results are obtained using two complementary full
configuration interaction methods.


title:
Demonstration of Achromatic Cold-Neutron Microscope Utilizing
  Axisymmetric Focusing Mirrors

abstract:
  An achromatic cold-neutron microscope with magnification 4 is demonstrated.
The image-forming optics is composed of nested coaxial mirrors of full figures
of revolution, so-called Wolter optics. The spatial resolution, field of view,
and depth of focus are measured and found consistent with ray-tracing
simulations. Methods of increasing the resolution and magnification are
discussed, as well as the scientific case for the neutron microscope. In
contrast to traditional pinhole-camera neutron imaging, the resolution of the
microscope is determined by the mirrors rather than by the collimation of the
beam, leading to possible dramatic improvements in the signal rate and
resolution.


title: The unbearable lightness of being: CDMS versus XENON

abstract:
  The CDMS-II collaboration has reported 3 events in a Si detector, which are
consistent with being nuclear recoils due to scattering of Galactic dark matter
particles with a mass of about 8.6 GeV and a cross-section on neutrons of about
2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has
supposedly ruled out such particles as dark matter, we find by reanalysing the
XENON10 data that this is not the case. Some tension remains however with the
upper limit placed by the XENON100 experiment, independently of astrophysical
uncertainties concerning the Galactic dark matter distribution. We explore
possible ways of ameliorating this tension by altering the properties of dark
matter interactions. Nevertheless, even with standard couplings, light dark
matter is consistent with both CDMS and XENON10/100.


title: Invasive Computing - Common Terms and Granularity of Invasion

abstract:
  Future MPSoCs with 1000 or more processor cores on a chip require new means
for resource-aware programming in order to deal with increasing imperfections
such as process variation, fault rates, aging effects, and power as well as
thermal problems. On the other hand, predictable program executions are
threatened if not impossible if no proper means of resource isolation and
exclusive use may be established on demand. In view of these problems and
menaces, invasive computing enables an application programmer to claim for
processing resources and spread computations to claimed processors dynamically
at certain points of the program execution.
  Such decisions may be depending on the degree of application parallelism and
the state of the underlying resources such as utilization, load, and
temperature, but also with the goal to provide predictable program execution on
MPSoCs by claiming processing resources exclusively as the default and thus
eliminating interferences and creating the necessary isolation between multiple
concurrently running applications. For achieving this goal, invasive computing
introduces new programming constructs for resource-aware programming that
meanwhile, for testing purpose, have been embedded into the parallel computing
language X10 as developed by IBM using a library-based approach.
  This paper presents major ideas and common terms of invasive computing as
investigated by the DFG Transregional Collaborative Research Centre TR89.
Moreoever, a reflection is given on the granularity of resources that may be
requested by invasive programs.


title: Signatures of Hong-Ou-Mandel Interference at Microwave Frequencies

abstract:
  Two-photon quantum interference at a beam splitter, commonly known as
Hong-Ou-Mandel interference, was recently demonstrated with
\emph{microwave-frequency} photons by Lang \emph{et
al.}\,\cite{lang:microwaveHOM}. This experiment employed circuit QED systems as
sources of microwave photons, and was based on the measurement of second-order
cross-correlation and auto-correlation functions of the microwave fields at the
outputs of the beam splitter. Here we present the calculation of these
correlation functions for the cases of inputs corresponding to: (i) trains of
\emph{pulsed} Gaussian or Lorentzian single microwave photons, and (ii)
resonant fluorescent microwave fields from \emph{continuously-driven} circuit
QED systems. The calculations include the effects of the finite bandwidth of
the detection scheme. In both cases, the signature of two-photon quantum
interference is a suppression of the second-order cross-correlation function
for small delays. The experiment described in Ref.
\onlinecite{lang:microwaveHOM} was performed with trains of \emph{Lorentzian}
single photons, and very good agreement between the calculations and the
experimental data was obtained.


title:
Structural and magnetic properties in the quantum S=1/2 dimer systems
  Ba3(Cr1-xVx)2O8 with site disorder

abstract:
  We report a comprehensive study of dc susceptibility, specific heat, neutron
diffraction, and inelastic neutron scattering measurements on polycrystalline
Ba3(Cr1-xVx)2O8 samples, where x=0, 0.06, 0.15, and 0.53. A Jahn-Teller
structure transition occurs for x=0, 0.06, and 0.15 samples and the transition
temperature is reduced upon vanadium substitution from 70(2) K at x=0 to 60(2)
K at x=0.06 and 0.15. The structure becomes less distorted as x increases and
such transition disappears at x=0.53. The observed magnetic excitation spectrum
indicates that the singlet ground state remains unaltered and spin gap energy
\Delta=1.3(1) meV is identical within the instrument resolution for all x. In
addition, the dispersion bandwidth W decreases with increase of x. At x=0.53, W
is reduced to 1.4(1) meV from 2.0(1) meV at x=0.


title:
Nanophononic metamaterial: Thermal conductivity reduction by local
  resonance

abstract:
  We present the concept of a locally resonant nanophononic metamaterial for
thermoelectric energy conversion. Our configuration, which is based on a
silicon thin-film with a periodic array of pillars erected on one or two of the
free surfaces, qualitatively alters the base thin-film phonon spectrum due to a
hybridization mechanism between the pillar local resonances and the underlying
atomic lattice dispersion. Using an experimentally-fitted
lattice-dynamics-based model, we conservatively predict a drop in the
metamaterial thermal conductivity to as low as 50% of the corresponding uniform
thin-film value despite the fact that the pillars add more phonon modes to the
spectrum.


title:
Unanticipated proximity behavior in ferromagnet-superconductor
  heterostructures with controlled magnetic noncollinearity

abstract:
  Magnetization noncollinearity in ferromagnet-superconductor (F/S)
heterostructures is expected to enhance the superconducting transition
temperature (Tc) according to the domain-wall superconductivity theory, or to
suppress Tc when spin-triplet Cooper pairs are explicitly considered. We study
the proximity effect in F/S structures where the F layer is a Sm-Co/Py
exchange-spring bilayer and the S layer is Nb. The exchange-spring contains a
single, controllable and quantifiable domain wall in the Py layer. We observe
an enhancement of superconductivity that is nonmonotonic as the Py domain wall
is increasingly twisted via rotating a magnetic field, different from
theoretical predictions. We have excluded magnetic fields and vortex motion as
the source of the nonmonotonic behavior. This unanticipated proximity behavior
suggests that new physics is yet to be captured in the theoretical treatments
of F/S systems containing noncollinear magnetization.


title:
The generalized Euler-Poinsot rigid body equations: explicit elliptic
  solutions

abstract:
  The classical Euler--Poinsot case of the rigid body dynamics admits a class
of simple but non-trivial integrable generalizations, which modify the Poisson
equations describing the motion of the body in space. These generalizations
possess first integrals which are polynomial in the angular momenta.
  We consider the modified Poisson equations as a system of linear equations
with elliptic coefficients and show that all the solutions of it are
single-valued. By using the vector generalization of the Picard theorem, we
derive the solutions explicitly in terms of sigma functions of the
corresponding elliptic curve. The solutions are accompanied with a numerical
example. We also compare the generalized Poisson equations with % some
generalizations of the classical 3rd order Halphen equation.


title:
Refined Solutions of Time Inhomogeneous Optimal Stopping Games via
  Dirichlet Form

abstract:
  The properties of value functions of time inhomogeneous optimal stopping
problem and zero-sum game (Dynkin game) are studied through time dependent
Dirichlet form. Under the absolute continuity condition on the transition
function of the underlying diffusion process and some other assumptions, the
refined solutions without exceptional starting points are proved to exist, and
the value functions of the optimal stopping and zero-sum game, which are finely
and cofinely continuous, are characterized as the solutions of some variational
inequalities, respectively.


title: Leading Coefficients of Kazhdan--Lusztig Polynomials in Type $D$

abstract:
  Kazhdan--Lusztig polynomials arise in the context of Hecke algebras
associated to Coxeter groups. The computation of these polynomials is very
difficult for examples of even moderate rank. In type $A$ it is known that the
leading coefficient, $\mu(x,w)$ of a Kazhdan--Lusztig polynomial $P_{x,w}$ is
either 0 or 1 when $x$ is fully commutative and $w$ is arbitrary. In type $D$
Coxeter groups there are certain "bad" elements that make $\mu$-value
computation difficult.
  The Robinson--Schensted correspondence between the symmetric group and pairs
of standard Young tableaux gives rise to a way to compute cells of Coxeter
groups of type $A$. A lesser known correspondence exists for signed
permutations and pairs of so-called domino tableaux, which allows us to compute
cells in Coxeter groups of types $B$ and $D$. I will use this correspondence in
type $D$ to compute $\mu$-values involving bad elements. I will conclude by
showing that $\mu(x,w)$ is 0 or 1 when $x$ is fully commutative in type $D$.


