title: Dimension of uniformly random self-similar fractals

abstract:
  We calculate the almost sure Hausdorff dimension of uniformly random
self-similar fractals. These random fractals are generated from a finite family
of similarities, where the linear parts of the mappings are independent
uniformly distributed random variables at each step of iteration. We also prove
that the Lebesgue measure of such sets is almost surely positive in some cases.


title:
Stability and collapse of fermions in a binary dipolar boson-fermion
  164Dy-161Dy mixture

abstract:
  We suggest a time-dependent mean-field hydrodynamic model for a binary
dipolar boson-fermion mixture to study the stability and collapse of fermions
in the $^{164}$Dy-$^{161}$Dy mixture. The condition of stability of the dipolar
mixture is illustrated in terms of phase diagrams. A collapse is induced in a
disk-shaped stable binary mixture by jumping the interspecies contact
interaction from repulsive to attractive by the Feshbach resonance technique.
The subsequent dynamics is studied by solving the time-dependent mean-field
model including three-body loss due to molecule formation in boson-fermion and
boson-boson channels. Collapse and fragmentation in the fermions after
subsequent explosions are illustrated. The anisotropic dipolar interaction
leads to anisotropic fermionic density distribution during collapse. The
present study is carried out in three-dimensional space using realistic values
of dipolar and contact interactions.


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

abstract:
  In this report we summarize the many dark matter searches currently being
pursued through four complementary approaches: direct detection, indirect
detection, collider experiments, and astrophysical probes. The essential
features of broad classes of experiments are described, each with their own
strengths and weaknesses. The complementarity of the different dark matter
searches is discussed qualitatively and illustrated quantitatively in two
simple theoretical frameworks. Our primary conclusion is that the diversity of
possible dark matter candidates requires a balanced program drawing from all
four approaches.

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


title:
Full mass range analysis of the QED effective action for an O(2)xO(3)
  symmetric field

abstract:
  An interesting class of background field configurations in quantum
electrodynamics (QED) are the O(2)xO(3) symmetric fields, originally introduced
by S.L. Adler in 1972. Those backgrounds have some instanton-like properties
and yield a one-loop effective action that is highly nontrivial, but amenable
to numerical calculation. Here, we use the recently developed
"partial-wave-cutoff method" for a full mass range numerical analysis of the
effective action for the "standard" O(2)xO(3) symmetric field, modified by a
radial suppression factor. At large mass, we are able to match the asymptotics
of the physically renormalized effective action against the leading two mass
levels of the inverse mass expansion. For small masses, with a suitable choice
of the renormalization scheme we obtain stable numerical results even in the
massless limit. We analyze the N - point functions in this background and show
that, even in the absence of the radial suppression factor, the two-point
contribution to the effective action is the only obstacle to taking its
massless limit. The standard O(2)xO(3) background leads to a chiral anomaly
term in the effective action, and both our perturbative and nonperturbative
results strongly suggest that the small-mass asymptotic behavior of the
effective action is, after the subtraction of the two-point contribution,
dominated by this anomaly term as the only source of a logarithmic mass
dependence. This confirms a conjecture by M. Fry.


title:
Asteroid family identification using the Hierarchical Clustering Method
  and WISE/NEOWISE physical properties

abstract:
  Using albedos from WISE/NEOWISE to separate distinct albedo groups within the
Main Belt asteroids, we apply the Hierarchical Clustering Method to these
subpopulations and identify dynamically associated clusters of asteroids. While
this survey is limited to the ~35% of known Main Belt asteroids that were
detected by NEOWISE, we present the families linked from these objects as
higher confidence associations than can be obtained from dynamical linking
alone. We find that over one-third of the observed population of the Main Belt
is represented in the high-confidence cores of dynamical families. The albedo
distribution of family members differs significantly from the albedo
distribution of background objects in the same region of the Main Belt, however
interpretation of this effect is complicated by the incomplete identification
of lower-confidence family members. In total we link 38,298 asteroids into 76
distinct families. This work represents a critical step necessary to debias the
albedo and size distributions of asteroids in the Main Belt and understand the
formation and history of small bodies in our Solar system.


title:
Magnetic proximity effect in the 3D topological insulator/ferromagnetic
  insulator heterostructure

abstract:
  We theoretically study the magnetic proximity effect in the three dimensional
(3D) topological insulator/ferromagnetic insulator (TI/FMI) structures in the
context of possibility to manage the Dirac helical state in TI. Within
continual approach based on the $\mathbf{kp}$ Hamiltonian we predict that, when
3D TI is brought into contact with 3D FMI, the ordinary bound state arising at
the TI/FMI interface becomes spin polarized due to the orbital mixing at the
boundary. Whereas the wave function of FMI decays into the TI bulk on the
atomic scale, the induced exchange field, which is proportional to the FMI
magnetization, builds up at the scale of the penetration depth of the ordinary
interface state. Such the exchange field opens the gap at the Dirac point in
the energy spectrum of the topological bound state existing on the TI side of
the interface. We estimate the dependence of the gap size on the material
parameters of the TI/FMI contact.


title:
Formal Representation of the SS-DB Benchmark and Experimental Evaluation
  in EXTASCID

abstract:
  Evaluating the performance of scientific data processing systems is a
difficult task considering the plethora of application-specific solutions
available in this landscape and the lack of a generally-accepted benchmark. The
dual structure of scientific data coupled with the complex nature of processing
complicate the evaluation procedure further. SS-DB is the first attempt to
define a general benchmark for complex scientific processing over raw and
derived data. It fails to draw sufficient attention though because of the
ambiguous plain language specification and the extraordinary SciDB results. In
this paper, we remedy the shortcomings of the original SS-DB specification by
providing a formal representation in terms of ArrayQL algebra operators and
ArrayQL/SciQL constructs. These are the first formal representations of the
SS-DB benchmark. Starting from the formal representation, we give a reference
implementation and present benchmark results in EXTASCID, a novel system for
scientific data processing. EXTASCID is complete in providing native support
both for array and relational data and extensible in executing any user code
inside the system by the means of a configurable metaoperator. These features
result in an order of magnitude improvement over SciDB at data loading,
extracting derived data, and operations over derived data.


title: Positive linear functionals on BP*-algebras

abstract:
  Let A be a BP*-algebra with identity e, P_{1}(A) be the set of all positive
linear functionals f on A such that f(e) = 1, and let M_{s}(A) be the set of
all nonzero hermitian multiplicative linear functionals on A. We prove that
M_{s}(A) is the set of extreme points of P_{1}(A). We also prove that, if
M_{s}(A) is equicontinuous, then every positive linear functional on A is
continuous. Finally, we give an example of a BP*-algebra whose topological dual
is not included in the vector space generated by P_{1}(A), which gives a
negative answer to a question posed by M. A. Hennings.


title: Matrix element analyses of dark matter scattering and annihilation

abstract:
  We provide a compendium of results at the level of matrix elements for a
systematic study of dark matter scattering and annihilation. We identify
interactions that yield spin-dependent and spin-independent scattering and
specify whether the interactions are velocity- and/or momentum-suppressed. We
identify the interactions that lead to s-wave or p-wave annihilation, and those
that are chirality-suppressed. We also list the interaction structures that can
interfere in scattering and annihilation processes. Using these results, we
point out situations in which deviations from the standard lore are obtained.


title:
Bulk Fermi surface and electronic properties of
  Cu$_{0.07}$Bi$_{2}$Se$_{3}$

abstract:
  The electronic properties of Cu$_{0.07}$Bi$_{2}$Se$_{3}$ have been
investigated using Shubnikov-de Haas and optical reflectance measurements.
Quantum oscillations reveal a bulk, three-dimensional Fermi surface with
anisotropy $k^{c}_{F}/k^{ab}_{F}\approx$ 2 and a modest increase in
free-carrier concentration and in scattering rate with respect to the undoped
Bi$_{2}$Se$_{3}$, also confirmed by reflectivity data. The effective mass is
almost identical to that of Bi$_{2}$Se$_{3}$. Optical conductivity reveals a
strong enhancement of the bound impurity bands with Cu addition, suggesting
that a significant number of Cu atoms enter the interstitial sites between Bi
and Se layers or may even substitute for Bi. This conclusion is also supported
by X-ray diffraction measurements, where a significant increase of microstrain
was found in Cu$_{0.07}$Bi$_{2}$Se$_{3}$, compared to Bi$_{2}$Se$_{3}$.


title: Homological shadows of attracting laminations

abstract:
  Given a free group $F_n$, a fully irreducible automorphism $f \in \aut$, and
a generic element $x \in F_n$, the elements $f^k(x)$ converge in the
appropriate sense to an object called an attracting lamination of $f$. When the
action of $f$ on $\frac{F_n}{[F_n, F_n]}$ has finite order, we introduce a
homological version of this convergence, in which the attracting object is a
convex polytope with rational vertices, together with a measure supported at a
point with algebraic coordinates.


title: The topology of rationally and polynomially convex domains

abstract:
  We give in this article necessary and sufficient conditions on the topology
of rationally and polynomially convex domains.


title: Each instant of time a new Universe

abstract:
  We present an alternative view of quantum evolution in which each moment of
time is viewed as a new "universe" and time evolution is given by correlations
between them.


title: Local control of single atom magneto-crystalline anisotropy

abstract:
  Individual Fe atoms on a Cu2N/Cu(100) surface exhibit strong magnetic
anisotropy due to the crystal field. Using atom manipulation in a
low-temperature STM we demonstrate that the anisotropy of one Fe atom is
significantly influenced by local strain due to a second Fe atom placed nearby.
Depending on the relative positions of the two atoms on the Cu2N lattice we can
controllably enhance or reduce the uniaxial anisotropy. We present a model that
explains the observed behavior qualitatively in terms of first principles.


title: Motivic Amplitudes and Cluster Coordinates

abstract:
  In this paper we study motivic amplitudes--objects which contain all of the
essential mathematical content of scattering amplitudes in planar SYM theory in
a completely canonical way, free from the ambiguities inherent in any attempt
to choose particular functional representatives. We find that the cluster
structure on the kinematic configuration space Conf_n(P^3) underlies the
structure of motivic amplitudes. Specifically, we compute explicitly the
coproduct of the two-loop seven-particle MHV motivic amplitude A_{7,2} and find
that like the previously known six-particle amplitude, it depends only on
certain preferred coordinates known in the mathematics literature as cluster
X-coordinates on Conf_n(P^3). We also find intriguing relations between motivic
amplitudes and the geometry of generalized associahedrons, to which cluster
coordinates have a natural combinatoric connection. For example, the
obstruction to A_{7,2} being expressible in terms of classical polylogarithms
is most naturally represented by certain quadrilateral faces of the appropriate
associahedron. We also find and prove the first known functional equation for
the trilogarithm in which all 40 arguments are cluster X-coordinates of a
single algebra. In this respect it is similar to Abel's 5-term dilogarithm
identity.


