title: Constraining Neutrino Mass from Neutrinoless Double Beta Decay

abstract:
  We re-analyze the compatibility of the claimed observation of neutrinoless
double beta decay ($0\nu\beta\beta$) in $^{76}$Ge with the new limits on the
half-life of $^{136}$Xe from EXO-200 and KamLAND-Zen. Including recent
calculations of the nuclear matrix elements (NMEs), we show that while the
claim in $^{76}$Ge is still compatible with the individual limits from
$^{136}$Xe, it is inconsistent with the KamLAND-Zen+EXO-200 combined limit for
all but one NME calculations. After imposing the most stringent upper limit on
the sum of light neutrino masses from Planck, we find that the canonical light
neutrino contribution cannot satisfy the claimed $0\nu\beta\beta$ signature or
saturate the current limit, irrespective of the NME uncertainties. However,
inclusion of the heavy neutrino contributions, arising naturally in TeV-scale
Left-Right symmetric models, can saturate the current limit of
$0\nu\beta\beta$. In a type-II seesaw framework, this imposes a lower limit on
the lightest neutrino mass. Depending on the mass hierarchy, we obtain this
limit to be in the range of 0.07 - 4 meV for a typical choice of the
right-handed (RH) gauge boson and RH neutrino masses relevant for their
collider searches. Using the $0\nu\beta\beta$ bounds, we also derive correlated
constraints in the RH sector, complimentary to those from the LHC.


title: On the congruence kernel of isotropic groups over rings

abstract:
  Let R be a connected noetherian commutative ring, and let G be a simply
connected reductive group over R of isotropic rank ge 2. The elementary
subgroup E(R) of G(R) is the subgroup generated by the R-points U_P^+(R) and
U_P^-(R) of the unipotent radicals of two opposite parabolic subgroups P^+ and
P^- of G. Assume that 2 is invertible in R if G is of type B_n,C_n,F_4,G_2 and
3 is invertible in R if G is of type G_2. We prove that the congruence kernel
of E(R), defined as the kernel of the natural homomorphism between the
profinite completion of E(R) and the congruence completion of E(R) with respect
to congruence subgroups of finite index, is central. In the course of the
proof, we construct Steinberg groups associated to isotropic reductive groups
and show that they are central extensions of E(R) if R is a local ring.


title:
On subdirect factors of a projective module and applications to system
  theory

abstract:
  We extend a result of Napp Avelli, van der Put, and Rocha with a
system-theoretic interpretation to the noncommutative case: Let P be a f.g.
projective module over a two-sided Noetherian domain. If P admits a subdirect
product structure of the form P = M x_T L over a factor module T of grade at
least 2 then the torsion-free factor of M (resp. L) is projective.


title:
Clustering of periodic orbits and ensembles of truncated unitary
  matrices

abstract:
  Periodic orbits in chaotic systems form clusters, whose elements traverse
approximately the same points of the phase space. The distribution of cluster
sizes depends on the length n of orbits and the parameter p which controls
closeness of orbits actions. We show that counting of cluster sizes in the
baker's map can be turned into a spectral problem for an ensemble of truncated
unitary matrices. Based on the conjecture of the universality for the
eigenvalues distribution at the spectral edge of these ensembles, we obtain
asymptotics of the second moment of cluster distribution in a regime where both
n and p tend to infinity. This result allows us to estimate the average cluster
size as a function of the number of encounters in periodic orbits.


title:
Complexity penalized hydraulic fracture localization and moment tensor
  estimation under limited model information

abstract:
  In this paper we present a novel technique for micro-seismic localization
using a group sparse penalization that is robust to the focal mechanism of the
source and requires only a velocity model of the stratigraphy rather than a
full Green's function model of the earth's response. In this technique we
construct a set of perfect delta detector responses, one for each detector in
the array, to a seismic event at a given location and impose a group sparsity
across the array. This scheme is independent of the moment tensor and exploits
the time compactness of the incident seismic signal. Furthermore we present a
method for improving the inversion of the moment tensor and Green's function
when the geometry of seismic array is limited. In particular we demonstrate
that both Tikhonov regularization and truncated SVD can improve the recovery of
the moment tensor and be robust to noise. We evaluate our algorithm on
synthetic data and present error bounds for both estimation of the moment
tensor as well as localization. Furthermore we discuss the estimated moment
tensor accuracy as a function of both array geometry and fault orientation.


title: Optimal Ternary Cyclic Codes from Monomials

abstract:
  Cyclic codes are a subclass of linear codes and have applications in consumer
electronics, data storage systems, and communication systems as they have
efficient encoding and decoding algorithms. Perfect nonlinear monomials were
employed to construct optimal ternary cyclic codes with parameters $[3^m-1,
3^m-1-2m, 4]$ by Carlet, Ding and Yuan in 2005. In this paper, almost perfect
nonlinear monomials, and a number of other monomials over $\gf(3^m)$ are used
to construct optimal ternary cyclic codes with the same parameters. Nine open
problems on such codes are also presented.


title:
Distilled Single Cell Genome Sequencing and De Novo Assembly for Sparse
  Microbial Communities

abstract:
  Identification of every single genome present in a microbial sample is an
important and challenging task with crucial applications. It is challenging
because there are typically millions of cells in a microbial sample, the vast
majority of which elude cultivation. The most accurate method to date is
exhaustive single cell sequencing using multiple displacement amplification,
which is simply intractable for a large number of cells. However, there is hope
for breaking this barrier as the number of different cell types with distinct
genome sequences is usually much smaller than the number of cells.
  Here, we present a novel divide and conquer method to sequence and de novo
assemble all distinct genomes present in a microbial sample with a sequencing
cost and computational complexity proportional to the number of genome types,
rather than the number of cells. The method is implemented in a tool called
Squeezambler. We evaluated Squeezambler on simulated data. The proposed divide
and conquer method successfully reduces the cost of sequencing in comparison
with the naive exhaustive approach.
  Availability: Squeezambler and datasets are available under
http://compbio.cs.wayne.edu/software/squeezambler/.


title:
Coexistence of the superconducting energy gap and pseudogap above and
  below the transition temperature of superconducting cuprates

abstract:
  We express the superconducting gap, $\Delta(T)$, in terms of thermodynamic
functions in both $s$- and d-wave symmetries. Applying to
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ and
Y$_{0.8}$Ca$_{0.2}$Ba$_2$Cu$_3$O$_{7-\delta}$ we find that for all dopings
$\Delta(T)$ persists, as a partial gap, high above $T_c$ due to strong
superconducting fluctuations. Therefore in general two gaps are present above
$T_c$, the superconducting gap and the pseudogap, effectively reconciling two
highly polarized views concerning pseudogap physics.


title:
On Generalizing a Temporal Formalism for Game Theory to the Asymptotic
  Combinatorics of S5 Modal Frames

abstract:
  A temporal-theoretic formalism for understanding game theory is described
where a strict ordering relation on a set of time points $T$ defines a game on
$T$. Using this formalism, a proof of Zermelo's Theorem, which states that
every finite 2-player zero-sum game is determined, is given and an exhaustive
analysis of the game of Nim is presented. Furthermore, a combinatorial analysis
of games on a set of arbitrary time points is given; in particular, it is
proved that the number of distinct games on a set $T$ with cardinality $n$ is
the number of partial orders on a set of $n$ elements. By generalizing this
theorem from temporal modal frames to S5 modal frames, it is proved that the
number of isomorphism classes of S5 modal frames $\mathcal{F} = \ < W, R \ >$
with $|W|=n$ is equal to the partition function $p(n)$. As a corollary of the
fact that the partition function is asymptotic to the Hardy-Ramanujan number
$$\frac{1}{4\sqrt{3}n}e^{\pi \sqrt{2n/3}}$$ the number of isomorphism classes
of S5 modal frames $\mathcal{F} = \ < W, R \ >$ with $|W|=n$ is asymptotically
the Hardy-Ramanujan number. Lastly, we use these results to prove that an
arbitrary modal frame is an S5 modal frame with probability zero.


title: Dissipative Dicke model with non-linear atom-photon interaction

abstract:
  We study a generalized Dicke model, as recently realized in an atomic quantum
gas experiment, describing the collective interaction of N two-level atoms with
a single cavity mode. The model takes account of dissipation of the cavity
field, and includes a non-linear atom-photon coupling, not present in the
conventional Dicke model. We extend previous theoretical investigations of a
semiclassical model by including all quantum effects and considering finite
atom number N . Our results show good agreement between quantum expectation
values and the semiclassical model as N is increased, but also show exotic
behaviour for the corresponding quantum state as the non-linear atom-photon
coupling is varied.


title: Quantum-Limited Mirror-Motion Estimation

abstract:
  We experimentally demonstrate optomechanical motion and force measurements
near the quantum precision limits set by the quantum Cram\'er-Rao bounds
(QCRBs). Optical beams in coherent and phase-squeezed states are used to
measure the motion of a mirror under an external stochastic force. Utilizing
optical phase tracking and quantum smoothing techniques, we achieve position,
momentum, and force estimation accuracies close to the QCRBs with the coherent
state, while estimation using squeezed states shows clear quantum enhancements
beyond the coherent-state bounds.


title:
A Physical Link Between Jet Formation and Hot Plasma in Active Galactic
  Nuclei

abstract:
  Recent observations suggest that in black hole X-ray binaries jet/outflow
formation is related to the hot plasma in the vicinity of the black hole,
either in the form of an advection-dominated accretion flow at low accretion
rates or in a disk corona at high accretion rates. We test the viability of
this scenario for supermassive black holes using two samples of active galactic
nuclei distinguished by the presence (radio-strong) and absence (radio-weak) of
well-collimated, relativistic jets. Each is centered on a narrow range of black
hole mass but spans a very broad range of Eddington ratios, effectively
simulating, in a statistical manner, the behavior of a single black hole
evolving across a wide spread in accretion states. Unlike the relationship
between the radio and optical luminosity, which shows an abruptly break between
high- and low-luminosity sources at an Eddington ratio of ~1, the radio
emission-a measure of the jet power-varies continuously with the hard X-ray
(2-10 keV) luminosity, roughly as L_R \propto L_X^(0.6-0.75). This relation,
which holds for both radio-weak and radio-strong active galaxies, is similar to
the one seen in X-ray binaries. Jet/outflow formation appears to be closely
linked to the conditions that give rise to the hot, optically thin coronal
emission associated with accretion flows, both in the regime of low and high
accretion rates.


title:
Parasitic nonlinearities in photon pair generation via integrated
  spontaneous four-wave mixing: critical problem or distraction?