title: On Conformal Field Theories With Extremal a/c Values

abstract:
  Unitary conformal field theories (CFTs) are believed to have positive
(non-negative) energy correlators. Energy correlators are universal observables
in higher-dimensional CFTs built out of integrated Wightman functions of the
stress-energy tensor. We analyze energy correlators in parity invariant
four-dimensional CFTs. The goal is to use the positivity of energy correlators
to further constrain unitary CFTs. It is known that the positivity of the
simplest one-point energy correlator implies that 1/3 <= a/c <= 31/18 where a
and c are the Weyl anomaly coefficients. We use the positivity of higher point
energy correlators to show that CFTs with extremal values of a/c have trivial
scattering observables. More precisely, for a/c=1/3 and a/c=31/18 all energy
correlators are fixed to be the ones of the free boson and the free vector
theory correspondingly. Similarly, we show that the positivity and finiteness
of energy correlators together imply that the three-point function of the
stress tensor in a CFT cannot be proportional to the one in the theory of free
boson, free fermion or free vector field.


title: On $K_5$ and $K_{3,3}$-minors of graphs and regular matroids

abstract:
  In this paper we prove two main results about obstruction to graph planarity.
One is that, if $G$ is a 3-connected graph with a $K_5$-minor and $T$ is a
triangle of $G$, then $G$ has a $K_5$-minor $H$, such that $E(T)\cont E(H)$.
  Other is that if $G$ is a 3-connected simple non-planar graph not isomorphic
to $K_5$ and $e,f\in E(G)$, then $G$ has a minor $H$ such that $e,f\in E(H)$
and, up to isomorphisms, $H$ is one of the four non-isomorphic simple graphs
obtained from $K_{3,3}$ by the addiction of \,0, 1 or 2 edges. We generalize
this second result to the class of the regular matroids.


title:
A catalog of 174 binary black-hole simulations for gravitational-wave
  astronomy

abstract:
  This paper presents a publicly available catalog of 174 numerical binary
black-hole simulations following up to 35 orbits. The catalog includes 91
precessing binaries, mass ratios up to 8:1, orbital eccentricities from a few
percent to $10^{-5}$, black-hole spins up to 98% of the theoretical maximum,
and radiated energies up to 11.1% of the initial mass. We establish remarkably
good agreement with post-Newtonian precession of orbital and spin directions
for two new precessing simulations, and we discuss other applications of this
catalog. Formidable challenges remain: e.g., precession complicates the
connection of numerical and approximate analytical waveforms, and vast regions
of the parameter space remain unexplored.


title: Automating the Dispute Resolution in Task Dependency Network

abstract:
  When perturbation or unexpected events do occur, agents need protocols for
repairing or reforming the supply chain. Unfortunate contingency could increase
too much the cost of performance, while breaching the current contract may be
more efficient. In our framework the principles of contract law are applied to
set penalties: expectation damages, opportunity cost, reliance damages, and
party design remedies, and they are introduced in the task dependency model


title: Numerical Solutions in 5D Standing Wave Braneworld

abstract:
  Within the 5D standing wave braneworld model numerical solutions of the
equations for matter fields with various spins are found. It is shown that
corresponding action integrals are factorizable and convergent over the extra
coordinate, i.e. 4D fields are localized on the brane. We find that only left
massless fermions are localized on the brane, while the right fermions are
localized in the bulk. We demonstrate also quantization of Kaluza-Klein excited
modes in our model.


title: Segue 2: The Least Massive Galaxy

abstract:
  Segue 2, discovered by Belokurov et al. (2009), is a galaxy with a luminosity
of only 900 L_sun. We present Keck/DEIMOS spectroscopy of 25 members of Segue
2--a threefold increase in spectroscopic sample size. The velocity dispersion
is too small to be measured with our data. The upper limit with 90% (95%)
confidence is sigma_v < 2.2 (2.6) km/s, the most stringent limit for any
galaxy. The corresponding limit on the mass within the 3-D half-light radius
(46 pc) is M_1/2 < 1.5 (2.1) x 10^5 M_sun. Segue 2 is the least massive galaxy
known. We identify Segue 2 as a galaxy rather than a star cluster based the
wide dispersion in [Fe/H] (from -2.85 to -1.33) among the member stars. The
stars' [alpha/Fe] ratios decline with increasing [Fe/H], indicating that Segue
2 retained Type Ia supernova ejecta despite its presently small mass and that
star formation lasted for at least 100 Myr. The mean metallicity, <[Fe/H]> =
-2.22 +/- 0.13 (about the same as the Ursa Minor galaxy, 330 times more
luminous than Segue 2), is higher than expected from the luminosity-metallicity
relation defined by more luminous dwarf galaxy satellites of the Milky Way.
Segue 2 may be the barest remnant of a tidally stripped, Ursa Minor-sized
galaxy. If so, it is the best example of an ultra-faint dwarf galaxy that came
to be ultra-faint through tidal stripping. Alternatively, Segue 2 could have
been born in a very low-mass dark matter subhalo (v_max < 10 km/s), below the
atomic hydrogen cooling limit.


title: Topological Insulators with Commensurate Antiferromagnetism

abstract:
  We study the topological features of non-interacting insulators subject to an
antiferromangetic (AFM) Zeeman field, or AFM insulators, the period of which is
commensurate with the lattice period. These insulators can be classified by the
presence/absence of an emergent anti-unitary symmetry: the combined operation
of time-reversal and a lattice translation by vector $\mathbf{D}$. For AFM
insulators that preserve this combined symmetry, regardless of any details in
lattice structure or magnetic structure, we show that (i) there is a new type
of Kramers' degeneracy protected by the combined symmetry; (ii) a new $Z_2$
index may be defined for 3D AFM insulators, but not for those in lower
dimensions and (iii) in 3D AFM insulators with a non-trivial $Z_2$ index, there
are odd number of gapless surface modes if and only if the surface termination
also preserves the combined symmetry, but the dispersion of surface states
becomes highly anisotropic if the AFM propagation vector becomes small compared
with the reciprocal lattice vectors. We numerically demonstrate the theory by
calculating the spectral weight of the surface states of a 3D TI in the
presence of AFM fields with different propagation vectors, which may be
observed by ARPES in Bi$_2$Se$_3$ or Bi$_2$Te$_3$ with induced
antiferromagnetism.


title:
The Fermi All-sky Variability Analysis: A list of flaring gamma-ray
  sources and the search for transients in our Galaxy

abstract:
  In this paper we present the Fermi All-sky Variability Analysis (FAVA), a
tool to systematically study the variability of the gamma-ray sky measured by
the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope.
For each direction on the sky, FAVA compares the number of gamma rays observed
in a given time window to the number of gamma rays expected for the average
emission detected from that direction. This method is used in weekly time
intervals to derive a list of 215 flaring gamma-ray sources. We proceed to
discuss the 27 sources found at Galactic latitudes smaller than 10 degrees and
show that, despite their low latitudes, most of them are likely of
extragalactic origin.


title: The impact of bars on disk breaks as probed by S4G imaging

abstract:
  We have analyzed the radial distribution of old stars in a sample of 218
nearby face-on disks, using deep 3.6um images from the Spitzer Survey of
Stellar Structure in Galaxies (S4G). In particular, we have studied the
structural properties of those disks with a broken or down-bending profile. We
find that, on average, disks with a genuine single exponential profile have a
scale-length and a central surface brightness which are intermediate to those
of the inner and outer components of a down-bending disk with the same total
stellar mass. In the case of barred galaxies, the ratio between the break and
the bar radii (Rbr/Rbar) depends strongly on the total stellar mass of the
galaxy. For galaxies more massive than 10^10 Msun, the distribution is bimodal,
peaking at Rbr/Rbar~2 and ~3.5. The first peak, which is the most populated
one, is linked to the Outer Lindblad Resonance of the bar, whereas the second
one is consistent with a dynamical coupling between the bar and the spiral
pattern. For galaxies below 10^10 Msun, breaks are found up to ~10 Rbar, but we
show that they could still be caused by resonances given the rising nature of
rotation curves in these low-mass disks. While not ruling out star formation
thresholds, our results imply that radial stellar migration induced by
non-axysymmetric features can be responsible not only for those breaks at 2
Rbar, but also for many of those found at larger radii.