title: Localization of Matrix Factorizations

abstract:
  Matrices with off-diagonal decay appear in a variety of fields in mathematics
and in numerous applications, such as signal processing, statistics,
communications engineering, condensed matter physics, and quantum chemistry.
Numerical algorithms dealing with such matrices often take advantage
(implicitly or explicitly) of the empirical observation that this off-diagonal
decay property seems to be preserved when computing various useful matrix
factorizations, such as the Cholesky factorization or the QR-factorization.
There is a fairly extensive theory describing when the inverse of a matrix
inherits the localization properties of the original matrix. Yet, except for
the special case of band matrices, surprisingly very little theory exists that
would establish similar results for matrix factorizations. We will derive a
comprehensive framework to rigorously answer the question when and under which
conditions the matrix factors inherit the localization of the original matrix
for such fundamental matrix factorizations as the LU-, QR-, Cholesky, and Polar
factorization.


title: Stein structures: existence and flexibility

abstract:
  This survey on the topology of Stein manifolds is an extract from our recent
joint book. It is compiled from two short lecture series given by the first
author in 2012 at the Institute for Advanced Study, Princeton, and the Alfred
Renyi Institute of Mathematics, Budapest.


title: The MASTER-II Network of Robotic Optical Telescopes. First Results

abstract: Erroneous submission in violation of copyright, removed by arXiv admin.


title: Location sharing without the central server

abstract:
  This paper describes a new model for sharing location info for mobile users.
This approach can operate without the need for disclosing identity info to
third party servers. It could be described as a safe location sharing model.
The proposed approach creates a special form of distributed database that
splits location info and identity information. In this distributed data store
identity info is always saved locally. It eliminates one of the main concerns
with location-based systems - privacy. This paper describes a model itself as
well as its implementation in the form of HTML5 mobile web application.


title:
Core collapse and horizontal-branch morphology in galactic globular
  clusters

abstract:
  Context. Stellar collision rates in globular clusters (GCs) do not appear to
correlate with horizontal branch (HB) morphology, sug- gesting that dynamics
does not play a role in the second-parameter problem. However, core densities
and collision rates derived from surface-brightness may be significantly
underestimated as the surface-brightness profile of GCs is not necessarily a
good indicator of the dynamical state of GC cores. Core-collapse may go
unnoticed if high central densities of dark remnants are present. Aims. We test
whether GC HB morphology data supports a dynamical contribution to the
so-called second-parameter effect. Methods. To remove first-parameter
dependence we fitted the maximum effective temperature along the HB as a
function of metal- licity in a sample of 54 Milky Way GCs. We plotted the
residuals to the fit as a function of second-parameter candidates, namely
dynamical age and total luminosity. We considered dynamical age (i.e. the ratio
between age and half-light relaxation time) among possible second-parameters.
We used a set of direct N-body simulations, including ones with dark remnants
to illustrate how core density peaks, due to core collapse, in a dynamical-age
range similar to that in which blue HBs are overabundant with respect to the
metallicity expectation, especially for low-concentration initial conditions.
Results. GC total luminosity shows nonlinear behavior compatible with the
self-enrichment picture. However, the data are amenable to a different
interpretation based on a dynamical origin of the second-parameter effect.
Enhanced mass-stripping in the late red-giant- branch phase due to stellar
interactions in collapsing cores is a viable candidate mechanism. In this
picture, GCs with HBs bluer than expected based on metallicity are those
undergoing core-collapse.


title: WZ production in association with two jets at NLO in QCD

abstract:
  We report on the calculation of $W^\pm Zjj$ production with leptonic decays
at hadron-hadron colliders at next-to-leading order in QCD. These processes are
important both to test the quartic gauge couplings of the Standard Model and
because they constitute relevant backgrounds to beyond standard model physics
searches. Our results show that the next-to-leading order corrections reduce
significantly the scale uncertainties and have a non-trivial phase space
dependence.


title: Heavy Higgs Searches and Constraints on Two Higgs Doublet Models

abstract:
  Since the discovery of a Higgs boson at the LHC and the measurement of many
of its branching ratios, there have been numerous studies exploring the
restrictions these results place on the parameter space of two Higgs doublet
models. We extend these results to include the full data set and study the
expected sensitivity that can be obtained with 300 and 3000 inverse femptobarn
of integrated luminosity. We consider searches for a heavy Standard Model Higgs
boson, with a mass ranging from 200 to 400 GeV, and show that the
non-observation of such a Higgs boson can substantially narrow the allowed
regions of parameter space in two Higgs doublet models.


title: On the origin of the B-stars in the Galactic center

abstract:
  We present a new directly-observable statistic which uses sky position and
proper motion of stars near the Galactic center massive black hole to identify
populations with high orbital eccentricities. It is most useful for stars with
large orbital periods for which dynamical accelerations are difficult to
determine. We apply this statistic to a data set of B-stars with projected
radii 0."1 < p < 25" (~0.004 - 1 pc) from the massive black hole in the
Galactic center. We compare the results with those from N-body simulations to
distinguish between scenarios for their formation. We find that the scenarios
favored by the data correlate strongly with particular K-magnitude intervals,
corresponding to different zero-age main-sequence (MS) masses and lifetimes.
Stars with 14 < mK < 15 (15 - 20 solar masses, t_{MS} = 8-13 Myr) match well to
a disk formation origin, while those with mK > 15 (<15 solar masses, t_{MS} >13
Myr), if isotropically distributed, form a population that is more eccentric
than thermal, which suggests a Hills binary-disruption origin.


title:
Angular Momentum and Galaxy Formation Revisited: Effects of Variable
  Mass-to-light Ratios

abstract:
  We rederive the relation between the specific angular momentum j_* and the
mass M_* of the stellar matter in galaxies of different morphological types.
This is a revision of the j_*--M_* diagram presented in our recent
comprehensive study of galactic angular momentum. In that work, we estimated
j_* from kinematic and photometric data that extended to large radii and M_*
from near-infrared luminosities L_K with an assumed universal mass-to-light
ratio M_*/L_K. However, recent stellar population models show large variations
in M_*/L_K correlated with B-V color. In the present work, we use this
correlation to estimate M_*/L_K and hence M_* from the measured B-V and L_K.
Our revised j_*--M_* diagram is similar to our previous one; both
disk-dominated and elliptical galaxies follow nearly parallel sequences with
j_* \propto M_*^\alpha\ and \alpha = 0.6 +/- 0.1. However, the offset between
the sequences is now a factor of about 5, some 30% larger than before (and
close to the offset found by Fall in 1983). Thus, our new results place even
tighter constraints on the loss of specific angular momentum by galactic disks
over their lifetimes.


title: Spontaneous breaking of the flavor symmetry avoids the strong CP problem

abstract:
  A promising approach to the Standard Model flavor puzzle is based on the idea
that the $SU(3)^3$ quark-flavor symmetry is spontaneously broken by vacuum
expectation values of `Yukawa fields' which minimize the symmetry invariant
scalar potential at configurations corresponding to the observed quark masses
and mixing angles. We show that this approach provides a simple and elegant
explanation for CP conservation in strong interactions.


title:
Searching for nuclear stellar discs in simulations of star cluster
  mergers

abstract:
  The nuclei of galaxies often host small stellar discs with scale-lengths of a
few tens of parsecs and luminosities up to 10^7 Lsun. To investigate the
formation and properties of nuclear stellar discs (NSDs), we look for their
presence in a set of N-body simulations studying the dissipationless merging of
multiple star clusters in galactic nuclei. A few tens of star clusters with
sizes and masses comparable to those of globular clusters observed in the Milky
Way are accreted onto a pre-existing nuclear stellar component: either a
massive super star cluster or a rapidly rotating, compact disc with a
scale-length of a few parsecs, mimicing the variety of observed nuclear
structures. Images and kinematic maps of the simulation time-steps are then
built and analysed as if they were real and at the distance of the Virgo
cluster. We use the Scorza-Bender method to search for the presence of disc
structures via photometric decomposition. In one case the merger remnant has
all the observed photometric and kinematic properties of NSDs observed in real
galaxies. This shows that current observations are consistent with most of the
NSD mass being assembled from the migration and accretion of star clusters into
the galactic centre. In the other simulation instead, we detect an elongated
structure from the unsharp masked image, that does not develop the photometric
or kinematic signature of a NSD. Thus, in the context of searches for a disc
structure, the Scorza-Bender method is a robust and necessary tool.


title:
Ringing the initial Universe: the response of overdensity and
  transformed-density power spectra to initial spikes

abstract:
  We present an experiment in which we 'ring' a set of cosmological
N-body-simulation initial conditions, placing spikes in the initial power
spectrum at different wavenumber bins. We then measure where these spikes end
up in the final conditions. In the usual overdensity power spectrum, most
sensitive to contracting and collapsing dense regions, initial power on
slightly non-linear scales (k ~ 0.3 h/Mpc) smears to smaller scales, coming to
dominate the initial power once there. Log-density and Gaussianized-density
power spectra, sensitive to low-density (expanding) and high-density regions,
respond differently: initial spikes spread symmetrically in scale, both upward
and downward. In fact, in the power spectrum of 1/(1 + {\delta}), spikes
migrate to larger scales, showing the magnifying effect of voids on small-scale
modes. These power spectra show much greater sensitivity to small-scale initial
features. We also test the difference between an approximation of the
Ly-{\alpha} flux field, and its Gaussianized form, and give a toy model that
qualitatively explains the symmetric power spreading in Gaussianized-density
power spectra. Also, we discuss how to use this framework to estimate
power-spectrum covariance matrices. This can be used to track the fate of
information in the Universe, that takes the form of initial degrees of freedom,
one random spike per initial mode.


title:
The Cosmic Star Formation Rate from the Faintest Galaxies in the
  Unobservable Universe

abstract:
  Observations of high-z galaxies and gamma-ray bursts now allow for empirical
studies during reionization. However, even deep surveys see only the brightest
galaxies at any epoch and must extrapolate to arbitrary lower limits to
estimate the total rate of star formation. We first argue that the galaxy
populations seen in LBG surveys yield a GRB rate at z > 8 that is an order of
magnitude lower than observed. We find that integrating the inferred UV
luminosity functions down to M_UV ~ -10 brings LBG- and GRB-inferred SFR
density values into agreement up to z ~ 8. GRBs, however, favor a far larger
amount of as yet unseen star formation at z > 9. We suggest that the SFR
density may only slowly decline out to z ~ 11, in accord with WMAP and Planck
reionization results, and that GRBs may be useful in measuring the scale of
this multitude of dwarf galaxies.