abstract:
  We consider integrated photon pair sources based on spontaneous four-wave
mixing and derive expressions for the pump powers at which various nonlinear
processes become relevant for a variety of source materials and structures.
These expressions serve as rules of thumb in identifying reasonable parameter
regimes for the design of such sources. We demonstrate that if pump powers are
kept low enough to suppress cross-phase modulation, multi-pair events as well
as many other nonlinear effects are often also constrained to negligible
levels.


title: Ordering Metro Lines by Block Crossings

abstract:
  A problem that arises in drawings of transportation networks is to minimize
the number of crossings between different transportation lines. While this can
be done efficiently under specific constraints, not all solutions are visually
equivalent. We suggest merging crossings into block crossings, that is,
crossings of two neighboring groups of consecutive lines. Unfortunately,
minimizing the total number of block crossings is NP-hard even for very simple
graphs. We give approximation algorithms for special classes of graphs and an
asymptotically worst-case optimal algorithm for block crossings on general
graphs. That is, we bound the number of block crossings that our algorithm
needs and construct worst-case instances on which the number of block crossings
that is necessary in any solution is asymptotically the same as our bound.


title:
Dark Matter and Gauge Coupling Unification in A Supersymmetry Model with
  Vector-like Matter

abstract:
  WIMP dark matter and gauge coupling unification are considered in an R-parity
violating MSSM with vector-like matter. Dark matter is contained in an
additional vector-like SU(2)$_L$ doublet which possesses a new U(1) gauge
symmetry. The Higgs fields are extended to be in a ${\bf 5\oplus \bar{5}}$
representation of SU(5). The stability of dark matter is a result of gauge
symmetries, and the mass of the dark matter particle is between (1.1-1.5) TeV.
Dark matter has a very small cross section with nucleis, thus the model is
consistent with current dark matter direct detection experiments such as
Xenon100. The model also predicts new charged and colored particles to be
observed at LHC.


title:
Cohomology ring of the BRST operator associated to the sum of two pure
  spinors

abstract:
  In the study of the Type II superstring, it is useful to consider the BRST
complex associated to the sum of two pure spinors. The cohomology of this
complex is an infinite-dimensional vector space. It is also a
finite-dimensional algebra over the algebra of functions of a single pure
spinor. In this paper we study the multiplicative structure.


title:
Warping of accretion disk and launching of jet by a spinning black hole
  in NGC 4258

abstract:
  We fit the most updated broadband spectral energy distribution from radio to
X-rays for NGC 4258 with a coupled accretion-jet model that surrounding a Kerr
black hole (BH), where both the jet and the warped H_2O maser disk are assumed
to be triggered by a spinning BH through Blandford-Znajek mechanism and
Bardeen-Petterson effect respectively. The accretion flow consists with an
inner radiatively inefficient accretion flow (RIAF) and an outer truncated
standard thin disk, where the transition radius R_tr~3*10^3Rg for NGC 4258
based on the width and variability of its narrow Fe K$\alpha$ line. The hybrid
jet formation model, as a variant of Blandford-Znajek model, is used to model
the jet power. Therefore, we can estimate the accretion rate and BH spin
through the two observed quantities--X-ray emission and jet power, where the
observed jet power is estimated from the low-frequency radio emission. Through
this method, we find that the BH of NGC 4258 should be mildly spinning with
dimensionless spin parameter a_*=0.7\pm0.2. The outer thin disk mainly radiates
at near infrared waveband and the jet contributes predominantly at radio
waveband. Using above estimated BH spin and the inferred accretion rate at the
region of the maser disk based on the physical existence of the H_2 O maser, we
find that the warp radius is ~8.6*10^4 R_g if it is driven by the
Bardeen-Petterson effect, which is consistent with the observational result
very well.


title:
Dark Matter Phase Transition Constrained at O(0.1) eV with LSB Rotation
  Curves

abstract:
  In order to unravel the nature of the dark matter (DM) we have proposed a
particle-physics motivated model called Bound Dark Matter (BDM) that consist in
DM massless particles above a threshold energy Ec that acquire mass below it
due to nonperturbative methods. Therefore, the BDM model describes DM particles
which are relativistic, hot dark matter (HDM) in the denser (inner) regions of
galaxies and describes nonrelativistic, cold dark matter (CDM) where halo
density is below rho_c = Ec^4. We test this model by fitting rotation curves
from Low Surface Brightness (LSB) galaxies from The HI Nearby Galaxy Survey
(THINGS). We use a particular DM cored profile that contains three parameters:
a typical scale length (rs) and density (rho_0) of the halo, and a core radius
(rc) stemming from the relativistic nature of the BDM model. Since the energy
Ec parameterizes the phase transition due to the underlying particle physics
model, it is independent on the details of galaxy and/or structure formation
and therefore the DM profile parameters rs, rc, Ec are constrained, leaving
only two free parameters. Through the results we agree with previous ones
implying that cored profiles are preferred over the N-body motivated cuspy
profiles. We also compute 2D likelihoods of the BDM parameters rc and Ec for
the different galaxies and matter contents, and find an average galaxy core
radius rc = 1.48kpc and a transition energy between hot and cold dark matter at
Ec = 0.06 eV. The phase transition scale Ec is a new fundamental scale for our
DM model well motivated theoretical origin from gauge group dynamics.


title: Doubling construction of Calabi-Yau threefolds

abstract:
  We give a differential-geometric construction and examples of Calabi-Yau
threefolds, at least one of which is {\it{new}}. Ingredients in our
construction are {\it admissible pairs}, which were dealt with by Kovalev in
\cite{K03} and further studied by Kovalev and Lee in \cite{KL11}. An admissible
pair $(\overline{X},D)$ consists of a three-dimensional compact K\"{a}hler
manifold $\overline{X}$ and a smooth anticanonical $K3$ divisor $D$ on
$\overline{X}$. If two admissible pairs $(\overline{X}_1,D_1)$ and
$(\overline{X}_2,D_2)$ satisfy the {\it gluing condition}, we can glue
$\overline{X}_1\setminus D_1$ and $\overline{X}_2\setminus D_2$ together to
obtain a Calabi-Yau threefold $M$. In particular, if $(\overline{X}_1,D_1)$ and
$(\overline{X}_2,D_2)$ are identical to an admissible pair $(\overline{X},D)$,
then the gluing condition holds automatically, so that we can {\it always}
construct a Calabi-Yau threefold from a {\it single} admissible pair
$(\overline{X},D)$ by {\it doubling} it. Furthermore, we can compute all Betti
and Hodge numbers of the resulting Calabi-Yau threefolds in the doubling
construction.


title:
Kondo effect in monolayer and bilayer graphene: physical realizations of
  the multi-channel Kondo models

abstract:
  We perform a general group-theoretical study of the Kondo problem in
monolayer and bilayer graphene around the charge neutrality point. Utilizing
the group representation theory, we derive from symmetry considerations a
family of the Kondo models for all symmetric placements with either 3- or
6-fold rotational axis of an impurity atom in an arbitrary orbital state. We
find six possible classes of the partially anisotropic four-channel Kondo
model. As the key result, we argue several possibilities to realize the regime
of the dominant channel-symmetric two-channel Kondo effect, protected by the
local symmetry and specifics of the graphene band structure. Our findings open
prospects for the observation of the rich multi-channel Kondo physics in
graphene and the associated non-Fermi-liquid behavior.


title:
Submillimeter H2O Maser in Circinus Galaxy - A New Probe for the
  Circumnuclear Region of Active Galactic Nuclei

abstract:
  We present the first detection of extragalactic submillimeter H2O maser in
the 321 GHz transition toward the center of Circinus galaxy, the nearby Type 2
Seyfert using the Atacama Large Millimeter/Submillimeter Array. We find that
Doppler features of the detected 321 GHz H2O maser straddle the systemic
velocity of the galaxy as seen in the spectrum of the known 22 GHz H2O maser in
the galaxy. By comparing the velocities of the maser features in both
transitions, it can be deduced that the 321 GHz maser occurs in a region
similar to that of the 22 GHz maser, where the sub-parsec-scale distribution of
the 22 GHz maser was revealed by earlier very long baseline interferometry
observations. The detected maser features remain unresolved at the synthesized
beam of ~0".66 (~15 pc) and coincide with the 321 GHz continuum peak within
small uncertainties. We also present a tentative detection of the highest
velocity feature (redshifts up to ~635 km/s) in the galaxy. If this
high-velocity feature arises from a Keplerian rotating disk well established in
this galaxy, it is located at a radius of ~0.018 pc (~1.2 x 10^5 Schwarzschild
radii), which might probe molecular material closest to the central engine.


title:
A proof of the Alexanderov's uniqueness theorem for convex surfaces in
  $\mathbb R^3$

abstract:
  We give a new proof of a classical uniqueness theorem of Alexandrov using the
weak uniqueness continuation theorem of Bers-Nirenberg. We prove a version of
this theorem with the minimal regularity assumption: the spherical hessians of
the corresponding convex bodies as Radon measures are nonsingular.


title:
Gradient bounds for p-harmonic systems with vanishing neumann data in a
  convex domain

abstract:
  Let $ \ti \Om $ be a bounded convex domain in Euclidean $ n $ space, $ \hat x
\in \ar \ti \Om, $ and $ r > 0. $ Let $ \ti u = (\ti u^1, \ti u^2, \dots, \ti
u^N) $ be a weak solution to \[\nabla \cdot \left (|\nabla \ti u |^{p-2} \nabla
\ti u \right) = 0 \mbox{in} \ti \Om \cap B (\hat x, 4 r) \mbox{with} |\nabla
\ti u|^{p-2} \, \ti u_\nu = 0 \mbox{on} \ar \ti \Om \cap B (\hat x, 4 r). \] We
show that sub solution type arguments for certain uniformly elliptic systems
can be used to deduce that $ | \nabla \ti u | $ is bounded in $ \ti \Om \cap B
(\hat x, r)$ with constants depending only on $ n, p, N. $ and $ \frac{r^n}{|
\ti \Om \cap B (\hat x, r) |}.$ Our argument replaces an argument based on
level sets in recent important work of [CM], [CM1], [GS], [M], [M1], involving
similar problems.


title: About uniform regularity of collections of sets

abstract:
  We further investigate the uniform regularity property of collections of sets
via primal and dual characterizing constants. These constants play an important
role in determining convergence rates of projection algorithms for solving
feasibility problems.


title: Describing groups using first-order language

abstract:
  We investigate two notions about descriptions of groups using first-order
language: quasi-finite axiomatizability, concerning infinite groups, and
polylogarithmic compressibility, concerning classes of finite groups.


