title:
Reinvestigating the Uncovered Interest Rate Parity Puzzle via Analysis
  of Multivariate Tail Dependence in Currency Carry Trades

abstract:
  The currency carry trade is the investment strategy that involves selling low
interest rate currencies in order to purchase higher interest rate currencies,
thus profiting from the interest rate differentials. This is a well known
financial puzzle to explain, since assuming foreign exchange risk is
uninhibited and the markets have rational risk-neutral investors, then one
would not expect profits from such strategies. That is uncovered interest rate
parity (UIP), the parity condition in which exposure to foreign exchange risk,
with unanticipated changes in exchange rates, should result in an outcome that
changes in the exchange rate should offset the potential to profit from such
interest rate differentials. The two primary assumptions required for interest
rate parity are related to capital mobility and perfect substitutability of
domestic and foreign assets. Given foreign exchange market equilibrium, the
interest rate parity condition implies that the expected return on domestic
assets will equal the exchange rate-adjusted expected return on foreign
currency assets.
  However, it has been shown empirically, that investors can actually earn
arbitrage profits by borrowing in a country with a lower interest rate,
exchanging for foreign currency, and investing in a foreign country with a
higher interest rate, whilst allowing for any losses (or gains) from exchanging
back to their domestic currency at maturity. Therefore trading strategies that
aim to exploit the interest rate differentials can be profitable on average.
The intention of this paper is therefore to reinterpret the currency carry
trade puzzle in light of heavy tailed marginal models coupled with multivariate
tail dependence features in the analysis of the risk-reward for the currency
portfolios with high interest rate differentials and low interest rate
differentials.


title: On the computational complexity of Data Flow Analysis

abstract:
  We consider the problem of Data Flow Analysis over monotone data flow
frameworks with a finite lattice. The problem of computing the Maximum Fixed
Point (MFP) solution is shown to be P-complete even when the lattice has just
four elements. This shows that the problem is unlikely to be efficiently
parallelizable. It is also shown that the problem of computing the Meet Over
all Paths (MOP) solution is NL-complete (and hence efficiently parallelizable)
when the lattice is finite even for non-monotone data flow frameworks. These
results appear in contrast with the fact that when the lattice is not finite,
solving the MOP problem is undecidable and hence significantly harder than the
MFP problem which is polynomial time computable for lattices of finite height.


title:
MCNP6 Study of Fragmentation Products from 112Sn + 112Sn and 124Sn +
  124Sn at 1 GeV/nucleon

abstract:
  Isotope production cross sections from 112Sn + 112Sn and 124Sn + 124Sn
reactions at 1 GeV/nucleon, which were measured recently at GSI using the
heavy-ion accelerator SIS18 and the Fragment Separator (FRS), have been
analyzed with the latest Los Alamos Monte-Carlo transport code MCNP6 using the
LAQGSM03.03 event generator. MCNP6 reproduces reasonably well all the measured
cross sections. Comparison of the MCNP6 results with the measured data and with
calculations by a modification of the Los Alamos version of the Quark-Gluon
String Model allowing for multifragmentation processes in the framework of the
Statistical Multifragmentation Model (SMM) by Botvina and coauthors, as
realized in the code LAQGSM03.S1, does not suggest unambiguous evidence of a
multifragmentation signature.


title: Cosmological data and indications for new physics

abstract:
  Data from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope
(SPT), combined with the nine-year data release from the WMAP satellite,
provide very precise measurements of the cosmic microwave background (CMB)
angular anisotropies down to very small angular scales. Augmented with
measurements from Baryonic Acoustic Oscillations surveys and determinations of
the Hubble constant, we investigate whether there are indications for new
physics beyond a Harrison-Zel'dovich model for primordial perturbations and the
standard number of relativistic degrees of freedom at primordial recombination.
All combinations of datasets point to physics beyond the minimal
Harrison-Zel'dovich model in the form of either a scalar spectral index
different from unity or additional relativistic degrees of freedom at
recombination (e.g., additional light neutrinos). Beyond that, the extended
datasets including either ACT or SPT provide very different indications: while
the extended-ACT (eACT) dataset is perfectly consistent with the predictions of
standard slow-roll inflation, the extended-SPT (eSPT) dataset prefers a
non-power-law scalar spectral index with a very large variation with scale of
the spectral index. Both eACT and eSPT favor additional light degrees of
freedom. eACT is consistent with zero neutrino masses, while eSPT favors
nonzero neutrino masses at more than 95% confidence.