title:
Asymmetric streaming motion in the Galactic bulge X-shaped structure
  revealed by the OGLE-III proper motions

abstract:
  The Galactic bulge shows a double red clump in sight lines with |b| > 5 deg
and -3 deg < l < 4 deg. It is interpreted as a signature of an X-shaped
structure seen almost edge-on. We measure the proper motions of the stars
belonging to the closer and the further arm of the X-shaped structure. The
intrinsic kinematic properties of the two arms are found by incorporating
information taken from the luminosity function. At b = -5 deg we find that the
proper motion difference between the two arms is a linear function of the
Galactic longitude for -0.1 deg < l < 0.5 deg, which we interpret as a
streaming motion of the stars within the X-shaped structure. Such a streaming
motion has not previously been reported. The proper motion difference is
constant for -0.8 deg < l < -0.1 deg, which gives us an estimate of bulge
rotation speed of 87.9 +/- 8.2 km/s/kpc.


title: Light-like Wilson loops in ABJM and maximal transcendentality

abstract:
  We revisit the computation of the two-loop light-like tetragonal Wilson loop
for three dimensional pure Chern-Simons and N=6 Chern-Simons-matter theory,
within dimensional regularization with dimensional reduction scheme. Our
examination shows that, contrary to prior belief, the result respects maximal
transcendentality as is the case of the four-point scattering amplitude of the
theory. Remarkably, the corrected result matches exactly the scattering
amplitude both in the divergent and in the finite parts, constants included.


title:
Evolution of second generation stars in stellar disks of globular and
  nuclear clusters: Omega Centauri as a test case

abstract:
  Globular clusters (GCs) and many nuclear clusters (NCs) show evidence for
hosting multiple generations of stellar populations. Younger stellar
populations in NCs appear to reside in disk like structures, including the
nuclear cluster in our own Galactic center as well as in M31. Kinematic studies
of the anomalous globular cluster Omega Centauri, thought to possibly be a
former dwarf galaxy (or a galactic nucleus), show evidence for its hosting of a
central, kinematically cold disk component. These observations suggest that
formation of second (or multiple) generation stars may occur in flattened disk
like structures. Here we use detailed N-body simulations to explore the
possible evolution of such stellar disks, embedded in globular clusters. We
follow the long term evolution of a disk like structure similar to that
observed in Omega Centauri and study its properties. We find that a
stellar-disk like origin for second generation stellar populations can leave
behind significant kinematic signatures in properties of the clusters,
including an anisotropic distribution, and lower velocity dispersions, which
can be used to constrain the origin of second generations stars and their
dynamical evolution.


title: The abundance of voids and the excursion set formalism

abstract:
  We present measurements of the number density of voids in the dark matter
distribution from a series of N-body simulations of a \Lambda CDM cosmology. We
define voids as spherical regions of \rho_v = 0.2\rho_m around density minima
in order to relate our results to the predicted abundances using the excursion
set formalism. Using a linear underdensity of \delta_v = -2.7, from a spherical
evolution model, we find that a volume conserving model, which does not
conserve number density in the mapping from the linear to nonlinear regime,
matches the measured abundance to within 16% for a range of void radii 1<
r(Mpc/h)<15. This model fixes the volume fraction of the universe which is in
voids and assumes that voids of a similar size merge as they expand by a factor
of 1.7 to achieve a nonlinear density of \rho_v = 0.2\rho_m today. We find that
the model of Sheth & van de Weygaert (2004) for the number density of voids
greatly overpredicts the abundances over the same range of scales. We find that
the volume conserving model works well at matching the number density of voids
measured from the simulations at higher redshifts, z=0.5 and 1, as well as
correctly predicting the abundances to within 25% in a simulation of a matter
dominated \Omega_m = 1 universe. We examine the abundance of voids in the halo
distribution and find fewer small, r<10 Mpc/h, voids and many more large, r>10
Mpc/h, voids compared to the dark matter. These results indicate that voids
identified in the halo or galaxy distribution are related to the underlying
void distribution in the dark matter in a complicated way which merits further
study if voids are to be used as a precision probe of cosmology.


title:
The Observable Thermal and Kinetic Sunyaev-Zel'dovich Effect in Merging
  Galaxy Clusters

abstract:
  The advent of high-resolution imaging of galaxy clusters using the
Sunyaev-Zel'dovich Effect (SZE) provides a unique probe of the astrophysics of
the intracluster medium (ICM) out to high redshifts. To investigate the effects
of cluster mergers on resolved SZE images, we present a high-resolution
cosmological simulation of a 1.5E15 M_sun adiabatic cluster using the TreeSPH
code ChaNGa. This massive cluster undergoes a 10:3:1 ratio triple merger
accompanied by a dramatic rise in its integrated Compton-Y, peaking at z =
0.05. By modeling the thermal SZE (tSZ) and kinetic SZE (kSZ) spectral
distortions of the Cosmic Microwave Background (CMB) at this redshift with
relativistic corrections, we produce various mock images of the cluster at
frequencies and resolutions achievable with current high-resolution SZE
instruments. The two gravitationally-bound merging subclusters account for 10%
and 1% of the main cluster's integrated Compton-Y, and have extended merger
shock features in the background ICM visible in our mock images. We show that
along certain projections and at specific frequencies, the kSZ CMB intensity
distortion can dominate over the tSZ due to the large line of sight velocities
of the subcluster gas and the unique frequency-dependence of these effects. We
estimate that a one-velocity assumption in estimation of line of sight
velocities of the merging subclusters from the kSZ induces a bias of ~10%. This
velocity bias is small relative to other sources of uncertainty in
observations, partially due to helpful bulk motions in the background ICM
induced by the merger. Our results show that high-resolution SZE observations,
which have recently detected strong kSZ signals in subclusters of merging
systems, can robustly probe the dynamical as well as the thermal state of the
ICM.


title:
Size dependence of the radio luminosity - mechanical power correlation
  in radio galaxies

abstract:
  We examine the relationship between source radio luminosity and kinetic power
in Active Galactic Nucleus (AGN) jets. We show that neglecting various loss
processes can introduce a systematic bias in the jet powers inferred from radio
luminosities for a sample of radio galaxies. This bias can be corrected for by
considering source size as well as radio luminosity; effectively the source
size acts as a proxy for source age. Based on a sample of FR-II radio sources
with jet powers derived from the measured hotspot parameters, we empirically
determine a new expression for jet power that accounts for the source size,
Q_jet / 10^{36} W = 1.5 (L_151 / 10^{27} W/Hz)^{0.8} (1+z)^{1.0} (D /
kpc)^{0.58 \pm 0.17}, where D is source size and L_151 the 151 MHz radio
luminosity. By comparing a flux-limited and volume-limited sample, we show that
any derived radio luminosity - jet power relation depends sensitively on sample
properties, in particular the source size distribution and the size-luminosity
correlation inherent in the sample. Such bias will affect the accuracy of the
kinetic luminosity function derived from lobe radio luminosities and should be
treated with caution.


title:
Accretion Disks Around Binary Black Holes: A Simple GR-Hybrid Evolution
  Model

abstract:
  We consider a geometrically thin, Keplerian disk in the orbital plane of a
binary black hole (BHBH) consisting of a spinning primary and low-mass
secondary (mass ratio q < 1). To account for the principle effects of general
relativity (GR), we propose a modification of the standard Newtonian evolution
equation for the (orbit-averaged) time-varying disk surface density. In our
modified equation the viscous torque in the disk is treated in full GR, while
the tidal torque is handled in the Newtonian limit. Our GR-hybrid treatment is
reasonable because the tidal torque is concentrated near the orbital radius of
the secondary and is most important prior to binary-disk decoupling, when the
orbital separation is large and resides in the weak-field regime. The tidal
torque on the disk diminishes during late merger and vanishes altogether
following merger. By contrast, the viscous torque drives the flow into the
strong-field region and onto the primary during all epochs. Following binary
coalescence, the viscous torque alone governs the time-dependent accretion onto
the remnant, as well as the temporal behavior, strength and spectrum of the
aftermath electromagnetic radiation from the disk. We solve our GR-hybrid
equation for a representative BHBH-disk system, identify several observable EM
signatures of the merger, and compare results obtained for the gas and EM
radiation with those found with the Newtonian prescription.


title: The Case for Massive, Evolving Winds in Black Hole X-ray Binaries

abstract:
  In the last decade, high-resolution X-ray spectroscopy has revolutionized our
understanding of the role of accretion disk winds in black hole X-ray binaries.
Here I present a brief review of the state of wind studies in black hole X-ray
binaries, focusing on recent arguments that disk winds are not only extremely
massive, but also highly variable. I show how new and archival observations at
high timing and spectral resolution continue to highlight the intricate links
between the inner accretion flow, relativistic jets, and accretion disk winds.
Finally, I discuss methods to infer the driving mechanisms of observed disk
winds and their implications for connections between mass accretion and
ejection processes.