title:
Transport and the first passage time problem with application to cold
  atoms in optical traps

abstract:
  Measurements of spatial diffusion of cold atoms in optical lattices have
revealed anomalous super-diffusion, which is controlled by the depth of the
optical lattice. We use first passage time statistics to derive the diffusion
front of the atoms. In particular, the distributions of areas swept under the
first passage curve till its first arrival, and of areas under the Bessel
excursion are shown to be powerful tools in the analysis of the atomic cloud. A
rather general relation between first passage time statistics and diffusivity
is discussed, showing that first passage time analysis is a useful tool in the
calculation of transport coefficients. A brief introduction to the
semi-classical description of Sisyphus cooling is provided which yields a rich
phase diagram for the dynamics.


title:
The impact of astrophysical particle acceleration on searches for
  beyond-the-Standard-Model physics

abstract:
  A brief white paper is provided, discussing how the particle acceleration
mechanisms taking place within astrophysical sources may mimic or mask
signatures of new physics and the role that will be played by next-generation
gamma-ray observatories, such as the Cherenkov Telescope Array, in improving
our understanding of these phenomena.


title:
Quantization of B-I electrodynamics and B-I modified gravity using
  Faddeev-Popov gauge-fixing procedure

abstract:
  We investigate the quantized versions of Born Infeld electrodynamics and Born
Infeld Gravity. We derive Feynman rules for B-I electrodynamics by deriving an
effective Lagrangian with the square root removed using the Faddeev-Popov
method. In the case of B-I gravity, the square root in the Lagrangian is
removed by the introduction of the Vierbien fields. This approach has the
advantage that SO(3,1) can be consistently regarded to be the gauge group of
gravity. Finally, using a rough argument, the quantum fluctuations of the radii
of spatial hypersurfaces in flat space are shown to undergo accelerated
increase with time.


title: AMS-02 Positrons from Decaying Wino in the Pure Gravity Mediation Model

abstract:
  The AMS-02 collaboration has recently reported an excess of the cosmic-ray
positron fraction, which turned out to be consistent with previous results
reported by the PAMELA and Fermi-LAT collaborations. A decaying dark matter
with the mass around 1 TeV can be responsible for the excess of the positron
fraction when it is interpreted as a dark matter signal. Interestingly, the
pure gravity mediation model provides such a dark matter, namely an almost pure
neutral wino dark matter, when a tiny R-parity violation through $LLE^c$
interactions is introduced. We show that the decaying wino dark matter well
reproduces the energy spectrum of the fraction with being consistent with
constraints from cosmic-ray anti-proton and gamma-ray observations.


title: Pricing Public Goods for Private Sale

abstract:
  We consider the pricing problem faced by a seller who assigns a price to a
good that confers its benefits not only to its buyers, but also to other
individuals around them. For example, a snow-blower is potentially useful not
only to the household that buys it, but also to others on the same street.
Given that the seller is constrained to selling such a (locally) public good
via individual private sales, how should he set his prices given the
distribution of values held by the agents?
  We study this problem as a two-stage game. In the first stage, the seller
chooses and announces a price for the product. In the second stage, the agents
(each having a private value for the good) decide simultaneously whether or not
they will buy the product. In the resulting game, which can exhibit a
multiplicity of equilibria, agents must strategize about whether they will
themselves purchase the good to receive its benefits.
  In the case of a fully public good (where all agents benefit whenever any
agent purchases), we describe a pricing mechanism that is approximately
revenue-optimal (up to a constant factor) when values are drawn from a regular
distribution. We then study settings in which the good is only "locally"
public: agents are arranged in a network and share benefits only with their
neighbors. We describe a pricing method that approximately maximizes revenue,
in the worst case over equilibria of agent behavior, for any $d$-regular
network. Finally, we show that approximately optimal prices can be found for
general networks in the special case that private values are drawn from a
uniform distribution. We also discuss some barriers to extending these results
to general networks and regular distributions.


title: Homotopy theory for algebras over polynomial monads

abstract:
  We study the existence and left properness of transferred model structures
for "monoid-like" objects in monoidal model categories. These include genuine
monoids, but also all kinds of operads as for instance symmetric, cyclic,
modular, higher operads, properads and PROP's. All these structures can be
realised as algebras over polynomial monads.
  We give a general condition for a polynomial monad which ensures the
existence and (relative) left properness of a transferred model structure for
its algebras. This condition is of a combinatorial nature and singles out a
special class of polynomial monads which we call tame polynomial. Many
important monads are shown to be tame polynomial.


title: Quantile Regression for Large-scale Applications

abstract:
  Quantile regression is a method to estimate the quantiles of the conditional
distribution of a response variable, and as such it permits a much more
accurate portrayal of the relationship between the response variable and
observed covariates than methods such as Least-squares or Least Absolute
Deviations regression. It can be expressed as a linear program, and, with
appropriate preprocessing, interior-point methods can be used to find a
solution for moderately large problems. Dealing with very large problems,
\emph(e.g.), involving data up to and beyond the terabyte regime, remains a
challenge. Here, we present a randomized algorithm that runs in nearly linear
time in the size of the input and that, with constant probability, computes a
$(1+\epsilon)$ approximate solution to an arbitrary quantile regression
problem. As a key step, our algorithm computes a low-distortion
subspace-preserving embedding with respect to the loss function of quantile
regression. Our empirical evaluation illustrates that our algorithm is
competitive with the best previous work on small to medium-sized problems, and
that in addition it can be implemented in MapReduce-like environments and
applied to terabyte-sized problems.


title: The Galactic Center: Not an Active Galactic Nucleus

abstract:
  We present 10um-35um Spitzer spectra of the interstellar medium in the
Central Molecular Zone (CMZ), the central 210 pc x 60 pc of the Galactic center
(GC). We present maps of the CMZ in ionic and H2 emission, covering a more
extensive area than earlier spectroscopic surveys in this region. The radial
velocities and intensities of ionic lines and H2 suggest that most of the H2
0-0 S(0) emission comes from gas along the line-of-sight, as found by previous
work. We compare diagnostic line ratios measured in the Spitzer Infrared Nearby
Galaxies Survey (SINGS) to our data. Previous work shows that forbidden line
ratios can distinguish star-forming galaxies from LINERs and AGNs. Our GC line
ratios agree with star-forming galaxies and not with LINERs or AGNs.


title:
Approximation Properties of a Gradient Recovery Operator Using a
  Biorthogonal System

abstract:
  A gradient recovery operator based on projecting the discrete gradient onto
the standard finite element space is considered. We use an oblique projection,
where the test and trial spaces are different, and the bases of these two
spaces form a biorthogonal system. Biorthogonality allows efficient computation
of the recovery operator.We analyse the approximation properties of the
gradient recovery operator.


title:
Conditional statistical properties of the complex systems having
  long-range interactions

abstract:
  A new concept of the available force is proposed to investigate the
performance of the complex systems having long-range interactions. Since the
covariance of average velocity in double time interval and available force
equals zero, it is possible to calculate the conditional probability
distribution function (CPDF) within the systems. It is found that the
asymmetric CPDF of the velocity between two adjacent time intervals can be
derived from the symmetrical CPDF between the available force and the double
time interval velocity. Two typical currency exchange databases, i.e., EUR/USD
and GBP/USD, which collect the minutely opening exchange prices from 1 January
1999 to 31 December 2011, are adopted as examples. It is found that the
analytical CPDF needs only six parameters for an arbitrary system. By
calculating the CPDF in the currency exchange databases, it is shown that the
results are well fitted by our analytical expression. The analytical CPDF can
be also used to calculate the conditional expectation and the conditional
variance of velocity. Interestingly, the two databases show that the
conditional expectation of the velocity between two adjacent time intervals is
not monotonic, while the conditional variance tends to monotonic. All of these
results are well described by our theory. It is worthwhile to note that the
analytical CPDF is a general expression. It is valid not only for current
exchange systems but also for any complex systems having long-range
interactions and/or long-duration memory.


title:
Energy dependence of pion in-medium effects on \pi^-/\pi^+ ratio in
  heavy-ion collisions

abstract:
  Within the framework of a thermal model with its parameters fitted to the
results from an isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport
model, we study the pion in-medium effect on the charged-pion ratio in
heavy-ion collisions at various energies. We find that due to the cancellation
between the effects from pion-nucleon s-wave and p-wave interactions in nuclear
medium, the \pi^-/\pi^+ ratio generally decreases after including the pion
in-medium effect. The effect is larger at lower collision energies as a result
of narrower pion spectral functions at lower temperatures.


title: Relativity theory in time-space

abstract:
  The concept of time-space defined in an earlier paper of the author is a
certain generalization of the so-called space-time. In this paper we introduce
the concept of time-space manifolds. In the homogeneous case, a time-space
manifold is a differentiable manifold with such tangent spaces which have a
certain fixed time-space structure. We redefine the fundamental concepts of
global relativity theory with respect to this general situation. We study the
concepts of affine connection, parallel transport, curvature tensor and
Einstein equation, respectively.


title: Weighted multidegrees of polynomial automorphisms over a domain

abstract:
  The notion of the weighted degree of a polynomial is a basic tool in Affine
Algebraic Geometry. In this paper, we study the properties of the weighted
multidegrees of polynomial automorphisms by a new approach which focuses on
stable coordinates. We also present some applications of the generalized
Shestakov-Umirbaev theory.


title:
Resonant peak splitting for graphene superlattices with one-dimensional
  periodic potentials of square barriers

abstract:
  We have investigated theoretically the resonance splitting effect of Dirac
electrons through graphene superlattices with periodic potentials of square
barriers. It is found that each resonance peak in the transmission gap presents
(N-1)-fold resonance splitting for N-barriers, which is the analogy of the case
in semiconductor superlattices. The resonance splitting effect depends on the
incidence angle rather than the height and width of potential. However, there
is no explicit splitting rule for the conductance and shot noise, which is
different from the magnetic case. These properties may lead to potential
applications in graphene-based electron devices.


title: Split quasicocycles

abstract:
  Let E be a linear isometric representation of a group \Gamma. In this paper
we construct and study a family of quasicocycles \Gamma -> E that arise from
splittings \Gamma = A * B. Under certain assumptions on A, B and E the bounded
cohomology classes associated to these quasicocycles form an
infinite-dimensional subspace of H^2_b(\Gamma,E). This is in particular the
case when \Gamma is free and E finite-dimensional or of the type l^p(\Gamma).
For the trivial target E = R we obtain a new family of quasimorphisms for which
we compute the Gromov norm in bounded cohomology. This yields a linear
isometric embedding D(A) \oplus D(B) -> H^2_b(\Gamma,R), where D(A) is a Banach
space which is norm-equivalent to the alternating subspace of l^inf(A). We
prove that there are classes of our type in H^2_b(F_2,R) which have infinite
stabilizer under the natural action of Out(F_2). By replacing the target E with
a group G with bi-invariant metric we obtain a new type of
quasi-representations \Gamma -> G that arise from splittings of \Gamma.