title: Discrete clouds of neutral gas between the galaxies M31 and M33

abstract:
  Spiral galaxies must acquire gas to maintain their observed level of star
formation beyond the next few billion years (Leroy et al. 2008). A source of
this material may be the gas that resides between galaxies, but our
understanding of the state and distribution of this gas is incomplete (Shull et
al. 2012). Radio observations (Braun & Thilker 2004) of the Local Group of
galaxies have revealed hydrogen gas extending from the disk of the galaxy M31
at least halfway to M33. This feature has been interpreted to be the neutral
component of a condensing intergalactic filament (Dav\'e et al. 2001) which
would be able to fuel star formation in M31 and M33, but simulations suggest
that such a feature could also result from an interaction between both galaxies
within the past few billion years (Bekki 2008). Here we report radio
observations showing that about 50 per cent percent of this gas is composed of
clouds, while the rest is distributed in an extended, diffuse component. The
clouds have velocities comparable to those of M31 and M33, and have properties
suggesting they are unrelated to other Local Group objects. We conclude that
the clouds are likely to be transient condensations of gas embedded in an
intergalactic filament and are therefore a potential source of fuel for future
star formation in M31 and M33.


title: Non-perturbative Massive Solutions in Gravitational Higgs Mechanism

abstract:
  We construct exact non-perturbative massive solutions in the gravitational
Higgs mechanism. They confirm the conclusions of arXiv:1102.4991, which are
based on non-perturbative Hamiltonian analysis for the relevant metric degrees
of freedom, that while perturbatively unitarity may not be evident, no negative
norm state is present in the full nonlinear theory. The non-perturbative
massive solutions do not appear to exhibit instabilities and describe vacuum
configurations which are periodic in time, including purely longitudinal
solutions with isotropic periodically expanding and contracting spatial
dimensions, "cosmological strings" with only one periodically expanding and
contracting spatial dimension, and also purely non-longitudinal ("traceless")
periodically expanding and contracting solutions with constant spatial volume.
As an aside we also discuss massive solutions in New Massive Gravity. While
such solutions are present in the linearized theory, we argue that already at
the next-to-linear (quadratic) order in the equations of motion (and, more
generally, for weak-field configurations) there are no massive solutions.


title: Aspects of 3d N=2 Chern-Simons-Matter Theories

abstract:
  We comment on various aspects of the the dynamics of 3d N=2 Chern-Simons
gauge theories and their possible phases. Depending on the matter content, real
masses and FI parameters, there can be non-compact Higgs or Coulomb branches,
compact Higgs or Coulomb branches, and isolated vacua. We compute the Witten
index of the theories, and show that it does not change when the system
undergoes a phase transition. We study aspects of monopole operators and
solitons in these theories, and clarify subtleties in the soliton collective
coordinate quantization. We show that solitons are compatible with a mirror
symmetry exchange of Higgs and Coulomb branches, with BPS solitons on one
branch related to the modulus of the other. Among other results, we show how to
derive Aharony duality from Giveon-Kutasov duality.


title: Impact of network topology on synchrony of oscillatory power grids

abstract:
  Replacing conventional power sources by renewable sources in current power
grids drastically alters their structure and functionality. The resulting grid
will be far more decentralized with an distinctly different topology. Here we
analyze the impact of grid topologies on spontaneous synchronization,
considering regular, random and small-world topologies and focusing on the
influence of decentralization. We employ the classic model of power grids
modeling consumers and sources as second order oscillators. We first analyze
the global dynamics of the simplest non-trivial (two-node) network that exhibit
a synchronous (normal operation) state, a limit cycle (power outage) and
coexistence of both. Second, we estimate stability thresholds for the
collective dynamics of small network motifs, in particular star-like networks
and regular grid motifs. For larger networks we numerically investigate
decentralization scenarios finding that decentralization itself may support
power grids in reaching stable synchrony for lower lines transmission
capacities. Decentralization may thus be beneficial for power grids, regardless
of their special resulting topology. Regular grids exhibit a specific
transition behavior not found for random or small-world grids.


title: Flexible Weinstein manifolds

abstract:
  This survey on flexible Weinstein manifolds is, essentially, an extract from
our recent joint book.


title: Global holomorphic functions in several non-commuting variables

abstract:
  We define a free holomorphic function to be a function that is locally a
bounded nc-function. We prove that free holomorphic functions are the functions
that are locally uniformly approximable by free polynomials. We prove a
realization formula and an Oka-Weil theorem for free analytic functions.


title: Torsors and the Quillen-Barr-Beck cohomology for restricted Lie algebras

abstract:
  Given an exact sequence of restricted Lie algebras using Duskin's torsors
theory, we establish an eight term exact sequence for Quillen-Barr-Beck
cohomology of restricted Lie algebras. As an application we obtain for any
extension of algebraic groups over an algebraic closed field of prime
characteristic an eight term exact sequence for the corresponding restricted
Lie algebras extension.


title:
Some homotopy theoretical questions arising in Nielsen coincidence
  theory

abstract:
  Basic examples show that coincidence theory is intimately related to central
subjects of differential topology and homotopy theory such as Kervaire
invariants and divisibility properties of Whitehead products and of Hopf
invariants. We recall some recent results and ask a few questions which seems
to be important for a more comprehensive understanding.


title:
Parity of the number of primes in a given interval and algorithms of the
  sublinear summation

abstract:
  Recently Tao, Croot and Helfgott invented an algorithm to determine the
parity of the number of primes in a given interval in O(x^{1/2-c+\eps}) steps
for some absolute constant c. We propose a slightly different approach, which
leads to the implicit value of c. To achieve this aim we discuss the summation
of multiplicative functions, developing sublinear algorithms and proving
several general theorems.


title:
Quintom potentials from quantum cosmology using the FRW cosmological
  model

abstract:
  We construct the quintom potential of dark energy models in the framework of
spatially flat Friedmann-Robertson Walker universe in the inflationary epoch,
using the Bohm like approach, known as amplitude-real-phase. We find some
potentials for which the wave function of the universe is found analytically
and we have obtained the classical trajectories in the inflation era.


title: Micromagnetic modelling of anisotropic damping in ferromagnet

abstract:
  We report a numerical implementation of the Landau-Lifshitz-Baryakhtar
theory, which dictates that the micromagnetic relaxation term obeys the
symmetry of the magnetic crystal, i. e. replacing the single intrinsic damping
constant with a tensor of corresponding symmetry. The effect of anisotropic
relaxation is studied in thin saturated ferromagnetic disk and ellipse with and
without uniaxial magneto-crystalline anisotropy. We investigate the angular
dependency of the linewidth of magnonic resonances with respect to the given
structure of the relaxation tensor. The simulations suggest that the anisotropy
of the magnonic linewidth is determined by only two factors: the projection of
the relaxation tensor onto the plane of precession and the ellipticity of the
later.


title: Positive half of the Witt algebra acts on triply graded link homology

abstract:
  The positive half of the Witt algebra is the Lie algebra spanned by vector
fields x^{m+1} d/dx acting as differentiations on the polynomial algebra Q[x]
upon which the Soergel bimodule construction of triply graded link homology is
based. We show that this action of Witt algebra can be extended to the link
homology.


title:
Ground-based detections of thermal emission from the dense hot Jupiter
  WASP-43b in H and Ks-bands

abstract:
  We report new detections of thermal emission from the transiting hot Jupiter
WASP-43b in the H and Ks-bands as observed at secondary eclipses. The
observations were made with the WIRCam instrument on the CFHT. We obtained a
secondary eclipse depth of 0.103$_{-0.017}^{+0.017}%$ and
0.194$_{-0.029}^{+0.029}%$ in the H and Ks-bands, respectively. The Ks band
depth is consistent with previous measurement in the narrow band centered at
2.09um by Gillon et al. (2012). Our eclipse depths in both bands are consistent
with a blackbody spectrum with a temperature of ~1850 K, slightly higher than
the dayside equilibrium temperature without day-night energy redistribution.
Based on theoretical models of the dayside atmosphere of WASP-43b, our data
constrain the day-night energy redistribution in the planet to be $\lesssim
15-25$%, depending on the metal content in the atmosphere. Combined with energy
balance arguments our data suggest that a strong temperature inversion is
unlikely in the dayside atmosphere of WASP-43b. However, a weak inversion
cannot be strictly ruled out at the current time. Future observations are
required to place detailed constraints on the chemical composition of the
atmosphere.


title:
Radio polarimetry of compact steep spectrum sources at sub-arcsecond
  resolution

abstract:
  Aims - We report new Very Large Array polarimetric observations of Compact
Steep-Spectrum (CSS) sources at 8.4, 15, and 23GHz. Methods - Using
multi-frequency VLA observations we have derived sub-arcsecond resolution
images of the total intensity, polarisation, and rotation measure (RM)
distributions. Results heading - We present multi-frequency VLA polarisation
observations of CSS sources. About half of the sources are point-like even at
the resolution of about 0.1x0.1 arcseconds. The remaining sources have double
or triple structure. Low values for the percentage of polarised emission in CSS
sources is confirmed. On the average, quasars are more polarised than galaxies.
A wide range of RM values have been measured. There are clear indications of
very large RMs up to 5\,585 rad m**(-2). CSS galaxies are characterized by RM
values that are larger than CSS quasars. The majority of the objects show very
large values of RM. Conclusions - The available data on sub-arcsecond-scale
rest-frame RM estimates for CSS sources show that these have a wide range of
values extending up to about 36,000 rad m**(-2). RM estimates indicate an
overall density of the magneto-ionic medium larger than classical radio
sources.


title: QCD resummation in the framework of supersymmetry

abstract:
  Motivated by current searches for electroweak superpartners at the Large
Hadron Collider, we present precision predictions for pair production of such
particles in the framework of the Minimal Supersymmetric Standard Model. We
make use of various QCD resummation formalisms and match the results to pure
perturbative QCD computations. We study the impact of scale variations and
compare our results to predictions obtained by means of traditionally used
Monte Carlo event generators.


title: F-singularities in families

abstract:
  We study the behavior of test ideals and F-singularities in families. In
particular, we obtain generic (and non-generic) restriction theorems for test
ideals and non-F-pure ideals. Additionally, we study the global behavior of
certain canonical linear systems (induced by Frobenius) associated to adjoint
line bundles, in families. As a consequence, we obtain some positivity results
for pushforwards of some adjoint line bundles and for certain subsheaves of
these.