title: The Higgs Mass and the Emergence of New Physics

abstract:
  We investigate the physical implications of formulating the electroweak (EW)
part of the Standard Model (SM) in terms of a superconnection involving the
supergroup SU(2/1). In particular, we relate the observed Higgs mass to new
physics at around 4 TeV. The ultraviolet incompleteness of the superconnection
approach points to its emergent nature. The new physics beyond the SM is
associated with the emergent supergroup SU(2/2), which is natural from the
point of view of the Pati-Salam model. Given that the Pati-Salam group is
robust in certain constructions of string vacua, these results suggest a deeper
connection between low energy (4 TeV) and high energy (Planck scale) physics
via the violation of decoupling in the Higgs sector.


title:
Constraining the luminosity function of faint undetected i-dropout
  galaxies

abstract:
  We present a new technique to quantify the light contribution coming from the
faint high redshift ($z\sim6$) galaxies below the detection threshold of
imaging data, set conventionally at S/N=4.5. We illustrate the technique with
an application to Hubble Space Telescope Advanced Camera for Surveys images in
the F775W and F850LP filters of the Ultra Deep Field parallel field NICP12. The
aim of this analysis is to extend by a few magnitudes the faint end of the
luminosity function at $z\sim6$. After masking all the detected sources in the
field we apply a Fast Fourier Transform to obtain the spatial power spectrum of
the background signal. The power spectrum permits us to separate the background
noise signal, the residuals due to the data reduction of the wide field, and
the overall signal produced by faint galaxies. The ratio of the signal in the
i_775 and z_850 bands is used to estimate the contribution of the faint
i-dropout objects. We rely on extensive Monte Carlo simulations to characterize
various sources of uncertainty and quantify the number of faint i-dropout
galaxies in the field. The analysis allows us to put constraints on the
luminosity function at $z\sim6$ down to z_850= 30 mag, 2.5 mag fainter than
with standard techniques on the same data. The data are consistent with a faint
end slope of the luminosity function of $\alpha = -1.9$. Assuming a specific
set of values for the clumping factor, escape fraction, and spectral energy
distribution, we find that the $z\sim6$ undetected galaxies down to z_850=30
mag could have driven cosmic reionization.


title: Gravitational Waves from Oscillon Preheating

abstract:
  Oscillons are long-lived, localized excitations of nonlinear scalar fields
which may be copiously produced during preheating after inflation, leading to a
possible oscillon-dominated phase in the early Universe. For example, this can
happen after axion monodromy inflation, on which we run our simulations. We
investigate the stochastic gravitational wave background associated with an
oscillon-dominated phase. An isolated oscillon is spherically symmetric and
does not radiate gravitational waves, and we show that the flux of
gravitational radiation generated between oscillons is also small. However, a
significant stochastic gravitational wave background may be generated during
preheating itself (i.e, when oscillons are forming), and in this case the
characteristic size of the oscillons is imprinted on the gravitational wave
power spectrum, which has multiple, distinct peaks.


title: Entanglement of three-qubit Greenberger-Horne-Zeilinger-symmetric states

abstract:
  The first characterization of mixed-state entanglement was achieved for
two-qubit states in Werner's seminal work [Phys. Rev. A 40, 4277 (1989)]. A
physically important extension of this result concerns mixtures of a pure
entangled state (such as the Greenberger-Horne-Zeilinger [GHZ] state) and the
completely unpolarized state. These mixed states serve as benchmark for the
robustness of entanglement. They share the same symmetries as the GHZ state. We
call such states GHZ-symmetric. Despite significant progress their multipartite
entanglement properties have remained an open problem. Here we give a complete
description of the entanglement in the family of three-qubit GHZ-symmetric
states and, in particular, of the three-qubit generalized Werner states. Our
method relies on the appropriate parameterization of the states and on the
invariance of entanglement properties under general local operations. An
immediate application of our results is the definition of a symmetrization
witness for the entanglement class of arbitrary three-qubit states.


title:
Microscopic in-medium nucleon-nucleon cross sections with improved Pauli
  blocking effects

abstract:
  We present updated predictions of effective elastic nucleon-nucleon cross
sections intended for use in nucleus-nucleus reactions. A novel characteristic
of the present approach combines all microscopic medium effects included in the
Dirac-Brueckner-Hartree-Fock G-matrix with a Pauli blocking mechanism which is
more appropriate for applications in ion-ion reaction models as compared to a
previous approach. The effective in-medium cross section is found to be quite
sensitive to the description of Pauli blocking in the final configurations.


title: The topological open string wavefunction

abstract:
  We show that, in local Calabi-Yau manifolds, the topological open string
partition function transforms as a wavefunction under modular transformations.
Our derivation is based on the topological recursion for matrix models, and it
generalizes in a natural way the known result for the closed topological string
sector. As an application, we derive results for vevs of 1/2 BPS Wilson loops
in ABJM theory at all genera in a strong coupling expansion, for various
representations.


title:
Timing of ancient human Y lineage depends on the mutation rate: A
  comment on Mendez et al

abstract:
  Mendez et al. recently report the identification of a Y chromosome lineage
from an African American that is an outgroup to all other known Y haplotypes,
and report a time to most recent common ancestor, TMRCA, for human Y lineages
that is substantially longer than any previous estimate. The identification of
a novel Y haplotype is always exciting, and this haplotype, in particular, is
unique in its basal position on the Y haplotype tree. However, at 338 (237-581)
thousand years ago, kya, the extremely ancient TMRCA reported by Mendez et al.
is inconsistent with the known human fossil record (which estimate the age of
anatomically modern humans at 195 +- 5 kya), with estimates from mtDNA (176.6
+- 11.3 kya, and 204.9 (116.8-295.7) kya) and with population genetic theory.
The inflated TMRCA can quite easily be attributed to the extremely low Y
chromosome mutation rate used by the authors.


title:
Soft computing-based calibration of microplane M4 model parameters:
  Methodology and validation

abstract:
  Constitutive models for concrete based on the microplane concept have
repeatedly proven their ability to well-reproduce its non-linear response on
material as well as structural scales. The major obstacle to a routine
application of this class of models is, however, the calibration of
microplane-related constants from macroscopic data. The goal of this paper is
two-fold: (i) to introduce the basic ingredients of a robust inverse procedure
for the determination of dominant parameters of the M4 model proposed by Bazant
and co-workers based on cascade Artificial Neural Networks trained by
Evolutionary Algorithm and (ii) to validate the proposed methodology against a
representative set of experimental data. The obtained results demonstrate that
the soft computing-based method is capable of delivering the searched response
with an accuracy comparable to the values obtained by expert users.


title:
Fault-Tolerant Renormalization Group Decoder for Abelian Topological
  Codes

abstract:
  We present a three-dimensional generalization of a renormalization group
decoding algorithm for topological codes with Abelian anyonic excitations that
we previously introduced for two dimensions. This 3D implementation extends our
previous 2D algorithm by incorporating a failure probability of the syndrome
measurements, i.e., it enables fault-tolerant decoding. We report a
fault-tolerant storage threshold of 1.9(4)% for Kitaev's toric code subject to
a 3D bit-flip channel (i.e. including imperfect syndrome measurements). This
number is to be compared with the 2.9% value obtained via perfect matching. The
3D generalization inherits many properties of the 2D algorithm, including a
complexity linear in the space-time volume of the memory, which can be
parallelized to logarithmic time.


title: Clifford's Theorem for graphs

abstract:
  Let $\Gamma$ be a metric graph having a linear system $g^r_{2r}$ for some $2
\leq r \leq g-2$ then $\Gamma$ has a linear system $g^1_2$. This is similar to
the well-known Clifford's Theorem from the theory of linear systems on smooth
projective curves.


title:
Bounding the decay of oscillatory integrals with a constructible
  amplitude function and a globally subanalytic phase function

abstract:
  We call a function "constructible" if it has a globally subanalytic domain
and can be expressed as a sum of products of globally subanalytic functions and
logarithms of positively-valued globally subanalytic functions. Our main
theorem gives uniform bounds on the decay of parameterized families of
oscillatory integrals with a constructible amplitude function and a globally
subanalytic phase function, assuming that the amplitude function is integrable
and that the phase function satisfies a certain natural condition called the
hyperplane condition. As a simple application of this theorem, we also show
that any continuous, integrable, constructible function of a single variable
has an integrable Fourier transform.