title:
Radiation Exposure Theory Comparison of data on Mutation Frequencies of
  Mice

abstract:
  We propose Radiation Exposure Theory (RET), a mathematical framework to
estimate biological damage caused by irradiation. This is an extension of LDM
model which was proposed in the paper [Y. Manabe et al.: J. Phys. Soc. Jpn. 81,
104004(2012)]. The theory is based on physical protocol, 'a stimulus and its
response'. It takes account of considerable response including mutation, cell
death caused by outer stimulus, as well as biological functions such as
proliferation, apoptosis and repair. By taking account of biological issues,
namely a variety of preventable effects, which is characteristic feature of
living object. RET can explain various data which simple LNT does not
reproduce. As one of the characteristic features of RET, we propose a scaling
law, namely all the data point with different dose rate irradiation are
predicted to lie on the universal line if the variables, the biological damage
function as a function of time development after artificial irradiation starts
are converted to renormalized ones. The above scaling law can be compared with
experimental data. We adopt the accumulated experiments performed by so-called
mega mouse projects. It is found that their data points are converted into a
universal scaling function and are in reasonably agreement with the prediction
of RET.


title: Degenerate Eisenstein Series for $Sp_4$

abstract:
  In this paper we obtain a complete description of images and poles of
degenerate Eisenstein series attached to maximal parabolic subgroups of
$Sp_4(\mathbb A)$, where $\mathbb A$ is the ring of adeles of $\mathbb Q$.


title: Integrable (2+1)-Dimensional Spin Models with Self-Consistent Potentials

abstract:
  Integrable spin systems possess interesting geometrical and gauge invariance
properties and have important applications in applied magnetism and
nanophysics. They are also intimately connected to the nonlinear Schr\"odinger
family of equations. In this paper, we identify three different integrable spin
systems in (2 + 1) dimensions by introducing the interaction of the spin field
with more than one scalar potential, or vector potential, or both. We also
obtain the associated Lax pairs. We discuss various interesting reductions in
(2 + 1) and (1 + 1) dimensions. We also deduce the equivalent nonlinear
Schr\"odinger family of equations, including the (2 + 1)-dimensional version of
nonlinear Schr\"odinger--Hirota--Maxwell--Bloch equations, along with their Lax
pairs.


title: Regularity in Monge's mass transfer problem

abstract:
  In this paper, we study the regularity of optimal mappings in Monge's mass
transfer problem. Using the approximation to Monge's cost function given by the
Euclidean distance c(x,y)=dist(x,y) through the costs
c_\eps(x,y)=(\eps^2+dist(x,y)^2)^{1/2}, we consider the optimal mappings T_\eps
for these costs, and we prove that the eigenvalues of the Jacobian matrix
DT_\eps, which are all positive, are locally uniformly bounded. By an example
we prove that T_\eps is in general not uniformly Lipschitz continuous as
\eps-0, even if the mass distributions are positive and smooth, and the domains
are c-convex.


title:
Symmetric vs asymmetric stem cell divisions: an adaptation against
  cancer?

abstract:
  Traditionally, it has been held that a central characteristic of stem cells
is their ability to divide asymmetrically. Recent advances in inducible genetic
labeling provided ample evidence that symmetric stem cell divisions play an
important role in adult mammalian homeostasis. It is well understood that the
two types of cell divisions differ in terms of the stem cells' flexibility to
expand when needed. On the contrary, the implications of symmetric and
asymmetric divisions for mutation accumulation are still poorly understood. In
this paper we study a stochastic model of a renewing tissue, and address the
optimization problem of tissue architecture in the context of mutant
production. Specifically, we study the process of tumor suppressor gene
inactivation which usually takes place as a sequence of two consecutive "hits",
and which is one of the most common patterns in carcinogenesis. We compare and
contrast symmetric and asymmetric (and mixed) stem cell divisions, and focus on
the rate at which double-hit mutants are generated. It turns out that
symmetrically-dividing cells generate such mutants at a rate which is
significantly lower than that of asymmetrically-dividing cells. This result
holds whether single-hit (intermediate) mutants are disadvantageous, neutral,
or advantageous. It is also independent on whether the carcinogenic double-hit
mutants are produced only among the stem cells or also among more
differentiated cells. We argue that symmetric stem cell divisions in mammals
could be an adaptation which helps delay the onset of cancers. We further
investigate the question of the optimal fraction of stem cells in the tissue,
and quantify the contribution of non-stem cells in mutant production. Our work
provides a hypothesis to explain the observation that in mammalian cells,
symmetric patterns of stem cell division seem to be very common.


title: Bubbles are rational

abstract:
  As we show using the notion of equilibrium in the theory of infinite
sequential games, bubbles and escalations are rational for economic and
environmental agents, who believe in an infinite world. This goes against a
vision of a self regulating, wise and pacific economy in equilibrium. In other
words, in this context, equilibrium is not a synonymous of stability. We
attempt to draw from this statement methodological consequences and a new
approach to economics. To the mindware of economic agents (a concept due to
cognitive psychology) we propose to add coinduction to properly reason on
infinite games. This way we refine the notion of rationality.


title: Invariance of Finiteness of K-area under Surgery

abstract:
  K-area is an invariant for Riemannian manifolds introduced by Gromov as an
obstruction to the existence of positive scalar curvature. However in general
it is difficult to determine whether K-area is finite or not. though the
definition of K-area is quite natural. In this paper, we study how the
invariant changes under surgery.


title:
Clustering Unclustered Data: Unsupervised Binary Labeling of Two
  Datasets Having Different Class Balances

abstract:
  We consider the unsupervised learning problem of assigning labels to
unlabeled data. A naive approach is to use clustering methods, but this works
well only when data is properly clustered and each cluster corresponds to an
underlying class. In this paper, we first show that this unsupervised labeling
problem in balanced binary cases can be solved if two unlabeled datasets having
different class balances are available. More specifically, estimation of the
sign of the difference between probability densities of two unlabeled datasets
gives the solution. We then introduce a new method to directly estimate the
sign of the density difference without density estimation. Finally, we
demonstrate the usefulness of the proposed method against several clustering
methods on various toy problems and real-world datasets.


title: The shape of large balls in highly supercritical percolation

abstract:
  We exploit a connection between distances in the infinite percolation
cluster, when the parameter is close to one, and the discrete-time TASEP on
$\mathbb{Z}$. This shows that when the parameter goes to one, large balls in
the cluster are asymptotically shaped near the axes like arcs of parabola.


title: Semi Markov model for market microstructure

abstract:
  We introduce a new model for describing the fluctuations of a tick-by-tick
single asset price. Our model is based on Markov renewal processes. We consider
a point process associated to the timestamps of the price jumps, and marks
associated to price increments. By modeling the marks with a suitable Markov
chain, we can reproduce the strong mean-reversion of price returns known as
microstructure noise. Moreover, by using Markov renewal processes, we can model
the presence of spikes in intensity of market activity, i.e. the volatility
clustering, and consider dependence between price increments and jump times. We
also provide simple parametric and nonparametric statistical procedures for the
estimation of our model. We obtain closed-form formula for the mean signature
plot, and show the diffusive behavior of our model at large scale limit. We
illustrate our results by numerical simulations, and that our model is
consistent with empirical data on the Euribor future.


title:
Scanning Gate Microscopy of Kondo Dots: Fabry-P\'erot Interferences and
  Thermally Induced Rings

abstract:
  We study the conductance of an electron interferometer formed in a two
dimensional electron gas between a nanostructured quantum contact and the
charged tip of a scanning gate microscope. Measuring the conductance as a
function of the tip position, thermally induced rings may be observed in
addition to Fabry-P\'erot interference fringes spaced by half the Fermi
wavelength. If the contact is made of a quantum dot opened in the middle of a
Kondo valley, we show how the location of the rings allows to measure by
electron interferometry the magnetic moment of the dot above the Kondo
temperature.


title:
Assessment of range-separated time-dependent density-functional theory
  for calculating C6 dispersion coefficients

abstract:
  We assess a variant of linear-response range-separated time-dependent
density-functional theory (TDDFT), combining a long-range Hartree-Fock (HF)
exchange kernel with a short-range adiabatic exchange-correlation kernel in the
local-density approximation (LDA) for calculating isotropic C6 dispersion
coefficients of homodimers of a number of closed-shell atoms and small
molecules. This range-separated TDDFT tends to give underestimated C6
coefficients of small molecules with a mean absolute percentage error of about
5%, a slight improvement over standard TDDFT in the adiabatic LDA which tends
to overestimate them with a mean absolute percentage error of 8%, but close to
time-dependent Hartree-Fock which has a mean absolute percentage error of about
6%. These results thus show that introduction of long-range HF exchange in
TDDFT has a small but beneficial impact on the values of C6 coefficients. It
also confirms that the present variant of range-separated TDDFT is a reasonably
accurate method even using only a LDA-type density functional and without
adding an explicit treatment of long-range correlation.


title:
First-principles generalized gradient approximation (GGA) +Ud+Up studies
  of electronic structures and optical properties in cubic HfO2

abstract:
  The electronic structures and optical properties of cubic HfO2 are calculated
by means of generalized gradient approximation (GGA) +U approach. Without
on-site Coulomb interactions, the band gap of cubic HfO2 is 2.92eV, much lower
than the experimental value (5.7eV). Introducing the Coulomb interactions of 5d
orbitals on Hf atom (Ud) and of 2p orbitals on O atom (Up), we can reproduce
the experimental value of the band gap. The calculated dielectric function of
cubic HfO2 by the GGA+ Ud + Up approach predicts the presence of a shoulder
structure below the main peak of the absorption spectrum. These indicate that
the GGA +Ud +UP approach is a convenient and powerful method to calculate and
predict the electronic structures and the optical properties of wide-gap
optical materials.