title:
Spin squeezing, entanglement and coherence in two driven, dissipative,
  nonlinear cavities coupled with single and two-photon exchange

abstract:
  We investigate spin squeezing, quantum entanglement and second order
coherence in two coupled, driven, dissipative, nonlinear cavities. We compare
these quantum statistical properties for the cavities coupled with either
single or two-photon exchange. Solving the quantum optical master equation of
the system numerically in the steady state, we calculate the zero-time delay
second-order correlation function for the coherence, genuine two-mode
entanglement parameter, and an optimal spin squeezing inequality associated
with particle entanglement. We identify regimes of distinct quantum statistical
character depending on the relative strength of photon-exchange and
nonlinearity. Moreover, we examine the effects of weak and strong drives on
these quantum statistical regimes.


title:
Exterior mass estimates and $L^2$ restriction bounds for Neumann data
  along hypersurfaces

abstract:
  We study the problem of estimating the $L^2$ norm of Laplace eigenfunctions
on a compact Riemannian manifold $M$ when restricted to a hypersurface $H$. We
prove mass estimates for the restrictions of eigenfunctions $\phi_h$, $(h^2
\Delta - 1)\phi_h = 0$, to $H$ in the region exterior to the coball bundle of
$H$, on $h^{\delta}$-scales ($0\leq \delta < 2/3$). We use this estimate to
obtain an $O(1)$ $L^2$-restriction bound for the Neumann data along $H.$ The
estimate also applies to eigenfunctions of semiclassical Schr\"odinger
operators.


title:
Effect of disorder on 2D topological merging transition from a Dirac
  semi-metal to a normal insulator

abstract:
  We study the influence of disorder on the topological transition from a
two-dimensional Dirac semi-metal to an insulating state. This transition is
described as a continuous merging of two Dirac points leading to a semi-Dirac
spectrum at the critical point. The latter is characterized by a dispersion
relation linear in one direction and quadratic in the orthogonal one. Using the
self-consistent Born approximation and renormalization group we calculate the
density of states above, below and in the vicinity of the transition in the
presence of different types of disorder. Beyond the expected disorder smearing
of the transition we find an intermediate disordered semi-Dirac phase. On one
side this phase is separated from the insulating state by a continuous
transition while on the other side it evolves through a crossover to the
disordered Dirac phase.


title:
MCNP6 Simulation of Quasi-Monoenergetic 7Li(p,n) Neutron Sources below
  150 MeV

abstract:
  The applicability of MCNP6 to simulate quasi-monoenergetic neutron sources
from interactions of proton beams with energies below 150 MeV on thick 7Li
targets have been studied. Neutron spectra at zero degrees from a 2-mm 7Li
layer backed by a 12-mm carbon beam stopper in an Al flange bombarded with
protons of 20, 25, 30, 35, and 40 MeV have been calculated with MCNP6 using the
recent Los Alamos data library as well as using the Bertini+Dresner and
CEM03.03 event generators. A comparison with the experimental neutron spectra
shows that the event generators do not do well in describing such reactions,
while MCNP6 using the LANL data library simulates production of neutrons from p
+ 7Li in good agreement with the measured data.


title:
Non-Markovian spin transfer dynamics in magnetic semiconductors despite
  short memory times

abstract:
  A quantum kinetic theory of the spin transfer between carriers and Mn atoms
in a Mn doped diluted magnetic semiconductor is presented. It turns out that
the typical memory time associated with these processes is orders of magnitude
shorter than the time scale of the spin transfer. Nevertheless, Markovian rate
equations, which are obtained by neglecting the memory, work well only for bulk
systems. For quantum wells and wires the quantum kinetic results qualitatively
deviate from the Markovian limit under certain conditions. Instead of a
monotonic decay of an initially prepared excess electron spin, an overshoot or
even coherent oscillations are found. It is demonstrated that these features
are caused by energetic redistributions of the carriers due to the energy-time
uncertainty.