title:
Dust and star-formation properties of a complete sample of local
  galaxies drawn from the Planck Early Release Compact Source Catalogue

abstract:
  We combine Planck HFI data at 857, 545, 353 & 217GHz with data from WISE,
Spitzer, IRAS & Herschel to investigate the properties of a flux limited sample
of local star-forming galaxies. A 545GHz flux density limit was chosen so that
the sample is 80% complete at this frequency, giving a sample of 234 local
galaxies. We investigate the dust emission and star formation properties of the
sample via various models & calculate the local dust mass function. Although
1-component modified black bodies fit the dust emission longward of 80um very
well (median beta=1.83) the degeneracy between dust temp & beta also means that
the SEDs are very well described by a dust emissivity index fixed at beta=2 and
10<T<25 K. Although a second, warmer dust component is required to fit shorter
wavelength data, & contributes ~1/3 of the total infrared emission, its mass is
negligible. No evidence is found for a very cold (6-10 K) dust component. The
temp of the cold dust component is strongly influenced by the ratio of the star
formation rate to the total dust mass. This implies, contrary to what is often
assumed, that a significant fraction of even the emission from ~20 K dust is
powered by ongoing star formation, whether or not the dust itself is associated
with star forming clouds or `cirrus'. There is statistical evidence of a
free-free contribution to the 217GHz flux densities of <20%. We find a median
dust-to-stellar mass ratio of 0.0046; & that this ratio is anti-correlated with
galaxy mass. There is good correlation between dust mass & atomic gas mass
(median M_d/M_HI = 0.022), suggesting that galaxies that have more dust have
more interstellar medium in general. Our derived dust mass function implies a
mean dust mass density of the local Universe (for dust within galaxies), of
7.0+-1.4 x 10^5 M_solar/Mpc, significantly greater than that found in the most
recent estimate using Herschel data.


title: Global risk bounds and adaptation in univariate convex regression

abstract:
  We consider the problem of nonparametric estimation of a convex regression
function $\phi_0$. We study the risk of the least squares estimator (LSE) under
the natural squared error loss. We show that the risk is always bounded from
above by $n^{-4/5}$ modulo logarithmic factors while being much smaller when
$\phi_0$ is well-approximable by a piecewise affine convex function with not
too many affine pieces (in which case, the risk is at most $1/n$ up to
logarithmic factors). On the other hand, when $\phi_0$ has curvature, we show
that no estimator can have risk smaller than a constant multiple of $n^{-4/5}$
in a very strong sense by proving a "local" minimax lower bound. We also study
the case of model misspecification where we show that the LSE exhibits the same
global behavior provided the loss is measured from the closest convex
projection of the true regression function. In the process of deriving our risk
bounds, we prove new results for the metric entropy of local neighborhoods of
the space of univariate convex functions. These results, which may be of
independent interest, demonstrate the non-uniform nature of the space of
univariate convex functions in sharp contrast to classical function spaces
based on smoothness constraints.


title: Status of the two-Higgs-doublet model of type II

abstract:
  We determine the allowed parameter space of the CP-conserving
two-Higgs-doublet model (2HDM) of type II with a softly broken Z_2 symmetry.
Our analysis includes theoretical constraints from vacuum stability and
perturbativity as well as experimental constraints from signal strengths of the
126 GeV Higgs boson, the non-observation of additional Higgs resonances and
electroweak precision and flavour observables. If the 126 GeV resonance is
interpreted as the light CP-even Higgs boson of the 2HDM our analysis shows
that scenarios where the couplings of this boson deviate substantially from
those of the SM Higgs boson are disfavoured at one standard deviation and
completely excluded for small values of tan(beta). We also discuss bounds on
the masses of the heavy 2HDM Higgs bosons and their implications for the
possible decay modes of these particles. We find that the region in which both
non-standard neutral Higgs bosons are simultaneously lighter than 300 GeV is
excluded at two standard deviations.


title:
Nielsen coincidence theory of fibre-preserving maps and Dold's fixed
  point index

abstract:
  Let M to B, N to B be fibrations and f1,f2 :M to N be a pair of
fibre-preserving maps. Using normal bordism techniques we define an invariant
which is an obstruction to deforming the pair f1,f2 over B to a coincidence
free pair of maps.In the special case where the two fibrations are the same and
one of the maps is the identity, a weak version of our {\omega}-invariant turns
out to equal Dold's fixed point index of fibre-preserving maps. The concepts of
Reidemeister classes and Nielsen coincidence classes over B are developed. As
an illustration we compute e.g. the minimal number of coincidence components
for all homotopy classes of maps between S^1-bundles over S^1 as well as their
Nielsen and Reidemeister numbers.


title: On the resolution of path ideals of cycles

abstract:
  We give a formula to compute all the top degree graded Betti numbers of the
path ideal of a cycle. Also we will find a criterion to determine when Betti
numbers of this ideal are non zero and give a formula to compute its projective
dimension and regularity.


title:
Study of cylindrically symmetric solutions in metric f(R) gravity with
  constant R

abstract:
  Solutions for cylindrically symmetric spacetimes in f(R) gravity are studied.
As a first approach, R=constant is assumed. A solution was found such that it
is equivalent to a result given by Azadi et al. for R=0 and a metric was found
for R=constant different from zero. Comparison with the case of general
relativity with cosmological constant is made and the metric constants are
given in terms of \Lambda. Overlap with arXiv:0810.4673 [gr-qc] by A. Azadi, D.
Momeni and M. Nouri-Zonoz


title: Comparison Techniques for Competing Brownian Particles

abstract:
  Consider a finite system of Brownian particles on the real line. Each
particle has drift and diffusion coefficients depending on its current rank
relative to other particles, as in Karatzas, Pal and Shkolnikov (2012). We
prove some comparison results for these systems. As an example, we show that if
we remove a few particles from the top, then the gaps between adjacent
particles become stochastically larger, the local times of collision between
adjacent particles become stochastically smaller, and the remaining particles
shift upward, in the sense of stochastic ordering.


title: Reidemeister coincidence invariants of fiberwise maps

abstract:
  Given two fiberwise maps f1, f2 between smooth fiber bundles over a base
manifold B, we develop techniques for calculating their Nielsen coincidence
number. In certain settings we can describe the Reidemeister set of (f1,f2) as
the orbit set of a group operation of {\pi}1(B). The size and number of orbits
captures crucial extra information. E.g. for torus bundles of arbitrary
dimensions over the circle this determines the minimum coincidence numbers of
the pair (f1,f2) completely. In particular we can decide when f1 and f2 can be
deformed away from one another or when a fiberwise selfmap can be made fixed
point free by a suitable homotopy. In two concrete examples we calculate the
minimum and Nielsen numbers for all pairs of fiberwise maps explicitly. Odd
order orbits turn out to play a special role.


title:
A short note on estimating intelligence from user profiles in the
  context of universal psychometrics: prospects and caveats

abstract:
  There has been an increasing interest in inferring some personality traits
from users and players in social networks and games, respectively. This goes
beyond classical sentiment analysis, and also much further than customer
profiling. The purpose here is to have a characterisation of users in terms of
personality traits, such as openness, conscientiousness, extraversion,
agreeableness, and neuroticism. While this is an incipient area of research, we
ask the question of whether cognitive abilities, and intelligence in
particular, are also measurable from user profiles. However, we pose the
question as broadly as possible in terms of subjects, in the context of
universal psychometrics, including humans, machines and hybrids. Namely, in
this paper we analyse the following question: is it possible to measure the
intelligence of humans and (non-human) bots in a social network or a game just
from their user profiles, i.e., by observation, without the use of interactive
tests, such as IQ tests, the Turing test or other more principled machine
intelligence tests?


title: Markov counting models for correlated binary responses

abstract:
  We propose a class of continuous-time Markov counting processes for analyzing
correlated binary data and establish a correspondence between these models and
sums of exchangeable Bernoulli random variables. Our approach generalizes many
previous models for correlated outcomes, admits easily interpretable
parameterizations, allows different cluster sizes, and incorporates
ascertainment bias in a natural way. We demonstrate several new models for
dependent outcomes and provide algorithms for computing maximum likelihood
estimates. We show how to incorporate cluster-specific covariates in a
regression setting and demonstrate improved fits to well-known datasets from
familial disease epidemiology and developmental toxicology.


title:
Low Complexity Indoor Localization in Wireless Sensor Networks by UWB
  and Inertial Data Fusion

abstract:
  Precise indoor localization of moving targets is a challenging activity which
cannot be easily accomplished without combining different sources of
information. In this sense, the combination of different data sources with an
appropriate filter might improve both positioning and tracking performance.
This work proposes an algorithm for hybrid positioning in Wireless Sensor
Networks based on data fusion of UWB and inertial information. A constant-gain
Steady State Kalman Filter is used to bound the complexity of the system,
simplifying its implementation on a typical low-power WSN node. The performance
of the presented data fusion algorithm has been evaluated in a realistic
scenario using both simulations and realistic datasets. The obtained results
prove the validity of this approach, which efficiently fuses different
positioning data sources, reducing the localization error.


title:
Spectroscopic Constants and Vibrational Frequencies for l-C3H+ and
  Isotopologues from Highly-Accurate Quartic Force Fields: The Detection of
  l-C3H+ in the Horsehead Nebula PDR Questioned

abstract:
  Very recently, molecular rotational transitions observed in the
photon-dominated region of the Horsehead nebula have been attributed to l-C3H+.
In an effort to corroborate this finding, we employed state-of-the art and
proven high-accuracy quantum chemical techniques to compute spectroscopic
constants for this cation and its isotopologues. Even though the B rotational
constant from the fit of the observed spectrum and our computations agree to
within 20 MHz, a typical level of accuracy, the D rotational constant differs
by more than 40%, while the H rotational constant differs by three orders of
magnitude. With the likely errors in the rotational transition energies
resulting from this difference in D on the order of 1 MHz for the lowest
observed transition (J = 4 <- 3) and growing as J increases, the assignment of
the observed rotational lines from the Horsehead nebula to l-C3H+ is
questionable.


title:
Invariants of hypergeometric groups for Calabi-Yau complete
  intersections in weighted projective spaces

abstract:
  Let Y be a Calabi-Yau complete intersection in a weighted projective space.
We show that the space of quadratic invariants of the hypergeometric group
associated with the twisted I-function is one-dimensional, and spanned by the
Gram matrix of a split-generator of the derived category of coherent sheaves on
Y with respect to the Euler form.