title:
Decoupling of the Right-handed Neutrino Contribution to the Higgs Mass
  in Supersymmetric Models

abstract:
  Recently, it has been argued that in the supersymmetric extension of the
seesaw-extended Standard Model, heavy right-handed neutrinos and sneutrinos may
give corrections as large as a few GeV to the mass of the lightest neutral
CP-even Higgs boson, even if the soft supersymmetry-breaking parameters are of
order the electroweak scale. The presence of such large corrections would
render precise Higgs masses incalculable from measurable low-energy parameters.
We show that this is not the case: decoupling is preserved in the appropriate
sense and right-handed (s)neutrinos, if they exist, have negligible impact on
the physical Higgs masses.


title: Why Does Nature Form Exoplanets Easily?

abstract: The ubiquity of worlds beyond our Solar System confounds us.


title: $k$-protected vertices in binary search trees

abstract:
  We show that for every $k$, the probability that a randomly selected vertex
of a random binary search tree on $n$ nodes is at distance $k-1$ from the
closest leaf converges to a rational constant $c_k$ as $n$ goes to infinity.


title:
Equivalence between Gravitational Mass and Energy for a Quantum Body at
  a Macroscopic Level

abstract:
  We define passive gravitational mass operator of the simplest composite
quantum body - a hydrogen atom - to be proportional to its weight operator in a
weak gravitational field. Although it does not commute with energy operator,
taken in the absence of the field, the equivalence between the expectation
value of passive gravitational mass and energy is shown to survive for
stationary quantum states. All the so-called relativistic corrections to
electron energy in a hydrogen atom are taken into account in the calculations.


title: Uniformly bounded representations and exact groups

abstract:
  We characterize groups with Guoliang Yu's property A (i.e., exact groups) by
the existence of a family of uniformly bounded representations which
approximate the trivial representation.


title:
The varifold representation of non-oriented shapes for diffeomorphic
  registration

abstract:
  In this paper, we address the problem of orientation that naturally arises
when representing shapes like curves or surfaces as currents. In the field of
computational anatomy, the framework of currents has indeed proved very
efficient to model a wide variety of shapes. However, in such approaches,
orientation of shapes is a fundamental issue that can lead to several drawbacks
in treating certain kind of datasets. More specifically, problems occur with
structures like acute pikes because of canceling effects of currents or with
data that consists in many disconnected pieces like fiber bundles for which
currents require a consistent orientation of all pieces. As a promising
alternative to currents, varifolds, introduced in the context of geometric
measure theory by F. Almgren, allow the representation of any non-oriented
manifold (more generally any non-oriented rectifiable set). In particular, we
explain how varifolds can encode numerically non-oriented objects both from the
discrete and continuous point of view. We show various ways to build a Hilbert
space structure on the set of varifolds based on the theory of reproducing
kernels. We show that, unlike the currents' setting, these metrics are
consistent with shape volume (theorem 4.1) and we derive a formula for the
variation of metric with respect to the shape (theorem 4.2). Finally, we
propose a generalization to non-oriented shapes of registration algorithms in
the context of Large Deformations Metric Mapping (LDDMM), which we detail with
a few examples in the last part of the paper.


title: Influence of Electron Evaporative Cooling on Ultracold Plasma Expansion

abstract:
  The expansion of ultracold neutral plasmas (UCP) is driven primarily by the
thermal pressure of the electron component and is therefore sensitive to the
electron temperature. At lower densities (less than 10$^8$ /cm$^3$),
evaporative cooling has a significant influence on the UCP expansion rate. We
studied the effect of electron evaporation in this density range. Owing to the
low density, the effects of three-body recombination were negligible. We
modeled the expansion by taking into account the change in electron temperature
owing to evaporation as well as adiabatic expansion and found good agreement
with our data. We also developed a simple model for initial evaporation over a
range of ultracold plasma densities, sizes, and electron temperatures to
determine over what parameter range electron evaporation is expected to have a
significant effect. We also report on a signal calibration technique, which
relates the signal at our detector to the total number of ions and electrons in
the ultracold plasma.


title: Entanglement entropy in particle decay

abstract:
  The decay of a parent particle into two or more daughter particles results in
an entangled quantum state as a consequence of conservation laws in the decay
process. Recent experiments at Belle and BaBar take advantage of quantum
entanglement and the correlations in the time evolution of the product
particles to study CP and T violations. If one (or more) of the product
particles are not observed, their degrees of freedom are traced out of the pure
state density matrix resulting from the decay, leading to a mixed state density
matrix and an entanglement entropy. This entropy is a measure of the loss of
information present in the original quantum correlations of the entangled
state. We use the Wigner-Weisskopf method to construct an approximation to this
state that evolves in time in a {\em manifestly unitary} way. We then obtain
the entanglement entropy from the reduced density matrix of one of the daughter
particles obtained by tracing out the unobserved states, and follow its time
evolution. We find that it grows over a time scale determined by the lifetime
of the parent particle to a maximum, which when the width of the parent
particle is narrow, describes the phase space distribution of maximally
entangled Bell-like states. The method is generalized to the case in which the
parent particle is described by a wave packet localized in space. Possible
experimental avenues to measure the entanglement entropy in the decay of mesons
at rest are discussed.


title: Coset intersection graphs for groups

abstract:
  Let H, K be subgroups of G. We investigate the intersection properties of
left and right cosets of these subgroups.


title:
Faster identification of optimal contraction sequences for tensor
  networks

abstract:
  The efficient evaluation of tensor expressions involving sums over multiple
indices is of significant importance to many fields of research, including
quantum many-body physics, loop quantum gravity, and quantum chemistry. The
computational cost of evaluating an expression may depend strongly upon the
order in which the index sums are evaluated, and determination of the
operation-minimising contraction sequence for a single tensor network (single
term, in quantum chemistry) is known to be NP-hard. The current preferred
solution is an exhaustive search, using either an iterative depth-first
approach with pruning or dynamic programming and memoisation, but these
approaches are impractical for many of the larger tensor network Ansaetze
encountered in quantum many-body physics. We present a modified search
algorithm with enhanced pruning which exhibits a performance increase of
several orders of magnitude while still guaranteeing identification of an
optimal operation-minimising contraction sequence for a single tensor network.
A reference implementation for MATLAB, compatible with the ncon() and
multienv() network contractors of arXiv:1402.0939 and arXiv:1310.8023
respectively, is supplied.


title:
Asymptotic Joint Distribution of Extreme Sample Eigenvalues and
  Eigenvectors in the Spiked Population Model

abstract:
  In this paper, we consider a data matrix $X_N\in\mathbb{R}^{N\times p}$ where
all the rows are i.i.d. samples in $\mathbb{R}^p$ of mean zero and covariance
matrix $\Sigma\in\mathbb{R}^{p\times p}$. Here the population matrix $\Sigma$
is of finite rank perturbation of the identity matrix. This is the "spiked
population model" first proposed by Johnstone. As $N, p\to\infty$ but $N/p \to
\gamma\in(1, \infty)$, for the sample covariance matrix $S_N := X_NX_N^T/N$, we
establish the joint distribution of the largest and the smallest few packs of
eigenvalues. Inside each pack, they will behave the same as the eigenvalues
drawn from a Gaussian matrix of the corresponding size. Among different packs,
we also calculate the covariance between the Gaussian matrices entries. As a
corollary, if all the rows of the data matrix are Gaussian, then these packs
will be asymptotically independent. Also, the asymptotic behavior of sample
eigenvectors are obtained. Their local fluctuation is also Gaussian with
covariance explicitly calculated.


title:
Periodic perturbations of constrained motion problems on a class of
  implicitly defined manifolds

abstract:
  We study forced oscillations on differentiable manifolds which are globally
defined as the zero set of appropriate smooth maps in some Euclidean spaces.
Given a T-periodic perturbative forcing field, we consider the two different
scenarios of a nontrivial unperturbed force field and of perturbation of the
zero field. We provide simple, degree-theoretic conditions for the existence of
branches of T-periodic solutions. We apply our construction to a class of
second order Differential-Algebraic Equations.


title: The fundamental role of symmetry in nuclear models

abstract:
  The purpose of these lectures is to illustrate how symmetry and pattern
recognition play essential roles in the progression from experimental
observation to an understanding of nuclear phenomena in terms of interacting
neutrons and protons. We do not discuss weak interactions nor relativistic and
sub-nucleon degrees of freedom. The explicit use of symmetry and the power of
algebraic methods, in combination with analytical and geometrical methods are
illustrated by their use in deriving a shell-model description of nuclear
rotational dynamics and the structure of deformed nuclei.