title:
Spectral state evolution of 4U~1820-30: the stability of the spectral
  index of Comptonization tail

abstract:
  We analyze the X-ray spectra and their timing properties of the compact X-ray
binary 4U~1820-30. We establish a number of spectral transitions in this source
seen with BeppoSAX and RXTE. During the RXTE observations (1996 -- 2009), the
source were approximately 75% of its time in the soft state making the lower
banana and upper banana transitions combined with long-term low-high state
transitions. We reveal that all of the X-ray spectra of 4U~1820-30 are fit by a
composition of a thermal (blackbody) component, a Comptonization component
(COMPTB) and a Gaussian-line component. Thus using this spectral analysis we
find that the photon power-law index Gamma of the Comptonization component is
almost unchangeable (Gamma~2) while the electron temperature kT_e changes from
2.9 to 21 keV during these spectral events. We also establish that for these
spectral events the normalization of COMPTB component (which is proportional to
mass accretion rate, \dot M increases by factor 8 when kT_e decreases from 21
keV to 2.9 keV. Before this index stability effect was also found analyzing
X-ray data for Z-source GX 340+0 and for atolls, 4U~1728-34, GX~3+1. Thus, we
can suggest that this spectral stability property is a spectral signature of an
accreting neutron star source. On the other hand in a black hole binary Gamma
monotonically increases with \dot M and ultimately its value saturates at large
\dot M.


title: About Inverse 3-SAT

abstract:
  The Inverse 3-SAT problem is known to be coNP Complete. This article shows a
new interesting way to solve directly the problem by using closure under
resolution and partial assignment properties. An algorithm is proposed which
lets solve the (co)Inverse 3-SAT problem.


title: Contagions in Random Networks with Overlapping Communities

abstract:
  We consider a threshold epidemic model on a clustered random graph with
overlapping communities. In other words, our epidemic model is such that an
individual becomes infected as soon as the proportion of her infected neighbors
exceeds the threshold q of the epidemic. In our random graph model, each
individual can belong to several communities. The distributions for the
community sizes and the number of communities an individual belongs to are
arbitrary.
  We consider the case where the epidemic starts from a single individual, and
we prove a phase transition (when the parameter q of the model varies) for the
appearance of a cascade, i.e. when the epidemic can be propagated to an
infinite part of the population. More precisely, we show that our epidemic is
entirely described by a multi-type (and alternating) branching process, and
then we apply Sevastyanov's theorem about the phase transition of multi-type
Galton-Watson branching processes. In addition, we compute the entries of the
matrix whose largest eigenvalue gives the phase transition.


title:
Unambiguous Identification of the Second 2+ State in 12C and the
  Structure of the Hoyle State

abstract:
  The second 2+ state of 12C, predicted over fifty years ago as an excitation
of the Hoyle state, has been unambiguously identified using the 12C(g,a_0)8Be
reaction. The alpha particles produced by the photodisintegration of 12C were
detected using an Optical Time Projection Chamber (O-TPC). Data were collected
at beam energies between 9.1 and 10.7 MeV using the intense nearly
mono-energetic gamma-ray beams at the HIgS facility. The measured angular
distributions determine the cross section and the E1-E2 relative phases as a
function of energy leading to an unambiguous identification of the second 2+
state in 12C at 10.03(11) MeV, with a total width of 800(130) keV and a ground
state gamma-decay width of 60(10) meV; B(E2: 2+ ---> gs) = 0.73(13) e2fm4 [or
0.45(8) W.u.]. The Hoyle state and its rotational 2+ state that are more
extended than the ground state of 12C presents a challenge and constraints for
models attempting to reveal the nature of three alpha particle states in 12C.
Specifically it challenges the ab-initio Lattice Effective Field Theory (L-EFT)
calculations that predict similar r.m.s. radii for the ground state and the
Hoyle state.

categories: nucl-ex astro-ph.SR nucl-th physics.ins-det


title: Homogeneous division polynomials for Weierstrass elliptic curves

abstract:
  Starting from the classical division polynomials we construct homogeneous
polynomials $\alpha_n$, $\beta_n$, $\gamma_n$ such that for $P = (x:y:z)$ on an
elliptic curve in Weierstrass form over an arbitrary ring we have $nP =
\bigl(\alpha_n(P):\beta_n(P):\gamma_n(P)\bigr)$. To show that
$\alpha_n,\beta_n,\gamma_n$ indeed have this property we use the a priori
existence of such polynomials, which we deduce from the Theorem of the Cube.
  We then use this result to show that the equations defining the modular curve
$Y_1(n)_{\mathbb C}$ computed for example by Baaziz, in fact are equations of
$Y_1(n)$ over $\mathbb Z[1/n]$.