title:
Radiative corrections to the Higgs boson couplings in the Higgs triplet
  model

abstract:
  We calculate Higgs coupling constants at one-loop level in the Higgs triplet
model (HTM) to compare to future collider experiments. We evaluate the decay
rate of the standard model (SM)-like Higgs boson ($h$) into diphoton.
Renormalized Higgs couplings with the weak gauge bosons $hVV$ ($V=W$\ and\ $Z$)
and the trilinear coupling $hhh$ are also calculated at the one-loop level in
the on-shell scheme. The event rate of the $pp\rightarrow h \rightarrow
\gamma\gamma$ channel in the HTM to the one in the SM can cover the value from
the recent LHC data. We find that in the allowed parameter region by the
current data, deviations in the one-loop corrected $hVV$ and $hhh$ vertices can
be about -1% and +50%, respectively. Magnitudes of these deviations can be
enough significant to compare with the precision future data at the
International Linear Collider.


title: Combinatorial Pair Testing: Distinguishing Workers from Slackers

abstract:
  We formalize a problem we call combinatorial pair testing (CPT), which has
applications to the identification of uncooperative or unproductive
participants in pair programming, massively distributed computing, and
crowdsourcing environments. We give efficient adaptive and nonadaptive CPT
algorithms and we show that our methods use an optimal number of testing rounds
to within constant factors. We also provide an empirical evaluation of some of
our methods.


title: Bures Distance For Completely Positive Maps

abstract:
  D. Bures had defined a metric on the set of normal states on a von Neumann
algebra using GNS representations of states. This notion has been extended to
completely positive maps between $C^*$-algebras by D. Kretschmann, D.
Schlingemann and R. F. Werner. We present a Hilbert $C^*$-module version of
this theory. We show that we do get a metric when the completely positive maps
under consideration map to a von Neumann algebra. Further, we include several
examples and counter examples. We also prove a rigidity theorem, showing that
representation modules of completely positive maps which are close to the
identity map contain a copy of the original algebra.


title: Sums of class numbers and mixed mock modular forms

abstract:
  In this paper, we consider sums of class numbers of the type $\sum_{m\equiv
a\pmod{p}} H(4n-m^2)$, where $p$ is an odd prime, $n\in \mathbb{N},$ and $a\in
\mathbb{Z}$. By showing that these are coefficients of mixed mock modular
forms, we obtain explicit formulas. Using these formulas for $p=5$ and $7$, we
then prove a conjecture of Brown et al. in the case that $n=\ell$ is prime.


title:
Divergence in age-patterns of mortality change drives international
  divergence in lifespan inequality

abstract:
  In the past six decades, lifespan inequality has varied greatly within and
among countries even while life expectancy has continued to increase. How and
why does mortality change generate this diversity? We derive a precise link
between changes in age-specific mortality and lifespan inequality, measured as
the variance of age at death. Key to this relationship is a young-old threshold
age, below and above which mortality decline respectively decreases and
increases lifespan inequality. First, we show that shifts in the threshold's
location modified the correlation between changes in life expectancy and
lifespan inequality over the last two centuries. Second, we analyze the post
Second World War trajectories of lifespan inequality in a set of developed
countries, Japan, Canada and the United States (US), where thresholds centered
on retirement age. Our method reveals how divergence in the age-pattern of
mortality change drives international divergence in lifespan inequality. Most
strikingly, early in the 1980s, mortality increases in young US males led
lifespan inequality to remain high in the US, while in Canada the decline of
inequality continued. In general, our wider international comparisons show that
mortality change varied most at young working ages after the Second World War,
particularly for males. We conclude that if mortality continues to stagnate at
young ages, yet declines steadily at old ages, increases in lifespan inequality
will become a common feature of future demographic change.


title: Realizing Universal Majorana Fermionic Quantum Computation

abstract:
  Majorana-fermionic quantum computation (MFQC) was proposed by Bravyi and
Kitaev (See Ref.\cite{Kitaev}), in which a fault-torrent (non-topological)
quantum computer built from Majorana fermions may be more efficient than that
built from distinguishable two-state systems. However, till now people don't
know how to realize a MFQC in a physical system. In this paper we proposed a
possible realization of MFQC. We find that the end of a line-defect of p-wave
superconductor or superfluid on a honeycomb lattice will trap a Majorana zero
mode, which will become the starting point of MFQC. Then we show how to
manipulate Majorana fermions to do universal MFQC, which possesses unique
possibilities for high-level local controllability, individual addressing, and
readout of the quantum states of individual constituent elements by using
timely cold-atom technology.

categories: cond-mat.str-el cond-mat.quant-gas cond-mat.supr-con quant-ph


title:
Small-amplitude inhomogeneous plane waves in a deformed Mooney-Rivlin
  material

abstract:
  The propagation of small-amplitude inhomogeneous plane waves in an isotropic
homogeneous incompressible Mooney--Rivlin material is considered when the
material is maintained in a state of finite static homogeneous deformation.
Disturbances of complex exponential type are sought and all propagating
inhomogeneous solutions to the equations of motion are given, as well as the
conditions for linear, elliptical, or circular polarization. % It is seen that
a great variety of solutions arises. These include some original solutions,
such as circularly-polarized plane waves which propagate with an arbitrary
complex scalar slowness, or linearly-polarized waves for which the direction of
propagation is not necessarily orthogonal to the direction of attenuation. %
Throughout the paper, geometrical interpretations and explicit examples are
presented.


title: Reconstruction of Missing Data using Iterative Harmonic Expansion

abstract:
  In the cosmic microwave background or galaxy density maps, missing
fluctuations in masked regions can be reconstructed from fluctuations in the
surrounding unmasked regions if the original fluctuations are sufficiently
smooth. One reconstruction method involves applying a harmonic expansion
iteratively to fluctuations in the unmasked region. In this paper, we discuss
how well this reconstruction method can recover the original fluctuations
depending on the prior of fluctuations and property of the masked region. The
reconstruction method is formulated with an asymptotic expansion in terms of
the size of mask for a fixed iteration number. The reconstruction accuracy
depends on the mask size, the spectrum of the underlying density fluctuations,
the scales of the fluctuations to be reconstructed and the number of
iterations. For Gaussian fluctuations with the Harrison--Zel'dovich spectrum,
the reconstruction method provides more accurate restoration than naive methods
based on brute--forth matrix inversion or the singular value decomposition. We
also demonstrate that an isotropic non-Gaussian prior does not change the
results but an anisotropic non-Gaussian prior can yield a higher reconstruction
accuracy compared to the Gaussian prior case.


title: Triezenberg-Zwanzig expression for the surface tension of a liquid drop

abstract:
  Formulas, analogous to the Triezenberg-Zwanzig expression for the surface
tension of a planar interface, are presented for the Tolman length, the bending
rigidity, and the rigidity constant associated with Gaussian curvature. These
expressions feature the Ornstein-Zernike direct correlation function and are
derived from considering the deformation of a liquid drop in the presence of an
external field. This approach is in line with the original analysis by Yvon in
1948. It is shown that our expressions reduce to previous results from density
functional theory when a mean-field approximation is made for the direct
correlation function. We stress the importance of the form of the external
field used and show how the values of the rigidity constants depend on it.


title:
Thermal form factors of the XXZ chain and the large-distance asymptotics
  of its temperature dependent correlation functions

abstract:
  We derive expressions for the form factors of the quantum transfer matrix of
the spin-1/2 XXZ chain which are suitable for taking the infinite Trotter
number limit. These form factors determine the finitely many amplitudes in the
leading asymptotics of the finite-temperature correlation functions of the
model. We consider form-factor expansions of the longitudinal and transversal
two-point functions. Remarkably, the formulae for the amplitudes are in both
cases of the same form. We also explain how to adapt our formulae to the
description of ground state correlation functions of the finite chain. The
usefulness of our novel formulae is demonstrated by working out explicit
results in the high- and low-temperature limits. We obtain, in particular, the
large-distance asymptotics of the longitudinal two-point functions for small
temperatures by summing up the asymptotically most relevant terms in the form
factor expansion of a generating function of the longitudinal correlation
functions. As expected the leading term in the expansion of the corresponding
two-point functions is in accordance with conformal field theory predictions.
Here it is obtained for the first time by a direct calculation.


title:
Global attractors and extinction dynamics of cyclically competing
  species

abstract:
  Transitions to absorbing states are of fundamental importance in
non-equilibrium physics as well as ecology. In ecology, absorbing states
correspond to the extinction of species. We here study the spatial population
dynamics of three cyclically interacting species. The interaction scheme
comprises both direct competition between species as in the cyclic
Lotka-Volterra model, and separated selection and reproduction processes as in
the May-Leonard model. We show that the dynamic processes leading to the
transient maintenance of biodiversity are closely linked to attractors of the
nonlinear dynamics for the overall species' concentrations. The characteristics
of these global attractors change qualitatively at certain threshold values of
the mobility, and depend on the relative strength of the different types of
competition between species. They give information about the scaling of
extinction times with the system size and thereby the stability of
biodiversity. We define an effective free energy as the negative logarithm of
the probability to find the system in a specific global state before reaching
one of the absorbing states. The global attractors then correspond to minima of
this effective energy landscape and determine the most probable values for the
species' global concentrations. As in equilibrium thermodynamics, qualitative
changes in the effective free energy landscape indicate and characterize the
underlying non-equilibrium phase transitions. We provide the complete phase
diagrams for the population dynamics, and give a comprehensive analysis of the
spatio-temporal dynamics and routes to extinction in the respective phases.


title: Interval exchanges, admissibility and branching Rauzy induction

abstract:
  We introduce a definition of admissibility for subintervals in interval
exchange transformations. Using this notion, we prove a property of the natural
codings of interval exchange transformations, namely that any derived set of a
regular interval exchange set is a regular interval exchange set with the same
number of intervals. Derivation is taken here with respect to return words. We
characterize the admissible intervals using a branching version of the Rauzy
induction. We also study the case of regular interval exchange transformations
defined over a quadratic field and show that the set of factors of such a
transformation is primitive morphic. The proof uses an extension of a result of
Boshernitzan and Carroll.


title:
Electronic Structure of a Two-Dimensional Graphene-Like Topological
  Insulator, Bi14Rh3I9

abstract:
  Very recently, a new two-dimensional graphene-like topological insulator,
Bi14Rh3I9, has been synthesized. The Bi-Rh sheets with a strong spin-orbit
interaction are graphene analogues with a honeycomb net composed of RhBi8
cubes. Here we derive the low-energy effective Hamiltonian involving spin-orbit
coupling for Bi14Rh3I9. In the absence of spin-orbit coupling, the Bi-Rh sheets
show two inequivalent Dirac cones at the corners of the hexagonal Brillouin
zone. The spin-orbit interaction opens a 2400 K bandgap at the Dirac points and
establishes the quantum spin Hall effect in the Bi-Rh sheets. Our result
indicates that the Bi14Rh3I9 may combine many unique electronic properties of
graphene and topological insulators, and it should host a combination of
quantum valley and spin Hall effects.