title:
The Possible Interstellar Anion CH2CN-: Spectroscopic Constants,
  Vibrational Frequencies, and Other Considerations

abstract:
  It is hypothesized that the A ^1B_1 <- X ^1A' excitation into the
dipole-bound state of the cyanomethyl anion (CH2CN-) is proposed as the carrier
for one diffuse interstellar band. However, this particular molecular system
has not been detected in the interstellar medium even though the related
cyanomethyl radical and the isoelectronic ketenimine molecule have been found.
In this study we are employing the use of proven quartic force fields and
second-order vibrational perturbation theory to compute accurate spectroscopic
constants and fundamental vibrational frequencies for ^1A' CH2CN- in order to
assist in laboratory studies and astronomical observations.


title:
Scanning Gate Spectroscopy of transport across a Quantum Hall
  Nano-Island

abstract:
  We explore transport across an ultra-small Quantum Hall Island (QHI) formed
by closed quan- tum Hall edge states and connected to propagating edge channels
through tunnel barriers. Scanning gate microscopy and scanning gate
spectroscopy are used to first localize and then study a single QHI near a
quantum point contact. The presence of Coulomb diamonds in the spectroscopy
con- firms that Coulomb blockade governs transport across the QHI. Varying the
microscope tip bias as well as current bias across the device, we uncover the
QHI discrete energy spectrum arising from electronic confinement and we extract
estimates of the gradient of the confining potential and of the edge state
velocity.


title: Plutino Detection Biases, Including the Kozai Resonance

abstract:
  Because of their proximity within the transneptunian region, the plutinos
(objects in the 3:2 mean-motion resonance with Neptune) are numerous in
flux-limited catalogs, and well-studied theoretically. We perform detailed
modelling of the on-sky detection biases for plutinos, with special attention
to those that are simultaneously in the Kozai resonance. In addition to the
normal 3:2 resonant argument libration, Kozai plutinos also show periodic
oscillations in eccentricity and inclination, coupled to the argument of
perihelion (omega) oscillation. Due to the mean-motion resonance, plutinos
avoid coming to pericenter near Neptune's current position in the ecliptic
plane. Because Kozai plutinos are restricted to certain values of omega,
perihelion always occurs out of the ecliptic plane, biasing ecliptic surveys
against finding these objects. The observed Kozai plutino fraction (fkoz) has
been measured by several surveys, finding values between 8% and 25%, while the
true fkoz has been predicted to be between 10% and 30% by different giant
planet migration simulations. We show that the observed fkoz varies widely
depending on the ecliptic latitude and longitude of the survey, so debiasing to
find the true ratio is complex. Even a survey that covers most or all of the
sky will detect an apparent Kozai fraction that is different from the true
fkoz. We present a map of the on-sky plutino Kozai fraction that would be
detected by all-sky flux-limited surveys. This will be especially important for
the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) and Large
Synoptic Survey Telescope (LSST) projects, which may detect large numbers of
plutinos as they sweep the sky. The Kozai fraction and the distribution of the
orbital elements of Kozai plutinos may be a diagnostic of giant planet
migration; future migration simulations should provide details on their
resonant Kozai populations.


title:
Evolution of the Mass-Metallicity relations in passive and star-forming
  galaxies from SPH-cosmological simulations

abstract:
  We present results from SPH-cosmological simulations, including
self-consistent modelling of SN feedback and chemical evolution, of galaxies
belonging to two clusters and twelve groups. We reproduce the mass-metallicity
(ZM) relation of galaxies classified in two samples according to their
star-forming activity, as parametrized by their sSFR, across a redshift range
up to z=2.
  Its slope shows irrelevant evolution in the passive sample, being steeper in
groups than in clusters. However, the sub-sample of high-mass passive galaxies
only is characterized by a steep increase of the slope with redshift, from
which it can be inferred that the bulk of the slope evolution of the ZM
relation is driven by the more massive passive objects. (...ABRIDGED...)
  The ZM relation for the star-forming sample reveals an increasing scatter
with redshift, indicating that it is still being built at early epochs. The
star-forming galaxies make up a tight sequence in the SFR-M_* plane at high
redshift, whose scatter increases with time alongside with the consolidation of
the passive sequence. We also confirm the anti-correlation between sSFR and
stellar mass, pointing at a key role of the former in determining the galaxy
downsizing, as the most significant means of diagnostics of the star formation
efficiency. Likewise, an anti-correlation between sSFR and metallicity can be
established for the star-forming galaxies, while on the contrary more active
galaxies in terms of simple SFR are also metal-richer.
  We discuss these results in terms of the mechanisms driving the evolution
within the high- and low-mass regimes at different epochs: mergers,
feedback-driven outflows and the intrinsic variation of the star formation
efficiency.


title: Minimum numbers and Wecken theorems in topological coincidence theory. I

abstract:
  Minimum numbers measure the obstruction to removing coincidences of two given
maps (between smooth manifolds M and N of dimensions m and n, resp.). In this
paper we compare them to four distinct types of Nielsen numbers. These agree
with the classical Nielsen number when m = n (e.g. in the fixed point setting
where M = N and one of the maps is the identity map). However, in higher
codimensions m - n > 0 their definitions and computations involve distinct
aspects of differential topology and homotopy theory.
  We develop tools which help us 1.) to decide when a minimum number is equal
to a Nielsen number ("Wecken theorem"), and 2.) to determine Nielsen numbers.
Here certain homotopy theoretical criteria play a central role. E.g. failures
of the "Wecken condition" (cf. definition 1.18 below) can have very interesting
geometric consequences. The selfcoincidence case where the two maps are
homotopic turns out to be particularly illuminating.
  We give many concrete applications in special settings where M or N are
spheres, spherical space forms, projective spaces, tori, Stiefel manifolds or
Grassmannians. Already in the simplest examples an important role is played
e.g. by Kervaire invariants, all versions of Hopf invariants (a la James,
Hilton, Ganea,...) and the elements in the stable homotopy of spheres defined
by invariantly framed Lie groups.


title: Spin noise spectroscopy of quantum dot molecules

abstract:
  We discuss advantages and limitations of the spin noise spectroscopy for
characterization of interacting quantum dot systems on specific examples of
individual singly and doubly charged quantum dot molecules (QDMs). It is shown
that all the relevant parameters of the QDMs including tunneling amplitudes
with spin-conserving and spin-non-conserving interactions, decoherence rates,
Coulomb repulsions, anisotropic g-factors and the distance between the dots can
be determined by measuring properties of the spin noise power spectrum.


title: Vers une Substitution des Services Web sans Inconsistance S\'emantique

abstract:
  In order to ensure high availability of Web services, recently, a new
approach was proposed based on the use of communities. In composition, this
approach consists in replacing the failed Web service by another web service
joining a community offering the same functionality of the service failed.
However, this substitution may cause inconsistency in the semantic composition
and alter its mediation initially taken to resolve the semantic heterogeneities
between Web services. This paper presents a context oriented solution to this
problem by forcing the community to adopt the semantic of the failed web
service before the substitution in which all inputs and outputs to/from the
latter must be converted according to this adopted semantic, avoiding any
alteration of a semantic mediation in web service composition.


title: Nonlinear approximation theory for the homogeneous Boltzmann equation

abstract:
  A challenging problem in solving the Boltzmann equation numerically is that
the velocity space is approximated by a finite region. Therefore, most methods
are based on a truncation technique and the computational cost is then very
high if the velocity domain is large. Moreover, sometimes, non-physical
conditions have to be imposed on the equation in order to keep the velocity
domain bounded. In this paper, we introduce the first nonlinear approximation
theory for the Boltzmann equation. Our nonlinear wavelet approximation is
non-truncated and based on a nonlinear, adaptive spectral method associated
with a new wavelet filtering technique and a new formulation of the equation. A
complete and new theory to study the method is provided. The method is proved
to converge and perfectly preserve most of the properties of the homogeneous
Boltzmann equation. It could also be considered as a general frame work for
approximating kinetic integral equations.


title: A local-global principle for small triangulated categories

abstract:
  Local cohomology functors are constructed for the category of cohomological
functors on an essentially small triangulated category T equipped with an
action of a commutative noetherian ring. This is used to establish a
local-global principle and to develop a notion of stratification, for T and the
cohomological functors on it, analogous to such concepts for compactly
generated triangulated categories.


title: Nielsen numbers in topological coincidence theory

abstract:
  We discuss coincidences of pairs (f_1, f_2) of maps between manifolds. We
recall briefly the definition of four types of Nielsen numbers which arise
naturally from the geometry of generic coincidences. They are lower bounds for
the minimum numbers MCC and MC which measure to some extend the 'essential'
size of a coincidence phenomenon.
  In the setting of fixed point theory these Nielsen numbers all coincide with
the classical notion but in general they are distinct invariants.
  We illustrate this by many examples involving maps from spheres to the real,
complex or quaternionic projective space KP(n'). In particular, when n' is odd
and K = R or C or when n' = 23 mod 24 and K = H, we compute the minimum number
MCC and all four Nielsen numbers for every pair of these maps, and we establish
a 'Wecken theorem' in this context (in the process we correct also a mistake in
previous work concerning the quaternionic case). However, when n' is even,
counterexamples can occur, detected e.g. by Kervaire invariants.


title:
Transmission Spectroscopy of the Hot-Jupiter WASP-12b from 0.7 to 5
  microns

abstract:
  Since the first report of a potentially non-solar carbon-to-oxygen ratio
(C/O) in its dayside atmosphere, the highly irradiated exoplanet WASP-12b has
been under intense scrutiny and the subject of many follow-up observations.
Additionally, the recent discovery of stellar binary companions ~1" from
WASP-12 has obfuscated interpretation of the observational data. Here we
present new ground-based multi-object transmission-spectroscopy observations of
WASP-12b that we acquired over two consecutive nights in the red optical with
Gemini-N/GMOS. After correcting for the influence of WASP-12's stellar
companions, we find that these data rule out a cloud-free, H2 atmosphere with
no additional opacity sources. We detect features in the transmission spectrum
that may be attributed to metal oxides (such as TiO and VO) for an O-rich
atmosphere or to metal hydrides (such as TiH) for a C-rich atmosphere. We also
reanalyzed NIR transit-spectroscopy observations of WASP-12b from HST/WFC3 and
broadband transit photometry from Warm Spitzer. We attribute the broad spectral
features in the WFC3 data to either H2O or CH4 and HCN for an O-rich or C-rich
atmosphere, respectively. The Spitzer data suggest shallower transit depths
than the models predict at infrared wavelengths, albeit at low statistical
significance. A multi-instrument, broad-wavelength analysis of WASP-12b
suggests that the transmission spectrum is well approximated by a simple
Rayleigh scattering model with a planet terminator temperature of 1870 +/- 130
K. We conclude that additional high-precision data and isolated spectroscopic
measurements of the companion stars are required to place definitive
constraints on the composition of WASP-12b's atmosphere.