title:
Selling Multiple Correlated Goods: Revenue Maximization and Menu-Size
  Complexity (old title: "The Menu-Size Complexity of Auctions")

abstract:
  We consider the well known, and notoriously difficult, problem of a single
revenue-maximizing seller selling two or more heterogeneous goods to a single
buyer whose private values for the goods are drawn from a (possibly correlated)
known distribution, and whose valuation is additive over the goods. We show
that when there are two (or more) goods, _simple mechanisms_ -- such as selling
the goods separately or as a bundle -- _may yield only a negligible fraction of
the optimal revenue_. This resolves the open problem of Briest, Chawla,
Kleinberg, and Weinberg (JET 2015) who prove the result for at least three
goods in the related setup of a unit-demand buyer. We also introduce the menu
size as a simple measure of the complexity of mechanisms, and show that the
revenue may increase polynomially with _menu size_ and that no bounded menu
size can ensure any positive fraction of the optimal revenue. The menu size
also turns out to "pin down" the revenue properties of deterministic
mechanisms.


title:
VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass
  and specular reflector substrates from room to liquid Argon temperature

abstract:
  The use of efficient wavelength-shifters from the vacuum-ultraviolet to the
photosensor's range of sensitivity is a key feature in detectors for Dark
Matter search and neutrino physics based on liquid argon scintillation
detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface
delimiting the active volume of the detector and/or onto the photosensor
optical window is the most common solution in current and planned experiments.
Detector design and response can be evaluated and correctly simulated only when
the properties of the optical system in use (TPB film + substrate) are fully
understood. Characterization of the optical system requires specific, sometimes
sophisticated optical methodologies. In this paper the main features of TPB
coatings on different, commonly used substrates is reported, as a result of two
independent campaigns of measurements at the specialized optical metrology labs
of ENEA and University of Tor Vergata. Measured features include TPB emission
spectra with lineshape and relative intensity variation recorded as a function
of the film thickness and for the first time down to LAr temperature, as well
as optical reflectance and transmittance spectra of the TPB coated substrates
in the wavelength range of the TPB emission.


title: Minimal Model for an Unbalanced Holographic Superconductor

abstract:
  We describe the simplest holographic model for an s-wave unbalanced
superconductor in 2+1 dimensions. We study its phase diagram and linear
response features with particular attention to the possibility of spatially
modulated phases (LOFF) and mixed spin-electric properties. The normal phase of
the model at hand allows us to analyze a strong-coupling generalization of Mott
two-current model for spintronic systems; the superconducting phase features an
interesting DC spin-superconductivity without spin-symmetry breaking .


title: Phenomenology of scalar leptoquarks

abstract:
  We study the simplest renormalizable scalar leptoquark models where the
standard model is augmented only by one additional scalar representation of
SU(3) x SU(2) x U(1). The requirement that there be no proton decay from
renormalizable interactions singles out two such models, one of which exhibits
an unusual top mass enhancement of the mu -> e gamma decay rate. We analyze the
phenomenology of the model with the unusual top mass enhancement of loop level
chirality changing charged lepton processes in the light of existing and
upcoming experiments. Both of the models that do not allow proton decay from
renormalizable interactions have dimension five operators that, even if
suppressed by the Planck scale, can give rise to an unacceptably high level of
baryon number violation. We discuss symmetries that can forbid these dimension
five operators.


title: Green's function of the cosmological thermalization problem

abstract:
  Energy release in the early Universe leads to spectral distortions of the
cosmic microwave background (CMB) which in the future might allow probing
different physical processes in the pre-recombination (z>~10^3) epoch.
Depending on the energy injection history, the associated distortion partially
thermalizes due to the combined action of Compton scattering, double Compton
scattering and Bremsstrahlung emission, a problem that in general is hard to
solve. Various analytic approximations describing the resulting distortion
exist, however, for small distortions and fixed background cosmology the
Green's function of the problem can be pre-computed numerically. Here we show
that this approach gives very accurate results for a wide range of thermal
histories, allowing fast and quasi-exact computation of the spectral distortion
given the energy release rate. Our method is thus useful for forecasts of
possible constraints on early-universe physics obtained from future
measurements of the CMB spectrum.


title:
Distinguishing different scenarios of early energy release with spectral
  distortions of the cosmic microwave background

abstract:
  Deviations of the cosmic microwave background (CMB) frequency spectrum from a
pure blackbody tell an exciting story about the thermal history of our
Universe. In this paper we illustrate how well future CMB measurements might
decipher this tale, envisioning a PIXIE-like spectrometer, which could improve
the distortion constraints obtained with COBE/FIRAS some 20 years ago by at
least three orders of magnitude. This opens a large discovery space, offering
deep insights to particle and early-universe physics, opportunities that no
longer should be left unexplored. Specifically, we consider scenarios with
annihilating and decaying relic particles, as well as signatures from the
dissipation of primordial small-scale power. PIXIE can potentially rule out
different early-universe scenarios, and moreover will allow unambiguous
detections in many of the considered cases, as we demonstrate here. We also
discuss slightly more futuristic experiments, with several times improved
sensitivities, to highlight the large potential of this new window to the
pre-recombination universe.


title: Relative Noether inequality on fibered surfaces

abstract:
  We prove effective upper bounds on the global sections of nef line bundles of
small generic degree over a fibered surface over a field of any characteristic.
It can be viewed as a relative version of the classical Noether inequality for
surfaces.
  As a consequence, we give a new proof of the slope inequality for fibered
surface without using any stability method. The treatment is essentially
different from these of Xiao, Cornalba--Harris and Moriwaki. We also study the
geography problem of surfaces in positive characteristics and show that the
Severi inequality is true for surfaces of general type in positive
characteristic whose Albanese map is generically finite. Moreover, the
geography of surfaces with Albanese fibrations is studied.


title: Two-Unicast Two-Hop Interference Network: Finite-Field Model

abstract:
  In this paper we present a novel framework to convert the $K$-user multiple
access channel (MAC) over $\FF_{p^m}$ into the $K$-user MAC over ground field
$\FF_{p}$ with $m$ multiple inputs/outputs (MIMO). This framework makes it
possible to develop coding schemes for MIMO channel as done in symbol extension
for time-varying channel. Using aligned network diagonalization based on this
framework, we show that the sum-rate of $(2m-1)\log{p}$ is achievable for a
$2\times 2\times 2$ interference channel over $\FF_{p^m}$. We also provide some
relation between field extension and symbol extension.


title: Origin Scenarios for the Kepler 36 Planetary System

abstract:
  We explore scenarios for the origin of two different density planets in the
Kepler 36 system in adjacent orbits near the 7:6 mean motion resonance. We find
that fine tuning is required in the stochastic forcing amplitude, the migration
rate and planet eccentricities to allow two convergently migrating planets to
bypass mean motion resonances such as the 4:3, 5:4 and 6:5, and yet allow
capture into the 7:6 resonance. Stochastic forcing can eject the system from
resonance causing a collision between the planets, unless the disk inducing
migration and stochastic forcing is depleted soon after resonance capture.
  We explore a scenario with approximately Mars mass embryos originating
exterior to the two planets and migrating inwards toward two planets. We find
that gravitational interactions with embryos can nudge the system out of
resonances. Numerical integrations with about a half dozen embryos can leave
the two planets in the 7:6 resonance. Collisions between planets and embryos
have a wide distribution of impact angles and velocities ranging from
accretionary to disruptive. We find that impacts can occur at sufficiently high
impact angle and velocity that the envelope of a planet could have been
stripped, leaving behind a dense core. Some of our integrations show the two
planets exchanging locations, allowing the outer planet that had experienced
multiple collisions with embryos to become the innermost planet. A scenario
involving gravitational interactions and collisions with embryos may account
for both the proximity of the Kepler 36 planets and their large density
contrast.


title: Coupled-Oscillator Associative Memory Array Operation

abstract:
  Operation of the array of coupled oscillators underlying the associative
memory function is demonstrated for various interconnection schemes
(cross-connect, star phase keying and star frequency keying) and various
physical implementation of oscillators (van der Pol, phase-locked loop, spin
torque). The speed of synchronization of oscillators and the evolution of the
degree of matching is studied as a function of device parameters. The
dependence of errors in association on the number of the memorized patterns and
the distance between the test and the memorized pattern is determined for Palm,
Furber and Hopfield association algorithms.