title:
Algebro-geometric solutions and their reductions for the Fokas-Lenells
  hierarchy

abstract:
  This paper is dedicated to provide theta function representations of
algebro-geometric solutions for the Fokas-Lenells (FL) hierarchy through
studying an algebro-geometric initial value problem. Further, we reduce these
solutions into $N$-dark solutions through the degeneration of associated
Riemann surfaces.


title:
Magnetic properties in layered (K, Rb and Cs)Co2Se2 with ThCr2Si2_type
  structure

abstract:
  The magnetic properties of ThCr_2Si_2-type single crystals ACo_2Se_2 (A = K,
Rb and Cs) have been investigated by magnetic susceptibility and isothermal
magnetization measurements at various temperatures. The ferromagnetic phase
transition temperatures are estimated as $\approx$ 74 K and 76 K and 62 K for A
= K, Rb and Cs (in case of high magnetic field), respectively. The
susceptibility data in the paramagnetic state obey the modified Curie-Weiss law
quite well and the derived effective magnetic moments of the Co atom are about
2.21, 2.04 and 2.04 \mu_B/Co and the corresponding spontaneous moments derived
at the ground state are 0.72, 0.59 and 0.52 \mu_B/Co as well as the generalized
Rhodes-Wohlfarth ratios as 3.07, 3.42 and 3.96 for A= K, Rb and Cs,
respectively. The magnetic moment aligns within ab-plane and a
metamagnetism-like behavior occurs at a field of 3.5 T in CsCo_2Se_2 with
H//ab-plane. The magnetic properties in this system were discussed within the
frameworks of the self-consistent renormalization (SCR) and Takahashi's theory
of spin fluctuations.


title:
Geometry-Based Vehicle-to-Vehicle Channel Modeling for Large-Scale
  Simulation

abstract:
  Due to the dynamic nature of vehicular traffic and the road surroundings,
vehicle-to-vehicle (V2V) propagation characteristics vary greatly on both
small- and large-scale. Recent measurements have shown that both large static
objects (e.g., buildings and foliage) as well as mobile objects (surrounding
vehicles) have a profound impact on V2V communication. At the same time,
system-level Vehicular Ad Hoc Network (VANET) simulators by and large employ
simple statistical propagation models, which do not account for surrounding
objects explicitly. We designed GEMV$^2$ (Geometry-based Efficient propagation
Model for V2V communication), which uses outlines of vehicles, buildings, and
foliage to distinguish the following three types of links: line of sight (LOS),
non-LOS due to vehicles, and non- LOS due to static objects. For each link,
GEMV$^2$ calculates the large-scale signal variations deterministically,
whereas the small- scale signal variations are calculated stochastically based
on the number and size of surrounding objects. We implement GEMV$^2$ in MATLAB
and show that it scales well by using it to simulate radio propagation for
city-wide networks with tens of thousands of vehicles on commodity hardware. We
make the source code of GEMV$^2$ freely available. Finally, we validate
GEMV$^2$ against extensive measurements performed in urban, suburban, highway,
and open space environment.


title:
Search for resonant diboson production in the lvjj decay channels with
  the ATLAS detector at 7 TeV

abstract:
  A search for resonant diboson production using a data sample corresponding to
4.7 fb-1 of integrated luminosity collected by the ATLAS experiment at the
Large Hadron Collider in pp collisions at 7 TeV is presented. The search for a
narrow resonance in the WW or WZ mass distribution is conducted in a final
state with an electron or a muon, missing transverse momentum and at least two
jets. No significant excess is observed and limits are set using three
benchmark models: WW resonance masses below 940 GeV and 710 GeV are excluded at
95% confidence level for spin-2 Randall-Sundrum and bulk Randall-Sundrum
gravitons, respectively; WZ resonance masses below 950 GeV are excluded at 95%
confidence level for a spin-1 Extended Gauge Model W' boson.


title: Strong Field Ionization as an Inhomogeneous Schroedinger Equation

abstract:
  Strong field ionization is difficult to treat theoretically due to the
simultaneous need to treat bound state dynamics accurately and continuum
dynamics efficiently. We address this problem by decomposing the time dependent
Schroedinger equation (TDSE) into an inhomogeneous form, in which a precomputed
bound state acts as a source term for a time dependent tunneling component. The
resulting theory is equivalent to the full TDSE when exact propagation is used,
and reduces or eliminates a major source of wavefunction error when propagation
is approximated. The gauge invariance of the resulting theory is used to
clarify an apparent gauge dependence which has long been observed in the
context of strong field S-matrix theory.


title: The finite index basis property

abstract:
  We describe in this paper a connection between bifix codes, symbolic
dynamical systems and free groups. This is in the spirit of the connection
established previously for the symbolic systems corresponding to Sturmian
words. We introduce a class of sets of factors of an infinite word with linear
factor complexity containing Sturmian sets and regular interval exchange sets,
namemly the class of tree sets. We prove as a main result that for a uniformly
recurrent tree set $F$, a finite bifix code $X$ on the alphabet $A$ is
$F$-maximal of $F$-degree $d$ if and only if it is the basis of a subgroup of
index $d$ of the free group on $A$.


title:
Robustness of quantum randomness expansion protocols in the presence of
  noise

abstract:
  In this paper we investigate properties of several randomness generation
protocols in the device independent framework. Using Bell-type inequalities it
is possible to certify that the numbers generated by an untrusted device are
indeed random. We present a selection of certificates which guarantee two bits
of randomness for each run of the experiment in the noiseless case and require
the parties to share a maximally entangled state. To compare them we study
their efficiency in the presence of white noise. We find that for different
amounts of noise different operators are optimal for certifying most
randomness. Therefore the vendor of the device should use different protocols
depending on the amount of noise expected to occur. Another of our results that
we find particularly interesting is that using a single Bell operator as a
figure of merit is rarely optimal.


title:
Diagrams of affine permutations, balanced labellings, and symmetric
  functions

abstract:
  We generalize the work of Fomin, Greene, Reiner, and Shimozono on balanced
labellings in two directions: (1) we define the diagrams of affine permutations
and the balanced labellings on them; (2) we define the set-valued version of
the balanced labellings. We show that the column-strict balanced labellings on
the diagram of an affine permutation yield the affine Stanley symmetric
function defined by Lam, and that the column-strict set-valued balanced
labellings yield the affine stable Grothendieck polynomial of Lam. Moreover,
once we impose suitable flag conditions, the flagged column-strict set-valued
balanced labellings on the diagram of a finite permutation give a monomial
expansion of the Grothendieck polynomial of Lascoux and Sch\"{u}tzenberger. We
also give a necessary and sufficient condition for a diagram to be an affine
permutation diagram.


title: Electroweak and Top Results from ATLAS

abstract:
  An overview of recent measurements of electroweak and top quark physics is
given. In particular, total and differential diboson cross sections, limits on
anomalous triple gauge couplings as well as top quark production cross sections
and properties, such as charge asymmetry, top quark polarization and Wtb vertex
measurements, are presented. Proton-proton collision data produced at the LHC
at sqrt s = 7 TeV and sqrt s = 8 TeV collected with the ATLAS detector are
used.


title: Classification of engineered topological superconductors

abstract:
  I perform a complete classification of 2d, quasi-1d and 1d topological
superconductors which originate from the suitable combination of inhomogeneous
Rashba spin-orbit coupling, magnetism and superconductivity. My analysis
reveals alternative types of topological superconducting platforms for which
Majorana fermions are accessible. Specifically, I observe that for quasi-1d
systems with Rashba spin-orbit coupling and time-reversal violating
superconductivity, as for instance due to a finite Josephson current flow,
Majorana fermions can emerge even in the absence of magnetism. Furthermore, for
the classification I also consider situations where additional "hidden"
symmetries emerge, with a significant impact on the topological properties of
the system. The latter, generally originate from a combination of space group
and complex conjugation operations that separately do not leave the Hamiltonian
invariant. Finally, I suggest alternative directions in topological quantum
computing for systems with additional unitary symmetries.


title:
Entangler via Electromagnetically Induced Transparency with Atomic
  Ensembles

abstract:
  We present an efficient and convenient scheme to entangle multiple optical
fields via electromagnetically induced transparency in an atomic ensemble. The
atomic spin wave, produced through electromagnetically induced transparency in
the Lambda-type configuration in an atomic ensemble, can be described by a Bose
operator and acts as the entangler. By using the entangler, any desired number
of nondegenerate narrow-band continuous-variable entangled fields, in
principle, can be generated through stimulated Raman scattering processes,
which holds great promise for applications in scalable quantum communication
and quantum networks.


title: Ballistic spin transport in exciton gases

abstract:
  Traditional spintronics relies on spin transport by charge carriers, such as
electrons in semiconductor crystals. This brings several complications: the
Pauli principle prevents the carriers from moving with the same speed; Coulomb
repulsion leads to rapid dephasing of electron flows. Spin-optronics is a
valuable alternative to traditional spintronics. In spin-optronic devices the
spin currents are carried by electrically neutral bosonic quasi-particles:
excitons or exciton-polaritons. They can form highly coherent quantum liquids
and carry spins over macroscopic distances. The price to pay is a finite
life-time of the bosonic spin carriers. We present the theory of exciton
ballistic spin transport which may be applied to a range of systems where
bosonic spin transport has been reported, in particular, to indirect excitons
in coupled GaAs/AlGaAs quantum wells. We describe the effect of spin-orbit
interaction of electrons and holes on the exciton spin, account for the Zeeman
effect induced by external magnetic fields, long range and short range exchange
splittings of the exciton resonances. We also consider exciton transport in the
non-linear regime and discuss the definitions of exciton spin current,
polarization current and spin conductivity.


title: An equivariant discrete model for complexified arrangement complements

abstract:
  We define a partial ordering on the set Q = Q(M) of pairs of topes of an
oriented matroid M, and show the geometric realization |Q| of the order complex
of Q has the same homotopy type as the Salvetti complex of M. For any element e
of the ground set, the complex |Qe| associated to the rank-one oriented matroid
on {e} has the homotopy type of the circle. There is a natural free simplicial
action of Z4 on |Q|, with orbit space isomorphic to the order complex of the
poset Q(M,e) associated to the pointed (or affine) oriented matroid (M,e). If M
is the oriented matroid of an arrangement A of linear hyperplanes in real
space, the Z_4 action corresponds to the diagonal action of C* on the
complement M of the complexification of A: |Q| is equivariantly
homotopy-equivalent to M under the identification of Z_4 with {+1, i, -1, -i},
and |Q(M, e)| is homotopy-equivalent to the complement of the decone of A
relative to the hyperplane corresponding to e. All constructions and arguments
are carried out at the level of the underlying posets. If a group G acts on the
set of topes of M preserving adjacency, then G acts simplicially on |Q|. We
also show that the class of fundamental groups of such complexes is strictly
larger than the class of fundamental groups of complements of complex
hyperplane arrangements. Specifically, the group of the non-Pappus arrange-
ment is not isomorphic to any realizable arrangement group.