title:
Anomalous behavior in the phonon dispersion of the (001) surface of
  Bi$_2$Te$_3$ determined from helium atom-surface scattering measurements

abstract:
  We employ inelastic helium atom-surface scattering to measure the low energy
phonon dispersion along high-symmetry directions on the surface of the
topological insulator Bi$_2$Te$_3$. Results indicate that one particular
low-frequency branch experiences noticeable mode softening attributable to the
interaction between Dirac fermion quasiparticles and phonons on the surface.
This mode softening constitutes a renormalization of the real part of the
phonon self-energy. We obtain the imaginary part, and hence lifetime
information, via a Hilbert transform. In doing so we are able to calculate an
average branch specific electron-phonon coupling constant $<\lambda_\nu> =
1.44$.


title: Kervaire invariants and selfcoincidences

abstract:
  Minimum numbers decide e.g. whether a given map f: S^m --> S^n/G from a
sphere into a spherical space form can be deformed to a map f' such that f(x)
not equal f'(x) for all x in S^m. In this paper we compare minimum numbers to
(geometrically defined) Nielsen numbers (which are more computable). In the
stable dimension range these numbers coincide. But already in the first
nonstable range (when m=2n-2) the Kervaire invariant appears as a decisive
additional obstruction which detects interesting geometric coincidence
phenomena. Similar results (involving e.g. Hopf invariants, taken mod 4) are
obtained in the next seven dimension ranges (when 1<m-2n+3<9). The
selfcoincidence context yields also a precise geometric criterion for the open
question whether the Kervaire invariant vanishes on the 126-stem or not.


title: Nielsen coincidence numbers, Hopf invariants and spherical space forms

abstract:
  Given two maps between smooth manifolds, the obstruction to removing their
coincidences (via homotopies) is measured by minimum numbers. In order to
determine them we introduce and study an infinite hierarchy of Nielsen numbers
N_i, i = 0, 1, ..., \infty. They approximate the minimum numbers from below
with decreasing accuracy, but they are (in principle) more easily computable as
i grows. If the domain and the target manifold have the same dimension (e.g. in
the fixed point setting) all these Nielsen numbers agree with the classical
definition. However, in general they can be quite distinct.
  While our approach is very geometric the computations use the techniques of
homotopy theory and, in particular, all versions of Hopf invariants (a la
Ganea, Hilton, James..). As an illustration we determine all Nielsen numbers
and minimum numbers for pairs of maps from spheres to spherical space forms.
Maps into even dimensional real projective spaces turn out to produce
particularly interesting coincidence phenomena.


title: On form factors and Macdonald polynomials

abstract:
  We are developing the algebraic construction for form factors of local
operators in the sinh-Gordon theory proposed in [B.Feigin, M.Lashkeivch, 2008].
We show that the operators corresponding to the null vectors in this
construction are given by the degenerate Macdonald polynomials with rectangular
partitions and the parameters $t=-q$ on the unit circle. We obtain an integral
representation for the null vectors and discuss its simple applications.


title: A note on the acquaintance time of random graphs

abstract:
  In this short note, we prove the conjecture of Benjamini, Shinkar, and Tsur
on the acquaintance time $AC(G)$ of a random graph $G \in G(n,p)$. It is shown
that asymptotically almost surely $AC(G) = O(\log n / p)$ for $G \in G(n,p)$,
provided that $pn > (1+\epsilon) \log n$ for some $\epsilon > 0$ (slightly
above the threshold for connectivity). Moreover, we show a matching lower bound
for dense random graphs, which also implies that asymptotically almost surely
$K_n$ cannot be covered with $o(\log n / p)$ copies of a random graph $G \in
G(n,p)$, provided that $pn > n^{1/2+\epsilon}$ and $p < 1-\epsilon$ for some
$\epsilon>0$. We conclude the paper with a small improvement on the general
upper bound showing that for any $n$-vertex graph $G$, we have $AC(G) =
O(n^2/\log n)$.


title: Almost all k-cop-win graphs contain a dominating set of cardinality k

abstract:
  We consider $k$-cop-win graphs in the binomial random graph $G(n,1/2).$ It is
known that almost all cop-win graphs contain a universal vertex. We generalize
this result and prove that for every $k \in N$, almost all $k$-cop-win graphs
contain a dominating set of cardinality $k$. From this it follows that the
asymptotic number of labelled $k$-cop-win graphs of order $n$ is equal to
$(1+o(1)) (1-2^{-k})^{-k} {n \choose k} 2^{n^2/2 - (1/2-\log_2(1-2^{-k})) n}$.


title: Toppling numbers of complete and random graphs

abstract:
  We study a two-person game played on graphs based on the widely studied
chip-firing game. Players Max and Min alternately place chips on the vertices
of a graph. When a vertex accumulates as many chips as its degree, it fires,
sending one chip to each neighbour; this may in turn cause other vertices to
fire. The game ends when vertices continue firing forever. Min seeks to
minimize the number of chips played during the game, while Max seeks to
maximize it. When both players play optimally, the length of the game is the
{\em toppling number} of a graph $G$, and is denoted by $\tg(G)$.
  By considering strategies for both players and investigating the evolution of
the game with differential equations, we provide asymptotic bounds on the
toppling number of the complete graph. In particular, we prove that for
sufficiently large $n$ $$0.596400 n^2 < \tg(K_n) < 0.637152 n^2.$$ Using a
fractional version of the game, we couple the toppling numbers of complete
graphs and the binomial random graph $G(n,p)$. It is shown that for $pn \ge
n^{2/\sqrt{\log n}}$ asymptotically almost surely
$t(G(n,p))=(1+o(1))p\tg(K_n)$.


title: On the multi-Koszul property for connected algebras

abstract:
  In this article we introduce the notion of multi-Koszul algebra for the case
of a locally finite dimensional nonnegatively graded connected algebra, as a
generalization of the notion of (generalized) Koszul algebras defined by R.
Berger for homogeneous algebras, which were in turn an extension of Koszul
algebras introduced by S. Priddy. It also extends and generalizes the
definition recently introduced by the author and A. Rey.
  In order to simplify the exposition we consider the minimal graded projective
resolution of the algebra A as a bimodule, which may be used to compute the
corresponding Hochschild (co)homology groups. This new definition includes
several new interesting examples, e.g. the super Yang-Mills algebras introduced
by M. Movshev and A. Schwarz, which are not generalized Koszul or even
multi-Koszul for the previous definition given by the author and Rey. On the
other hand, we provide an equivalent description of the new definition in terms
of the Tor (or Ext) groups, and we show that several of the typical homological
computations performed for the generalized Koszul algebras are also possible in
this more general setting. In particular, we give an explicit description of
the A_infinity-algebra structure of the Yoneda algebra of a multi-Koszul
algebra. We also show that a finitely generated multi-Koszul algebra with a
finite dimensional space of relations is a K_2 algebra in the sense of T.
Cassidy and B. Shelton.


title: High Level Pattern Classification via Tourist Walks in Networks

abstract:
  Complex networks refer to large-scale graphs with nontrivial connection
patterns. The salient and interesting features that the complex network study
offer in comparison to graph theory are the emphasis on the dynamical
properties of the networks and the ability of inherently uncovering pattern
formation of the vertices. In this paper, we present a hybrid data
classification technique combining a low level and a high level classifier. The
low level term can be equipped with any traditional classification techniques,
which realize the classification task considering only physical features (e.g.,
geometrical or statistical features) of the input data. On the other hand, the
high level term has the ability of detecting data patterns with semantic
meanings. In this way, the classification is realized by means of the
extraction of the underlying network's features constructed from the input
data. As a result, the high level classification process measures the
compliance of the test instances with the pattern formation of the training
data. Out of various high level perspectives that can be utilized to capture
semantic meaning, we utilize the dynamical features that are generated from a
tourist walker in a networked environment. Specifically, a weighted combination
of transient and cycle lengths generated by the tourist walk is employed for
that end. Interestingly, our study shows that the proposed technique is able to
further improve the already optimized performance of traditional classification
techniques.


title: X-ray and EUV Observations of GOES C8 Solar Flare Events

abstract:
  We present an analysis of soft X-ray (SXR) and extreme-ultraviolet (EUV)
observations of solar flares with an approximate C8 GOES class. Our constraint
on peak GOES SXR flux allows for the investigation of correlations between
various flare parameters. We show that the the duration of the decay phase of a
flare is proportional to the duration of its rise phase. Additionally, we show
significant correlations between the radiation emitted in the flare rise and
decay phases. These results suggest that the total radiated energy of a given
flare is proportional to the energy radiated during the rise phase alone. This
partitioning of radiated energy between the rise and decay phases is observed
in both SXR and EUV wavelengths. Though observations from the EVE show
significant variation in the behavior of individual EUV spectral lines during
different C8 events, this work suggests that broadband EUV emission is well
constrained. Furthermore, GOES and AIA data, allow us to determine several
thermal parameters (e.g. temperature, volume, density, and emission measure)
for the flares within our sample. Analysis of these parameters demonstrate
that, within this constrained GOES class, the longer duration solar flares are
cooler events with larger volumes capable of emitting vast amounts of
radiation. The shortest C8 flares are typically the hottest events, smaller in
physical size, and have lower associated total energies. These relationships
are directly comparable with several scaling laws and flare loop models.


title: Bilu-Linial Stable Instances of Max Cut and Minimum Multiway Cut

abstract:
  We investigate the notion of stability proposed by Bilu and Linial. We obtain
an exact polynomial-time algorithm for $\gamma$-stable Max Cut instances with
$\gamma \geq c\sqrt{\log n}\log\log n$ for some absolute constant $c > 0$. Our
algorithm is robust: it never returns an incorrect answer; if the instance is
$\gamma$-stable, it finds the maximum cut, otherwise, it either finds the
maximum cut or certifies that the instance is not $\gamma$-stable. We prove
that there is no robust polynomial-time algorithm for $\gamma$-stable instances
of Max Cut when $\gamma < \alpha_{SC}(n/2)$, where $\alpha_{SC}$ is the best
approximation factor for Sparsest Cut with non-uniform demands.
  Our algorithm is based on semidefinite programming. We show that the standard
SDP relaxation for Max Cut (with $\ell_2^2$ triangle inequalities) is integral
if $\gamma \geq D_{\ell_2^2\to \ell_1}(n)$, where $D_{\ell_2^2\to \ell_1}(n)$
is the least distortion with which every $n$ point metric space of negative
type embeds into $\ell_1$. On the negative side, we show that the SDP
relaxation is not integral when $\gamma < D_{\ell_2^2\to \ell_1}(n/2)$.
Moreover, there is no tractable convex relaxation for $\gamma$-stable instances
of Max Cut when $\gamma < \alpha_{SC}(n/2)$. That suggests that solving
$\gamma$-stable instances with $\gamma =o(\sqrt{\log n})$ might be difficult or
impossible.
  Our results significantly improve previously known results. The best
previously known algorithm for $\gamma$-stable instances of Max Cut required
that $\gamma \geq c\sqrt{n}$ (for some $c > 0$) [Bilu, Daniely, Linial, and
Saks]. No hardness results were known for the problem. Additionally, we present
an algorithm for 4-stable instances of Minimum Multiway Cut. We also study a
relaxed notion of weak stability.