title:
A tensor approximation method based on ideal minimal residual
  formulations for the solution of high-dimensional problems

abstract:
  In this paper, we propose a method for the approximation of the solution of
high-dimensional weakly coercive problems formulated in tensor spaces using
low-rank approximation formats. The method can be seen as a perturbation of a
minimal residual method with residual norm corresponding to the error in a
specified solution norm. We introduce and analyze an iterative algorithm that
is able to provide a controlled approximation of the optimal approximation of
the solution in a given low-rank subset, without any a priori information on
this solution. We also introduce a weak greedy algorithm which uses this
perturbed minimal residual method for the computation of successive greedy
corrections in small tensor subsets. We prove its convergence under some
conditions on the parameters of the algorithm. The residual norm can be
designed such that the resulting low-rank approximations are quasi-optimal with
respect to particular norms of interest, thus yielding to goal-oriented order
reduction strategies for the approximation of high-dimensional problems. The
proposed numerical method is applied to the solution of a stochastic partial
differential equation which is discretized using standard Galerkin methods in
tensor product spaces.


title:
The potential for photosynthesis in hydrothermal vents: a new avenue for
  life in the Universe?

abstract:
  We perform a quantitative assessment for the potential for photosynthesis in
hydrothermal vents in the deep ocean. The photosynthetically active radiation
in this case is from geothermal origin: the infrared thermal radiation emitted
by hot water, at temperatures ranging from 473 up to 673 K. We find that at
these temperatures the photosynthetic potential is rather low in these
ecosystems for most known species. However, species which a very high
efficiency in the use of light and which could use infrared photons till
1300nm, could achieve good rates of photosynthesis in hydrothermal vents. These
organisms might also thrive in deep hydrothermal vents in other planetary
bodies, such as one of the more astrobiologically promising Jupiter satellites:
Europa.


title: Network Coding-Based Link Failure Recovery over Large Arbitrary Networks

abstract:
  Network coding-based link failure recovery techniques provide near-hitless
recovery and offer high capacity efficiency. Diversity coding is the first
technique to incorporate coding in this field and is easy to implement over
small arbitrary networks. However, its capacity efficiency is restricted by its
systematic coding and high design complexity even though it has lower
complexity than the other coding-based recovery techniques. Alternative
techniques mitigate some of these limitations, but they are difficult to
implement over arbitrary networks. In this paper, we propose a novel
non-systematic coding technique and a simple design algorithm to implement the
diversity coding-based (or network coding-based) recovery over arbitrary
networks. The design framework consists of two parts. An ILP formulation for
each part is developed. The simulation results suggest that both the novel
coding structure and the novel design algorithm lead to higher capacity
efficiency for near-hitless recovery. The new design algorithm is able to
achieve optimal results in large arbitrary networks.


title: Towards independent control of polar and azimuthal anchoring

abstract:
  Monte Carlo simulation, experiment and continuum theory are used to examine
the anchoring exhibited by a nematic liquid crystal at a patterned substrate
comprising a periodic array of rectangles that, respectively, promote vertical
and planar alignment. It is shown that the easy axis and effective anchoring
energy promoted by such surfaces can be readily controlled by adjusting the
design of the pattern. The calculations reveal rich behavior: for strong
anchoring, as exhibited by the simulated system, for rectangle ratios $\geq 2$
the nematic aligns in the direction of the long edge of the rectangles, the
azimuthal anchoring coefficient changing with pattern shape. In weak anchoring
scenarios, however, including our experimental systems, preferential anchoring
is degenerate between the two rectangle diagonals. Bistability between
diagonally-aligned and edge-aligned arrangement is predicted for intermediate
combinations of anchoring coefficient and system length-scale.


title:
Quantum mechanical study of a generic quadratically coupled
  optomechanical system

abstract:
  Typical optomechanical systems involving optical cavities and mechanical
oscillators rely on a coupling that varies linearly with the oscillator
displacement. However, recently a coupling varying instead as the square of the
mechanical displacement has been realized, presenting new possibilities for
non-demolition measurements and mechanical squeezing. In this article we
present a quantum mechanical study of a generic quadratic-coupling
optomechanical Hamiltonian. First, neglecting dissipation, we provide
analytical results for the dressed states, spectrum, phonon statistics and
entanglement. Subsequently, accounting for dissipation, we supply a numerical
treatment using a master equation approach. We expect our results to be of use
to optomechanical spectroscopy, state transfer, wavefunction engineering, and
entanglement generation.


title:
Stability of warped AdS3 black holes in Topologically Massive Gravity
  under scalar perturbations

abstract:
  We demonstrate that the warped AdS3 black hole solutions of Topologically
Massive Gravity are classically stable against massive scalar field
perturbations by analysing the quasinormal and bound state modes of the scalar
field. In particular, it is found that although classical superradiance is
present it does not give rise to superradiant instabilities. The stability is
shown to persist even when the black hole is enclosed by a stationary mirror
with Dirichlet boundary conditions. This is a surprising result in view of the
similarity between the causal structure of the warped AdS3 black hole and the
Kerr spacetime in 3+1 dimensions. This work provides the foundations for the
study of quantum field theory in this spacetime.


title:
Application of a conservative, generalized multiscale finite element
  method to flow models

abstract:
  In this paper we propose a method for the construction of locally
conservative flux fields from Generalized Multiscale Finite Element Method
(GMsFEM) pressure solutions. The flux values are obtained from an element-based
postprocessing procedure in which an independent set of 4x4 linear systems need
to be solved. To test the performance of the method we consider two
heterogeneous permeability coefficients and couple the resulting fluxes to a
two-phase flow model. The increase in accuracy associated with the computation
of the GMsFEM pressure solutions is inherited by the postprocessed flux fields
and saturation solutions, and is closely correlated to the size of the
reduced-order systems. In particular, the addition of more basis functions to
the enriched coarse space yields solutions that more accurately capture the
behavior of the fine scale model. A number of numerical examples are offered to
validate the performance of the method.


title:
On Maximal Correlation, Hypercontractivity, and the Data Processing
  Inequality studied by Erkip and Cover

abstract:
  In this paper we provide a new geometric characterization of the
Hirschfeld-Gebelein-R\'{e}nyi maximal correlation of a pair of random $(X,Y)$,
as well as of the chordal slope of the nontrivial boundary of the
hypercontractivity ribbon of $(X,Y)$ at infinity. The new characterizations
lead to simple proofs for some of the known facts about these quantities. We
also provide a counterexample to a data processing inequality claimed by Erkip
and Cover, and find the correct tight constant for this kind of inequality.


title: Quantum Drinfeld Orbifold Algebras

abstract:
  Quantum Drinfeld orbifold algebras are the generalizations of Drinfeld
orbifold algebras, which are obtained by replacing polynomial rings by quantum
polynomial rings. Shepler and Witherspoon in their paper, give necessary and
sufficient conditions on a defining parameters to obtain Drinfeld orbifold
algebras. In this article we generalize their result. It also simultaneously
generalizes the result of Levandovskyy and Shepler about quantum Drinfeld Hecke
algebras.


title: Uncertainty principle on weighted spheres, balls and simplexes

abstract:
  For a family of weight functions $h_\kappa$ that are invariant under a
reflection group, the uncertainty principle on the unit sphere in the form of
$$
  \min_{1 \le i \le d} \int_{\mathbb{S}^{d-1}} (1- x_i) |f(x)|^2 h_\kappa^2(x)
d\sigma \int_{\mathbb{S}^{d-1}}\left |\nabla_0 f(x)\right |^2 h_\kappa^2(x)
d\sigma \ge c $$ is established for invariant functions $f$ that have unit norm
and zero mean, where $\nabla_0$ is the spherical gradient. In the same spirit,
uncertainty principles for weighted spaces on the unit ball and on the standard
simplex are established, some of them hold for all admissible functions instead
of invariant functions.


title:
Three-dimensional brittle fracture: configurational-force-driven crack
  propagation

abstract:
  This paper presents a computational framework for quasi-static brittle
fracture in three dimensional solids. The paper set outs the theoretical basis
for determining the initiation and direction of propagating cracks based on the
concept of configurational mechanics, consistent with Griffith's theory.
Resolution of the propagating crack by the finite element mesh is achieved by
restricting cracks to element faces and adapting the mesh to align it with the
predicted crack direction. A local mesh improvement procedure is developed to
maximise mesh quality in order to improve both accuracy and solution robustness
and to remove the influence of the initial mesh on the direction of propagating
cracks. An arc-length control technique is derived to enable the dissipative
load path to be traced. A hierarchical hp-refinement strategy is implemented in
order to improve both the approximation of displacements and crack geometry.
The performance of this modelling approach is demonstrated on two numerical
examples that qualitatively illustrate its ability to predict complex crack
paths. All problems are three-dimensional, including a torsion problem that
results in the accurate prediction of a doubly-curved crack.