title:
Translating cities: the use of digital technologies in urban
  environments

abstract:
  Computer models and information systems have been used for urban planning and
design since the 1950s. Their capacity for analysis and problem-solving has
increased substantially since then with hardware and software being able to
manage large amounts of data. The beginning of the 2000s brought better
technologies for data visualisation and intuitive software products and
nowadays they are being used to design and manipulate highly complex urban
systems. However, ontological and epistemological questions remain about the
nature of urban environments. What do we know about cities - and what is a city
exactly? What theoretical models can be applied to the study of cities? How do
we translate a city into data? What type of information really matters and what
do we want to communicate with them? What are the implications of computer
modelling for urban planning and design? This paper reviews how digital
technologies have been used to shape our understanding of cities and how they
impact the design and planning of cities. The point of depart is a scrutiny of
the emergence of modern planning in the nineteenth century when cities became a
scientific subject. A range of theories and concepts of the urban form and
urban growth developed during the twentieth century will be presented and then
linked to the first investigations involving the use of the computer for
modelling and planning. The paper concludes with some discussions around the
interaction of computing and urban theories.


title: Wedge operations and torus symmetries

abstract:
  A fundamental result of toric geometry is that there is a bijection between
toric varieties and fans. More generally, it is known that some class of
manifolds having well-behaved torus actions, called topological toric manifolds
$M^{2n}$, can be classified in terms of combinatorial data containing
simplicial complexes with $m$ vertices. We remark that topological toric
manifolds are a generalization of smooth toric varieties. The number $m-n$ is
known as the Picard number when $M^{2n}$ is a {compact smooth} toric variety.
  In this paper, we investigate the relationship between the topological toric
manifolds over a simplicial complex $K$ and those over the complex obtained by
simplicial wedge operations from $K$. As applications, we do the following.
  1. We classify smooth toric varieties of Picard number 3. This is a reproving
of a result of Batyrev.
  2. We give a new and complete proof of projectivity of smooth toric varieties
of Picard number 3 originally proved by Kleinschmidt and Sturmfels.
  3. We find a criterion for a toric variety over the join of boundaries of
simplices to be projective. When the toric variety is smooth, it is known as a
generalized Bott manifold which is always projective.
  4. We classify and enumerate real topological toric manifolds when $m-n=3$.
  5. When $m-n \leq 3$, any real topological toric manifold is realizable as
fixed points of the conjugation of a topological toric manifold.


title:
Renormalized vs Nonrenormalized Chiral Transition in a Magnetic
  Background

abstract:
  We study analytically the chiral phase transition for hot quark matter in
presence of a strong magnetic background, focusing on the existence of a
critical point at zero baryon chemical potential and nonzero magnetic field. We
build up a Ginzburg-Landau effective potential for the chiral condensate at
finite temperature, computing the coefficients of the expansion within a chiral
quark-meson model. Our conclusion is that the existence of the critical point
at finite $\bm B$ is very sensitive to the way the ultraviolet divergences of
the model are treated. In particular, we find that after renormalization, no
chiral critical point is present in the phase diagram. On the other hand, such
a critical point there exists when the ultraviolet divergences are not removed
by a proper renormalization of the thermodynamic potential.


title: Effect of nuclear deformation on direct capture reactions

abstract:
  The direct radiative capture process is well described by the spherical
potential model. In order for the model to explain direct captures more
accurately, the effect of the nuclear deformation has been added and analyzed
in this work, since most nucleuses are not spherical. The results imply that
the nuclear deformation largely affects the direct capture and should be taken
into account during discussing direct capture reactions.


title: Condensation of random walks and the Wulff crystal

abstract:
  We introduce a Gibbs measure on nearest-neighbour paths of length $t$ in the
Euclidean $d$-dimensional lattice, where each path is penalised by a factor
proportional to the size of its boundary and an inverse temperature $\beta$. We
prove that, for all $\beta>0$, the random walk condensates to a set of diameter
$(t/\beta)^{1/3}$ in dimension $d=2$, up to a multiplicative constant. In all
dimensions $d\ge 3$, we also prove that the volume is bounded above by
$(t/\beta)^{d/(d+1)}$ and the diameter is bounded below by
$(t/\beta)^{1/(d+1)}$. Similar results hold for a random walk conditioned to
have local time greater than $\beta$ everywhere in its range when $\beta$ is
larger than some explicit constant, which in dimension two is the logarithm of
the connective constant.


title: Hi-C & AIA observations of transverse MHD waves in active regions

abstract:
  The recent launch of the High resolution Coronal imager (Hi-C) provided a
unique opportunity to study the EUV corona with unprecedented spatial
resolution. We utilize these observations to investigate the properties of low
frequency (50-200 s) active region transverse waves, whose omnipresence had
been suggested previously. The five-fold improvement in spatial resolution over
SDO/AIA reveals coronal loops with widths 150-310 km and that these loops
support transverse waves with displacement amplitudes <50 km. However, the
results suggest that wave activity in the coronal loops is of low energy, with
typical velocity amplitudes <3 km/s. An extended time-series of SDO data
suggest low-energy wave behaviour is typical of the coronal structures both
before and after the Hi-C observations.


title: Truth versus information in logic programming

abstract:
  The semantics of logic programs was originally described in terms of
two-valued logic. Soon, however, it was realised that three-valued logic had
some natural advantages, as it provides distinct values not only for truth and
falsehood, but also for "undefined". The three-valued semantics proposed by
Fitting and by Kunen are closely related to what is computed by a logic
program, the third truth value being associated with non-termination. A
different three-valued semantics, proposed by Naish, shared much with those of
Fitting and Kunen but incorporated allowances for programmer intent, the third
truth value being associated with underspecification. Naish used an
(apparently) novel "arrow" operator to relate the intended meaning of left and
right sides of predicate definitions. In this paper we suggest that the
additional truth values of Fitting/Kunen and Naish are best viewed as duals. We
use Belnap's four-valued logic, also used elsewhere by Fitting, to unify the
two three-valued approaches. The truth values are arranged in a bilattice which
supports the classical ordering on truth values as well as the "information
ordering". We note that the "arrow" operator of Naish (and our four-valued
extension) is essentially the information ordering, whereas the classical arrow
denotes the truth ordering. This allows us to shed new light on many aspects of
logic programming, including program analysis, type and mode systems,
declarative debugging and the relationships between specifications and
programs, and successive executions states of a program. This paper is to
appear in Theory and Practice of Logic Programming (TPLP).


title: On the universal coefficients formula for shape homology

abstract:
  In this paper it is investigated whether various shape homology theories
satisfy the Universal Coefficients Formula (UCF). It is proved that
pro-homology and strong homology satisfy UCF in the class FAB of finitely
generated abelian groups, while they do not satisfy UCF in the class AB of all
abelian groups. Two new shape homology theories (called UCF-balanced) are
constructed. It is proved that balanced pro-homology satisfies UCF in the class
AB, while balanced strong homology satisfies UCF only in the class FAB.


title: Nematics, Knots and Non-orientable Surfaces

abstract:
  Knots and knotted fields enrich physical phenomena ranging from DNA and
molecular chemistry to the vortices of fluid flows and textures of ordered
media. Liquid crystals provide an ideal setting for exploring such topological
phenomena through control of their characteristic defects. The use of colloids
in generating defects and knotted configurations in liquid crystals has been
demonstrated for spherical and toroidal particles and shows promise for the
development of novel photonic devices. Extending this existing work, we
describe the full topological implications of colloids representing
non-orientable surfaces and use it to construct torus knots and links of type
($p$,2) around multiply-twisted M\"obius strips.


title: Relative Robust Portfolio Optimization

abstract:
  Considering mean-variance portfolio problems with uncertain model parameters,
we contrast the classical absolute robust optimization approach with the
relative robust approach based on a maximum regret function. Although the
latter problems are NP-hard in general, we show that tractable inner and outer
approximations exist in several cases that are of central interest in asset
management.


title:
Nanotube caps on Ni, Fe, and NiFe nano particles: A path to chirality
  selective growth

abstract:
  Carbon nanotubes have properties depending on the arrangement of carbon atoms
on the tube walls, called chirality. Also it has been tried to grow nanotubes
of only one chirality for more than a decade it is still not possible today. A
narrowing of the distribution of chiralities, however, which is a first step
towards chirality control, has been observed for the growth of nanotubes on
catalysts composed of nickel and iron. In this paper, we have calculated
carbon-metal bond energies, adhesion energies and charge distributions of
carbon nanotube caps on Ni, Fe and NiFe alloy clusters using density functional
theory. A growth model using the calculated energies was able to reproduce the
experimental data of the nanotube growth on the alloy catalysts. The electronic
charge was found to be redistributed from the catalyst particles to the edges
of the nanotube caps in dependence of the chiral angles of the caps increasing
the reactivity of the edge atoms. Our study develops an explanation for the
chirality enrichment in the carbon nanotube growth on alloy catalyst particles.


title:
Tracing the Interplay between Non-Thermal Dark Matter and Right-Handed
  Dirac Neutrinos with LHC Data

abstract:
  Llight-element abundances probing big bang nucleosynthesis and precision data
from cosmology probing the cosmic microwave background decoupling epoch have
hinted at the presence of extra relativistic degrees of freedom. This is widely
referred to as "dark radiation", suggesting the need for new light states in
the UV completion of the standard model. We provide a brief and concise
overview of the current observational status of such dark radiation and
investigate the interplay between two possible interpretations of the extra
light states: the right-handed partners of three Dirac neutrinos (which
interact with all fermions through the exchange of a new heavy vector meson)
and dark matter particles that were produced through a non-thermal mechanism,
such us late time decays of massive relics. This model ties together
cosmological indications of extra light states and the production of the heavy
vector particle at the LHC.