title:
Grassmann integral and Balian-Br\'ezin decomposition in
  Hartree-Fock-Bogoliubov matrix elements

abstract:
  We present a new formula to calculate matrix elements of a general unitary
operator with respect to Hartree-Fock-Bogoliubov states allowing multiple
quasi-particle excitations. The Balian-Br\'ezin decomposition of the unitary
operator (Il Nuovo Cimento B 64, 37 (1969)) is employed in the derivation. We
found that this decomposition is extremely suitable for an application of
Fermion coherent state and Grassmann integrals in the quasi-particle basis. The
resultant formula is compactly expressed in terms of the Pfaffian, and shows
the similar bipartite structure to the formula that we have previously derived
in the bare-particles basis (Phys. Lett. B 707, 305 (2012)).


title:
Electron pockets and pseudogap asymmetry observed in the thermopower of
  underdoped cuprates

abstract:
  We calculate the diffusion thermoelectric power of high-Tc cuprates using the
resonating-valence-bond spin-liquid model developed by Yang, Rice and Zhang
(YRZ). In this model, reconstruction of the energy-momentum dispersion results
in a pseudogap in the density of states that is heavily asymmetric about the
Fermi level. The subsequent asymmetry in the spectral conductivity is found to
account for the large magnitude and temperature dependence of the thermopower
observed in underdoped cuprates. In addition we find evidence in experimental
data for electron pockets in the Fermi surface, arising from a YRZ-like
reconstruction, near the onset of the pseudogap in the slightly overdoped
regime.


title:
Parity sheaves on the affine Grassmannian and the Mirkovi\'c-Vilonen
  conjecture

abstract:
  We prove the Mirkovi\'c-Vilonen conjecture: the integral local intersection
cohomology groups of spherical Schubert varieties on the affine Grassmannian
have no p-torsion, as long as p is outside a certain small and explicitly given
set of prime numbers. (Juteau has exhibited counterexamples when p is a bad
prime.) The main idea is to convert this topological question into an algebraic
question about perverse-coherent sheaves on the dual nilpotent cone using the
Juteau-Mautner-Williamson theory of parity sheaves.


title: A note on the Duffin-Schaeffer conjecture with slow divergence

abstract:
  For a non-negative function $\psi: ~ \N \mapsto \R$, let $W(\psi)$ denote the
set of real numbers $x$ for which the inequality $|n x - a| < \psi(n)$ has
infinitely many coprime solutions $(a,n)$. The Duffin--Schaeffer conjecture,
one of the most important unsolved problems in metric number theory, asserts
that $W(\psi)$ has full measure provided {equation} \label{dsccond}
\sum_{n=1}^\infty \frac{\psi(n) \varphi(n)}{n} = \infty. {equation} Recently
Beresnevich, Harman, Haynes and Velani proved that $W(\psi)$ has full measure
under the \emph{extra divergence} condition $$ \sum_{n=1}^\infty \frac{\psi(n)
\varphi(n)}{n \exp(c (\log \log n) (\log \log \log n))} = \infty \qquad
\textrm{for some $c>0$}. $$ In the present note we establish a \emph{slow
divergence} counterpart of their result: $W(\psi)$ has full measure,
provided\eqref{dsccond} holds and additionally there exists some $c>0$ such
that $$ \sum_{n=2^{2^h}+1}^{2^{2^{h+1}}} \frac{\psi(n) \varphi(n)}{n} \leq
\frac{c}{h} \qquad \textrm{for all \quad $h \geq 1$.} $$


title: Universal extra dimensions after Higgs discovery

abstract:
  We show bounds on five- and six-dimensional universal extra dimension (UED)
models from the latest results of the Higgs searches at the LHC and from the
electroweak precision data for the S and T parameters. We consider the minimal
UED model in five dimensions and the ones in six dimensions. The highest
possible ultraviolet cutoff scale for each UED model is evaluated from the
electroweak vacuum stability by solving the renormalization group equation of
the Higgs self-coupling. This scale turns out to be lower than the conventional
one obtained from the perturbativity of the gauge coupling. The resultant 95%
C.L. lower bounds on the first Kaluza-Klein scale from the LHC results and from
the S, T analysis are 600 and 700 GeV in the minimal UED model, while those in
the six-dimensional UED models are 800-1300 GeV and 900-1500 GeV, respectively.


title: Observing coronal nanoflares in active region moss

abstract:
  The High-resolution Coronal Imager (Hi-C) has provided Fe XII 193A images of
the upper transition region moss at an unprecedented spatial (~0.3-0.4 arcsec)
and temporal (5.5s) resolution. The Hi-C observations show in some moss regions
variability on timescales down to ~15s, significantly shorter than the minute
scale variability typically found in previous observations of moss, therefore
challenging the conclusion of moss being heated in a mostly steady manner.
These rapid variability moss regions are located at the footpoints of bright
hot coronal loops observed by SDO/AIA in the 94A channel, and by Hinode/XRT.
The configuration of these loops is highly dynamic, and suggestive of slipping
reconnection. We interpret these events as signatures of heating events
associated with reconnection occurring in the overlying hot coronal loops,
i.e., coronal nanoflares. We estimate the order of magnitude of the energy in
these events to be of at least a few $10^{23}rg, also supporting the nanoflare
scenario. These Hi-C observations suggest that future observations at
comparable high spatial and temporal resolution, with more extensive
temperature coverage are required to determine the exact characteristics of the
heating mechanism(s).


title:
Comparison and Analysis of Twist Pitch Length Test Methods for ITER
  Nb3Sn and NbTi Strands

abstract:
  A twisted multifilamentary structure is needed for Nb3Sn and NbTi strands to
be used in the International Thermonuclear Experimental Reactor (ITER) magnets.
As important parameters for the superconducting strands design and production,
the twist pitch length and direction of strands must meet the requirements
according to ITER Procurement Arrangement (PA) and this must be verified. The
technical requirements are 15mm+/-2mm for twist pitch length and right hand
twist for direction. The strand twist pitch and the twist direction can be
measured on straight sections of strand, which is recognized by the repetition
of filament bundles or by the angle of the filaments. Several test methods and
results are described and compared in this paper. The accuracy, uncertainty and
feasibility of different methods are analyzed and recommended measurement
methods are proposed for ITER strands verification.


title: Supersymmetry-generated complex optical potentials with real spectra

abstract:
  We show that the formalism of supersymmetry (SUSY), when applied to
parity-time (PT) symmetric optical potentials, can give rise to novel
refractive index landscapes with altogether non-trivial properties. In
particular, we find that the presence of gain and loss allows for arbitrarily
removing bound states from the spectrum of a structure. This is in stark
contrast to the Hermitian case, where the SUSY formalism can only address the
fundamental mode of a potential. Subsequently we investigate isospectral
families of complex potentials that exhibit entirely real spectra, despite the
fact that their shapes violate PT-symmetry. Finally, the role of SUSY
transformations in the regime of spontaneously broken PT symmetry is
investigated.


title: Unsatisfiable Cores for Constraint Programming

abstract:
  Constraint Programming (CP) solvers typically tackle optimization problems by
repeatedly finding solutions to a problem while placing tighter and tighter
bounds on the solution cost. This approach is somewhat naive, especially for
soft-constraint optimization problems in which the soft constraints are mostly
satisfied. Unsatisfiable-core approaches to solving soft constraint problems in
Boolean Satisfiability (e.g. MAXSAT) force all soft constraints to hold
initially. When solving fails they return an unsatisfiable core, as a set of
soft constraints that cannot hold simultaneously. Using this information the
problem is relaxed to allow certain soft constraint(s) to be violated and
solving continues. Since Lazy Clause Generation (LCG) solvers can also return
unsatisfiable cores we can adapt the MAXSAT unsatisfiable core approach to CP.
We implement the original MAXSAT unsatisfiable core solving algorithms WPM1,
MSU3 in a state-of-the-art LCG solver and show that there exist problems which
benefit from this hybrid approach.


title: A T(b) Theorem on Product Spaces

abstract:
  The main result of this paper is a bi-parameter T(b) theorem for the case
that b is a tensor product of two pseudo-accretive functions. In the proof, we
also discuss the L^2 boundedness of different types of the b-adapted
bi-parameter paraproducts.


title: Physics at the ILC with focus mostly on Higgs physics

abstract:
  Physics at the ILC is reviewed focusing mostly on Higgs physics. It is
emphasized that at the ILC it is possible to measure the $hZZ$ coupling totally
model independently, which in turn allows model-independent normalization of
various branching ratio measurements and consequently the absolute measurements
of corresponding couplings. Combining them with the measurements of the top
Yukawa coupling and the Higgs self-coupling at higher energies, the full ILC
program is shown to allow a precision test of the mass-coupling relation.


title:
Exotic quantum holonomy and non-Hermitian degeneracies in two-body
  Lieb-Liniger model

abstract:
  An interplay of an exotic quantum holonomy and exceptional points is examined
in one-dimensional Bose systems. The eigenenergy anholonomy, in which Hermitian
adiabatic cycle induces nontrivial change in eigenenergies, can be interpreted
as a manifestation of eigenenergy's Riemann surface structure, where the branch
points are identified as the exceptional points which are degeneracy points in
the complexified parameter space. It is also shown that the exceptional points
are the divergent points of the non-Abelian gauge connection for the gauge
theoretical formulation of the eigenspace anholonomy. This helps us to evaluate
anti-path-ordered exponentials of the gauge connection to obtain gauge
covariant quantities.