title: The Fermi Bubbles as Starburst Wind Termination Shocks

abstract:
  The enhanced star formation in the inner 100 pc of the Galaxy launches a
superwind at ~1600 km s$^{-1}$ for M82-like parameters. The ram pressure of the
wind is very low compared to more powerful starburst winds. I show that halo
gas stops the wind a few kpc from the Galactic Centre. I suggest that the
termination shock accelerates cosmic rays, and that the resulting Inverse
Compton gamma rays are visible as the Fermi Bubbles. The Bubbles are then wind
bubbles, which the starburst can inflate within 10 Myr. They can remain in
steady state as long as the starburst lasts. The shock may accelerate PeV
electrons and EeV protons. The Bubbles may be analogues of galactic wind
termination shocks in the intergalactic medium. I discuss the advantages and
problems of this model. I note that any jets from Sgr A* must burrow through
the starburst wind bubble before reaching the halo gas, which could affect the
early evolution of such jets.


title: Quantization Domains

abstract:
  We study the quantization of certain classical field theories using
reflection positivity. We give elementary conditions that ensure the resulting
vacuum state is cyclic for products of quantum field operators, localized in a
bounded Euclidean space-time region O at positive time. We call such a domain a
quantization domain for the classical field. The fact that bounded regions are
quantization domains in classical field theory is similar to the
"Reeh-Schlieder" property in axiomatic quantum field theory.


title: Optimal Control for a Steady State Dead Oil Isotherm Problem

abstract:
  We study the optimal control of a steady-state dead oil isotherm problem. The
problem is described by a system of nonlinear partial differential equations
resulting from the traditional modelling of oil engineering within the
framework of mechanics of a continuous medium. Existence and regularity results
of the optimal control are proved, as well as necessary optimality conditions.


title:
Branching random walks in random environment and super-Brownian motion
  in random environment

abstract:
  We focus on the existence and characterization of the limit for a certain
critical branching random walks in time-space random environment in one
dimension which was introduced by M. Birnkenr et.al. Each particle performs
simple random walk on $\mathbb{Z}$ and branching mechanism depends on the
time-space site. The weak limit of this measure valued processes is
characterized as a solution to the non-trivial martingale problem and called
super-Brownian motions in random environment by L. Mytnik. Moreover, we will
show the weak uniqueness of the solutions with some initial condition.


title: The classification of subfactors of index at most 5

abstract:
  A subfactor is an inclusion $N \subset M$ of von Neumann algebras with
trivial centers. The simplest example comes from the fixed points of a group
action $M^G \subset M$, and subfactors can be thought of as fixed points of
more general group-like algebraic structures. These algebraic structures are
closely related to tensor categories and have played important roles in knot
theory, quantum groups, statistical mechanics, and topological quantum field
theory. There's a measure of size of a subfactor, called the index. Remarkably
the values of the index below 4 are quantized, which suggests that it may be
possible to classify subfactors of small index. Subfactors of index at most 4
were classified in the '80s and early '90s. The possible index values above 4
are not quantized, but once you exclude a certain family it turns out that
again the possibilities are quantized. Recently the classification of
subfactors has been extended up to index 5, and (outside of the infinite
families) there are only 10 subfactors of index between 4 and 5. We give a
summary of the key ideas in this classification and discuss what is known about
these special small subfactors.


title:
The Ultimate Fate of Cosmic Rays from Galaxies and their Role in the
  Intergalactic Medium

abstract:
  The majority of cosmic rays (CRs) generated by star-forming galaxies escape
them and enter the intergalactic medium (IGM). Galactic wind termination shocks
might also accelerate CRs. I show that the mean pressure of these CRs can reach
to within an order of magnitude of the mean Lyman-alpha forest thermal
pressure. At z >~ 1, their pressure may have even been dominant. I also
demonstrate that, whichever IGM phase the CRs reside in, they contribute
significantly to its pressure if its temperature is ~$10^4$ K, as long as
pionic and Coulomb losses are negligible. Where CRs end up depends on the
structure and strength of intergalactic magnetic fields. I argue that CRs end
up at least 30 kpc from their progenitor galaxies. CRs may self-confine in the
IGM to the sound speed, generating >~ $10^{-13}$ G magnetic fields. These
considerations imply the existence and importance of a nonthermal IGM.


title:
Modeling Smectic Layers in Confined Geometries: Order Parameter and
  Defects

abstract:
  We identify problems with the standard complex order parameter formalism for
smectic-A (SmA) liquid crystals, and discuss possible alternative descriptions
of smectic order. In particular, we suggest an approach based on the real
smectic density variation rather than a complex order parameter. This approach
gives reasonable numerical results for the smectic layer configuration and
director field in sample geometries, and can be used to model smectic liquid
crystals under nanoscale confinement for technological applications.


title: An Example of J-unitary Operator. Solving a Problem Stated by M.G. Krein

abstract:
  Theorem 1.
  Given a number c >= 1, there exists a J-unitary operator \hat{V}, such that:
  (a) r(\hat{V})= r(\hat{V}^{-1})= c ;
  (b) S(c^{-1}\hat{V})=S(c^{-1}\hat{V}^{-1})
  =S(c^{-1}\hat{V}^{*-1}) = S(c^{-1}\hat{V}^*)={0}
  (c) there exist maximal strictly positive and strictly negative
  \hat{V}^{\pm 1}-{invariant subspaces}
  L_{+}, L_{-}, such that they are mutually J-orthogonal and
  L_{+} + L_{-} is dense in the space.
  (d_1) if L_1 is non-zero \hat{V}-invariant subspace, then
r(\hat{V}|L_1)=r(\hat{V})
  (d_2) if L_2 is non-zero \hat{V}^{-1}-invariant subspace, then
r(\hat{V}^{-1}|L_2)=r(\hat{V}^{-1}) .


title:
Finite temperature study of the axial U(1) symmetry on the lattice with
  overlap fermion formulation

abstract:
  We examine the axial U(1) symmetry near and above the finite temperature
phase transition in two-flavor QCD using lattice QCD simulations. Although the
axial U(1) symmetry is always violated by quantization, (i.e.) the chiral
anomaly, the correlation functions may manifest effective restoration of the
symmetry in the high temperature phase. We explicitly study this possibility by
calculating the meson correlators as well as the Dirac operator spectral
density near the critical point. Our numerical simulations are performed on a
$16^3\times 8$ lattice with two flavors of dynamical quarks represented by the
overlap fermion formalism. Chiral symmetry and its violation due to the axial
anomaly is manifestly realized with this formulation, which is a prerequisite
for the study of the effective restoration of the axial U(1) symmetry. In order
to avoid discontinuity in the gauge configuration space, which occurs for the
exactly chiral lattice fermions, the simulation is confined in a fixed
topological sector. It induces finite volume effect, which is well described by
a formula based on the Fourier transform from the $\theta$-vacua. We confirm
this formula at finite temperature by calculating the topological
susceptibility in the quenched theory. Our two flavor simulations show
degeneracy of the meson correlators and a gap in the Dirac operator spectral
density, which implies that the axial U(1) symmetry is effectively restored in
the chirally symmetric phase.


title: Manipulation in Clutter with Whole-Arm Tactile Sensing

abstract:
  We begin this paper by presenting our approach to robot manipulation, which
emphasizes the benefits of making contact with the world across the entire
manipulator. We assume that low contact forces are benign, and focus on the
development of robots that can control their contact forces during
goal-directed motion. Inspired by biology, we assume that the robot has
low-stiffness actuation at its joints, and tactile sensing across the entire
surface of its manipulator. We then describe a novel controller that exploits
these assumptions. The controller only requires haptic sensing and does not
need an explicit model of the environment prior to contact. It also handles
multiple contacts across the surface of the manipulator. The controller uses
model predictive control (MPC) with a time horizon of length one, and a linear
quasi-static mechanical model that it constructs at each time step. We show
that this controller enables both real and simulated robots to reach goal
locations in high clutter with low contact forces. Our experiments include
tests using a real robot with a novel tactile sensor array on its forearm
reaching into simulated foliage and a cinder block. In our experiments, robots
made contact across their entire arms while pushing aside movable objects,
deforming compliant objects, and perceiving the world.


title: Rings of Frobenius operators

abstract:
  Let R be a local ring of prime characteristic. We study the ring of Frobenius
operators F(E), where E is the injective hull of the residue field of R. In
particular, we examine the finite generation of F(E) over its degree zero
component, and show that F(E) need not be finitely generated when R is a
determinantal ring; nonetheless, we obtain concrete descriptions of F(E) in
good generality that we use, for example, to prove the discreteness of
F-jumping numbers for arbitrary ideals in determinantal rings.