title:
Constraints on neutrino mass ordering and degeneracy from Planck and
  neutrino-less double beta decay

abstract:
  We investigate constraints on neutrino mass ordering and degeneracy by
considering the first cosmological result based on Planck measurements of the
cosmic microwave background. It is shown that the result at 95% CL rejects a
neutrino mass degeneracy larger than 85% (82.5%) for the normal (inverted)
hierarchical case. We can also find some regions where the neutrino mass
ordering will be able to be distinguished by combining a value of sum of the
neutrino masses with an effective neutrino mass determined by neutrino-less
double beta decay experiments.


title:
Enabling high-precision 3D strong-field measurements - Ionization with
  low-frequency fields in the tunneling regime

abstract:
  Ionization of an atom or molecule presents surprising richness beyond our
current understanding: strong-field ionization with low-frequency fields
recently revealed unexpected kinetic energy structures (1, 2). A solid grasp on
electron dynamics is however pre-requisite for attosecond-resolution
recollision imaging (3), orbital tomography (4), for coherent sources of keV
light (5), or to produce zeptosecond-duration x-rays (6). We present a
methodology that enables scrutinizing strong-field dynamics at an unprecedented
level. Our method provides high-precision measurements only 1 meV above the
threshold despite 5 orders higher ponderomotive energies. Such feat was
realized with a specifically developed ultrafast mid-IR light source in
combination with a reaction microscope. We observe electron dynamics in the
tunneling regime ({\gamma} = 0.3) and show first 3D momentum distributions
demonstrating surprising new observations of near-zero momentum electrons and
low momentum structures, below the eV, despite quiver energies of 95 eV.


title:
Hall Equilibria: Solutions with toroidal and poloidal magnetic fields in
  Neutron Star Crusts

abstract:
  We present Hall equilibrium solutions for neutron stars crusts containing
toroidal and poloidal magnetic field. Some simple cases are solved analytically
while more complicated configurations are found numerically through a
Gauss-Seidel elliptic partial differential equation solver.


title:
Amplitude death and synchronized states in nonlinear time-delay systems
  coupled through mean-field diffusion

abstract:
  We explore and experimentally demonstrate the phenomena of amplitude death
(AD) and the corresponding transitions through synchronized states that lead to
AD in coupled {\it intrinsic time-delayed} hyperchaotic oscillators interacting
through mean-field diffusion. We identify a novel synchronization transition
scenario leading to AD, namely transitions among AD, generalized anticipatory
synchronization (GAS), complete synchronization (CS), and generalized lag
synchronization (GLS). This transition is mediated by variation of the
difference of {\it intrinsic time-delays} associated with the individual
systems, and has no analogue in non-delayed systems or coupled oscillators with
{\it coupling time-delay}. We further show that, for equal intrinsic
time-delays, increasing coupling strength results in a transition from the
unsynchronized state to AD state via in-phase (complete) synchronized states.
Using Krasovskii--Lyapunov theory, we derive the stability conditions that
predict the parametric region of occurrence of GAS, GLS, and CS; also, using a
linear stability analysis we derive the condition of occurrence of AD. We use
the error function of proper synchronization manifold and a modified form of
the similarity function to provide the quantitative support to GLS and GAS. We
demonstrate all the scenarios in an electronic circuit experiment; the
experimental time-series, phase-plane plots, and generalized autocorrelation
function computed from the experimental time series data are used to confirm
the occurrence of all the phenomena in the coupled oscillators.


title:
A note on the space of evolutionary operators in population genetics and
  folding dynamics

abstract:
  Discrete dynamical systems defined by the iteration of a polynomial map of
the unit simplex to itself appear in the context of population genetic systems
evolving under mutation, recombination and weak selection. Although exceptional
progress has been made in finding particular solutions to these systems, our
knowledge of the general properties of the space of all possible dynamical
systems of this kind is still limited. We prove that the space of
bounded-degree polynomial maps of the unit simplex to itself is a compact and
convex subset of a Euclidean space. We provide an explicit characterization of
such a space and of its boundary. A special class of maps in the boundary, the
folding maps, which generalize the logistic map for any dimension and degree
are defined and constructed. Finally, we use numerical methods to study the
ergodic and mixing properties of maps in the neighborhood of several of these
folding maps.


title: The Software Garden

abstract:
  This paper describes a practical method of developing custom HPC software
products using a store of libraries and tools independent from the OS called a
"garden". All dependencies from the product to libraries of the underlying OS
distribution are carefully severed, isolating the package from instability due
to system upgrades and ensuring repeatable deterministic builds on different
flavors of Linux. The method also guarantees multiple versions of a software
product may exist together and function correctly, greatly facilitating upgrade
and rollback. The method is the first known system to expose all past software
versions to the designer, and support deterministic single-package rollback
without affecting other installed software. An application of this method for
building a high performance trading system in C++ is presented.


title:
Convergence Analysis of Mixed Timescale Cross-Layer Stochastic
  Optimization

abstract:
  This paper considers a cross-layer optimization problem driven by
multi-timescale stochastic exogenous processes in wireless communication
networks. Due to the hierarchical information structure in a wireless network,
a mixed timescale stochastic iterative algorithm is proposed to track the
time-varying optimal solution of the cross-layer optimization problem, where
the variables are partitioned into short-term controls updated in a faster
timescale, and long-term controls updated in a slower timescale. We focus on
establishing a convergence analysis framework for such multi-timescale
algorithms, which is difficult due to the timescale separation of the algorithm
and the time-varying nature of the exogenous processes. To cope with this
challenge, we model the algorithm dynamics using stochastic differential
equations (SDEs) and show that the study of the algorithm convergence is
equivalent to the study of the stochastic stability of a virtual stochastic
dynamic system (VSDS). Leveraging the techniques of Lyapunov stability, we
derive a sufficient condition for the algorithm stability and a tracking error
bound in terms of the parameters of the multi-timescale exogenous processes.
Based on these results, an adaptive compensation algorithm is proposed to
enhance the tracking performance. Finally, we illustrate the framework by an
application example in wireless heterogeneous network.


title: Spectral dimension of Liouville quantum gravity

abstract:
  This paper is concerned with computing the spectral dimension of 2d-Liouville
quantum gravity. As a warm-up, we first treat the simple case of boundary
Liouville quantum gravity. We prove that the spectral dimension is 1 via an
exact expression for the boundary Liouville Brownian motion and heat kernel.
Then we treat the 2d-case via a decomposition of time integral transforms of
the Liouville heat kernel into Gaussian multiplicative chaos of Brownian
bridges. We show that the spectral dimension is 2 in this case, as announced by
physicists (see Ambj\orn and al. in \cite{amb}) fifteen years ago.


title: DUst Around NEarby Stars. The survey observational results

abstract:
  Debris discs are a consequence of the planet formation process and constitute
the fingerprints of planetesimal systems. Their solar system's counterparts are
the asteroid and Edgeworth-Kuiper belts. The DUNES survey aims at detecting
extra-solar analogues to the Edgeworth-Kuiper belt around solar-type stars,
putting in this way the solar system into context. The survey allows us to
address some questions related to the prevalence and properties of planetesimal
systems. We used {\it Herschel}/PACS to observe a sample of nearby FGK stars.
Data at 100 and 160 $\mu$m were obtained, complemented in some cases with
observations at 70 $\mu$m, and at 250, 350 and 500 $\mu$m using SPIRE. The
observing strategy was to integrate as deep as possible at 100 $\mu$m to detect
the stellar photosphere. Debris discs have been detected at a fractional
luminosity level down to several times that of the Edgeworth-Kuiper belt. The
incidence rate of discs around the DUNES stars is increased from a rate of
$\sim$ 12.1% $\pm$ 5% before \emph{Herschel} to $\sim$ 20.2% $\pm$ 2%. A
significant fraction ($\sim$ 52%) of the discs are resolved, which represents
an enormous step ahead from the previously known resolved discs. Some stars are
associated with faint far-IR excesses attributed to a new class of cold discs.
Although it cannot be excluded that these excesses are produced by coincidental
alignment of background galaxies, statistical arguments suggest that at least
some of them are true debris discs. Some discs display peculiar SEDs with
spectral indexes in the 70-160$\mu$m range steeper than the Rayleigh-Jeans one.
An analysis of the debris disc parameters suggests that a decrease might exist
of the mean black body radius from the F-type to the K-type stars. In addition,
a weak trend is suggested for a correlation of disc sizes and an
anticorrelation of disc temperatures with the stellar age.


title: Geometric Reid's recipe for dimer models

abstract:
  Crepant resolutions of three-dimensional toric Gorenstein singularities are
derived equivalent to noncommutative algebras arising from consistent dimer
models. By choosing a special stability parameter and hence a distinguished
crepant resolution $Y$, this derived equivalence generalises the Fourier-Mukai
transform relating the $G$-Hilbert scheme and the skew group algebra
$\CC[x,y,z]\ast G$ for a finite abelian subgroup of $\SL(3,\CC)$. We show that
this equivalence sends the vertex simples to pure sheaves, except for the zero
vertex which is mapped to the dualising complex of the compact exceptional
locus. This generalises results of Cautis-Logvinenko and Cautis-Craw-Logvinenko
to the dimer setting, though our approach is different in each case. We also
describe some of these pure sheaves explicitly and compute the support of the
remainder, providing a dimer model analogue of results from Logvinenko.


title:
Observation of Time-domain Rabi Oscillations in the Landau-Zener Regime
  with a Single Electronic Spin

abstract:
  Under resonant conditions, a long sequence of landau-zener transitions can
lead to Rabi oscillations. Using a nitrogen-vacancy (NV) center spin in
diamond, we investigated the interference between more than 100 Landau-Zener
processes. We observed the new type of Rabi oscillations of the electron spin
resulting from the interference between successive Landau-Zener processes in
various regimes, including both slow and fast passages. The combination of the
control techniques and the favorable coherent properties of NV centers provides
an excellent experimental platform to study a variety of quantum dynamical
phenomena.


title:
Demonstration of Free-space Reference Frame Independent Quantum Key
  Distribution

abstract:
  Quantum key distribution (QKD) is moving from research laboratories towards
applications. As computing becomes more mobile, cashless as well as cardless
payment solutions are introduced, and a need arises for incorporating QKD in a
mobile device. Handheld devices present a particular challenge as the
orientation and the phase of a qubit will depend on device motion. This problem
is addressed by the reference frame independent (RFI) QKD scheme. The scheme
tolerates an unknown phase between logical states that varies slowly compared
to the rate of particle repetition. Here we experimentally demonstrate the
feasibility of RFI QKD over a free-space link in a prepare and measure scheme
using polarisation encoding. We extend the security analysis of the RFI QKD
scheme to be able to deal with uncalibrated devices and a finite number of
measurements. Together these advances are an important step towards mass
production of handheld QKD devices.