categories: quant-ph cond-mat.quant-gas math-ph math.MP


title: Online Vertex Cover and Matching: Beating the Greedy Algorithm

abstract:
  In this paper, we explicitly study the online vertex cover problem, which is
a natural generalization of the well-studied ski-rental problem. In the online
vertex cover problem, we are required to maintain a monotone vertex cover in a
graph whose vertices arrive online. When a vertex arrives, all its incident
edges to previously arrived vertices are revealed to the algorithm. For
bipartite graphs with the left vertices offline (i.e. all of the left vertices
arrive first before any right vertex), there are algorithms achieving the
optimal competitive ratio of $\frac{1}{1-1/e}\approx 1.582$.
  Our first result is a new optimal water-filling algorithm for this case. One
major ingredient of our result is a new charging-based analysis, which can be
generalized to attack the online fractional vertex cover problem in general
graphs. The main contribution of this paper is a 1.901-competitive algorithm
for this problem. When the underlying graph is bipartite, our fractional
solution can be rounded to an integral solution. In other words, we can obtain
a vertex cover with expected size at most 1.901 of the optimal vertex cover in
bipartite graphs.
  The next major result is a primal-dual analysis of our algorithm for the
online fractional vertex cover problem in general graphs, which implies the
dual result of a 0.526-competitive algorithm for online fractional matching in
general graphs. Notice that both problems admit a well-known 2-competitive
greedy algorithm. Our result in this paper is the first successful attempt to
beat the greedy algorithm for these two problems.
  On the hardness side, we show that no randomized online algorithm can achieve
a competitive ratio better than 1.753 and 0.625 for the online fractional
vertex cover problem and the online fractional matching problem respectively,
even for bipartite graphs.


title: Khovanov homology for alternating tangles

abstract:
  We describe a "concentration on the diagonal" condition on the Khovanov
complex of tangles, show that this condition is satisfied by the Khovanov
complex of the single crossing tangles, and prove that it is preserved by
alternating planar algebra compositions. Hence, this condition is satisfied by
the Khovanov complex of all alternating tangles. Finally, in the case of links,
our condition is equivalent to a well known result which states that the
Khovanov homology of a non-split alternating link is supported on two
diagonals. Thus our condition is a generalization of Lee's Theorem to the case
of tangles


title:
D-brane Superpotentials and Ooguri-Vafa Invariants of Compact Calabi-Yau
  Threefolds

abstract:
  We calculate the D-brane superpotentials for two non-Fermat type compact
Calabi-Yau manifolds which are the hypersurfaces of the weighed projective
spaces in type II string theory. By constructing the open-closed mirror maps,
we also compute the Ooguri-Vafa invariants, which are related to the open
Gromov-Witten invariants.


title: Directed nonabelian sandpile models on trees

abstract:
  We define two general classes of nonabelian sandpile models on directed trees
(or arborescences) as models of nonequilibrium statistical phenomena. These
models have the property that sand grains can enter only through specified
reservoirs, unlike the well-known abelian sandpile model.
  In the Trickle-down sandpile model, sand grains are allowed to move one at a
time. For this model, we show that the stationary distribution is of product
form. In the Landslide sandpile model, all the grains at a vertex topple at
once, and here we prove formulas for all eigenvalues, their multiplicities, and
the rate of convergence to stationarity. The proofs use wreath products and the
representation theory of monoids.

categories: math.PR cond-mat.stat-mech math-ph math.CO math.GR math.MP


title: Poisson deformations and birational geometry

abstract:
  Let \pi: Y -> X be a crepant projective resolution of an affine symplectic
variety X with a good C^*-action.
  We interpret the second cohomology H^2(Y, C) in two ways. First, H^2(Y, C) is
the Picard group of Y tensorised with C. By the ample cones of different
crepant resolutions of X, there is a natural chamber structure in H^2(Y, C).
The second interpretation of H^2(Y, C) is the base space of the universal
Poisson deformation $\mathcal Y$ of Y. Let D \subset H^2(Y, C) be the locus
where the corresponding Poisson varieties are not affine. Then D is the union
of finite number of hyperplanes, which gives a chamber structure in H^2(Y, C).
  These two chamber structures coincide.


title: Finite Energy Electroweak Dyon

abstract:
  The recent MoEDAL experiment at LHC to detect the electroweak monopole makes
the theoretical prediction of the monopole mass an urgent issue. We discuss
different ways to estimate the mass of the electroweak monopole. We first
present a scaling argument which indicates that the mass of the electroweak
monopole to be around 4 TeV. To justify this we construct finite energy
analytic dyon solutions which could be viewed as the regularized Cho-Maison
dyon, modifying the coupling strengths of the electromagnetic interaction of
$W$-boson in the standard model. Our result demonstrates that a genuine
electroweak monopole whose mass scale is much smaller than the grand
unification scale can exist, which can actually be detected at the present LHC.


title:
Multi-axis inertial sensing with long-time point source atom
  interferometry

abstract:
  We show that light-pulse atom interferometry with atomic point sources and
spatially resolved detection enables multi-axis (two rotation, one
acceleration) precision inertial sensing at long interrogation times. Using
this method, we demonstrate a light-pulse atom interferometer for Rb-87 with
1.4 cm peak wavepacket separation and a duration of 2T = 2.3 seconds. The
inferred acceleration sensitivity of each shot is 6.7 * 10^(-12) g, which
improves on previous limits by more than two orders of magnitude. We also
measure the Earth's rotation rate with a precision of 200 nrad/s.


title:
Large quantum superpositions of a levitated nanodiamond through
  spin-optomechanical coupling

abstract:
  We propose a method to generate and detect large quantum superposition states
and arbitrary Fock states for the oscillational mode of an optically levitated
nanocrystal diamond. The nonlinear interaction required for the generation of
non-Gaussian quantum states is enabled through the spin-mechanical coupling
with a built-in nitrogen-vacancy center inside the nanodiamond. The proposed
method allows the generation of large superpositions of nanoparticles with
millions of atoms and the observation of the associated spatial quantum
interference under reasonable experimental conditions.


title: Dilatonic Scalar Field: A Dynamical System Analysis

abstract:
  The work deals with homogeneous and isotropic, flat FRW model of the universe
which is filled up with non-interacting dark matter and dark energy to
compatible with recent observational evidences. By choosing the dark energy in
the form of a dilatonic scalar field, the evolution equations are reduced to an
autonomous system. A phase space analysis is done around the critical points
and stability criteria is examined. Finally, cosmological implications of the
nature of the critical points are discussed.


title:
Platform Deformation Phase Correction for the AMiBA-13 Co-planar
  Interferometer

abstract:
  We present a new way to solve the platform deformation problem of co-planar
interferometers. The platform of a co-planar interferometer can be deformed due
to driving forces and gravity. A deformed platform will induce extra components
into the geometric delay of each baseline, and change the phases of observed
visibilities. The reconstructed images will also be diluted due to the errors
of the phases. The platform deformations of The Yuan-Tseh Lee Array for
Microwave Background Anisotropy (AMiBA) were modelled based on photogrammetry
data with about 20 mount pointing positions. We then used the differential
optical pointing error between two optical telescopes to fit the model
parameters in the entire horizontal coordinate space. With the platform
deformation model, we can predict the errors of the geometric phase delays due
to platform deformation with given azimuth and elevation of the targets and
calibrators. After correcting the phases of the radio point sources in the
AMiBA interferometric data, we recover 50% - 70% flux loss due to phase errors.
This allows us to restore more than 90% of a source flux. The method outlined
in this work is not only applicable to the correction of deformation for other
co-planar telescopes but also to single dish telescopes with deformation
problems. This work also forms the basis of the upcoming science results of
AMiBA-13.


title: The Extended Parameter Filter

abstract:
  The parameters of temporal models, such as dynamic Bayesian networks, may be
modelled in a Bayesian context as static or atemporal variables that influence
transition probabilities at every time step. Particle filters fail for models
that include such variables, while methods that use Gibbs sampling of parameter
variables may incur a per-sample cost that grows linearly with the length of
the observation sequence. Storvik devised a method for incremental computation
of exact sufficient statistics that, for some cases, reduces the per-sample
cost to a constant. In this paper, we demonstrate a connection between
Storvik's filter and a Kalman filter in parameter space and establish more
general conditions under which Storvik's filter works. Drawing on an analogy to
the extended Kalman filter, we develop and analyze, both theoretically and
experimentally, a Taylor approximation to the parameter posterior that allows
Storvik's method to be applied to a broader class of models. Our experiments on
both synthetic examples and real applications show improvement over existing
methods.


title: Shapes of pored membranes

abstract:
  We study the shapes of pored membranes within the framework of the Helfrich
theory under the constraints of fixed area and pore size. We show that the mean
curvature term leads to a budding- like structure, while the Gaussian curvature
term tends to flatten the membrane near the pore; this is corroborated by
simulation. We propose a scheme to deduce the ratio of the Gaussian rigidity to
the bending rigidity simply by observing the shape of the pored membrane. This
ratio is usually difficult to measure experimentally. In addition, we briefly
discuss the stability of a pore by relaxing the constraint of a fixed pore size
and adding the line tension. Finally, the flattening effect due to the Gaussian
curvature as found in studying pored membranes is extended to two-component
membranes. We find that sufficiently high contrast between the components'
Gaussian rigidities leads to budding which is distinct from that due to the
line tension.


title:
Exact Green's function of the reversible ABCD reaction in two space
  dimensions

abstract:
  We derive an exact expression for the Green's functions in the time domain of
the reversible diffusion-influenced ABCD reaction $A+B\leftrightarrow C+D$ in
two space dimensions. Furthermore, we calculate the corresponding survival and
reaction probabilities. The obtained expressions should prove useful for the
study of reversible membrane-bound reactions in cell biology and can serve as a
useful ingredient of enhanced stochastic particle-based simulation algorithms.


title: Class Imbalance Problem in Data Mining Review

abstract:
  In last few years there are major changes and evolution has been done on
classification of data. As the application area of technology is increases the
size of data also increases. Classification of data becomes difficult because
of unbounded size and imbalance nature of data. Class imbalance problem become
greatest issue in data mining. Imbalance problem occur where one of the two
classes having more sample than other classes. The most of algorithm are more
focusing on classification of major sample while ignoring or misclassifying
minority sample. The minority samples are those that rarely occur but very
important. There are different methods available for classification of
imbalance data set which is divided into three main categories, the algorithmic
approach, data-preprocessing approach and feature selection approach. Each of
this technique has their own advantages and disadvantages. In this paper
systematic study of each approach is define which gives the right direction for
research in class imbalance problem.


title: Constructions of round fold maps on $C^{\infty}$ bundles

abstract:
  In this paper, we construct round fold maps or stable fold maps with
concentric singular value sets introduced by the author on smooth bundles over
spheres or bundles over more general manifolds. The class of round fold maps
includes special generic maps on spheres and such maps have been constructed on
smooth bundles over standard spheres of dimensions larger than 1 and connected
sums of smooth bundles over standard spheres of dimensions larger than 1 whose
fibers are standard spheres, for example, in previous studies by the author. In
this paper, we obtain round fold maps and the diffeomorphism types of their
source manifolds which do not appear in these studies in new manners.