title: Topology of angle valued maps, bar codes and Jordan blocks

abstract:
  In this paper one presents a collection of results about the "bar codes" and
"Jordan blocks" introduced by Burghelea-Day as "computer friendly" invariants
of a tame angle-valued map and one relates these invariants to the Betti
numbers, Novikov Betti numbers and the monodromy of the underlying space and
map.
  Among others, one organizes the bar codes as two configurations of points in
C\0 and one establishes their main properties: stability property and when the
underlying space is a closed topological manifold, Poincar\'e duality property.
One also provides an alternative "computer friendly" definition of the
monodromy of an angle valued map based on the algebra of linear relations as
well as a refinement of Morse and Morse-Novikov inequalities.


title:
Uniformity of multiplicative functions and partition regularity of some
  quadratic equations

abstract:
  Since the theorems of Schur and van der Waerden, numerous partition
regularity results have been proved for linear equations, but progress has been
scarce for non-linear ones, the hardest case being equations in three
variables. We prove partition regularity for certain equations involving forms
in three variables, showing for example that the equations $16x^2+9y^2=n^2$ and
$x^2+y^2-xy=n^2$ are partition regular, where $n$ is allowed to vary freely in
$\mathbb{N}$. For each such problem we establish a density analogue that can be
formulated in ergodic terms as a recurrence property for actions by dilations
on a probability space. Our key tool for establishing such recurrence
properties is a decomposition result for multiplicative functions which is of
independent interest. Roughly speaking, it states that the arbitrary
multiplicative function of modulus 1 can be decomposed into two terms, one that
is approximately periodic and another that has small Gowers uniformity norm of
degree three.


title: Cosmological constraints on Brans-Dicke theory

abstract:
  We report strong cosmological constraints on the Brans-Dicke (BD) theory of
gravity using Cosmic Microwave Background data from Planck.We consider two
types of models. First, the initial condition of the scalar field is fixed to
give the same effective gravitational strength $G_{eff}$ today as the one
measured on the Earth, $G_N$. In this case the BD parameter $\omega$ is
constrained to $\omega > 692$ at the $99\%$ confidence level, an order of
magnitude improvement over previous constraints.In the second type the initial
condition for the scalar is a free parameter leading to a somewhat stronger
constraint of $\omega > 890$ while $G_{eff}$ is constrained to $0.981
<\frac{G_{eff}}{G_N} <1.285$ at the same confidence level. We argue that these
constraints have greater validity than for the BD theory and are valid for any
Horndeski theory, the most general second-order scalar-tensor theory, which
approximates BD on cosmological scales. In this sense, our constraints place
strong limits on possible modifications of gravity that might explain cosmic
acceleration.


title: Non-Hermitian star-shaped quantum graphs

abstract:
  A compact review is given, and a few new numerical results are added to the
recent studies of the q-pointed one-dimensional star-shaped quantum graphs.
These graphs are assumed endowed with certain specific, manifestly
non-Hermitian point interactions, localized either in the inner vertex or in
all of the outer vertices and carrying, in the latter case, an interesting
zero-inflow interpretation.


title: Tau neutrino as a probe of nonstandard interaction

abstract:
  We study the $\Delta$-resonance and deep inelastic scattering contributions
in the tau-neutrino nucleon scattering $\nu_{\tau}+ N \to \tau^- + X$ and
$\bar{\nu}_{\tau}+ N \to \tau^+ + X$ in the presence of a charged Higgs and a
$W'$ gauge boson. The new physics effects to the quasielastic process have been
discussed in a previous work. The extractions of the atmospheric mixing angle
$\theta_{23}$ rely on the standard model cross sections for $\nu_{\tau}+ N \to
\tau^- + X$ in $\nu_{\tau}$ appearance experiments. Corrections to the cross
sections from the charged Higgs and $W'$ contributions modify the measured
mixing angle. We include form factor effects in the new physics calculations
and find the deviations of the mixing angle. If high-energy Long Base Line
experiments are designed to measure $\theta_{13}$ through tau neutrino
appearance, the new physics effects to $\nu_{\tau}+ N \to \tau^- + X$ and
$\bar{\nu}_{\tau}+ N \to \tau^+ + X$ can impact the extraction of this mixing
angle. Finally, we investigate the new physics effects on the polarization of
the $\tau^\mp$ leptons produced in $\nu_\tau (\bar{\nu}_\tau)$ nucleon
scattering.


title:
Enhanced quasiparticle dynamics of quantum well states: the giant Rashba
  system BiTeI and topological insulators

abstract:
  In the giant Rashba semiconductor BiTeI electronic surface scattering with
Lorentzian linewidth is observed that shows a strong dependence on surface
termination and surface potential shifts. A comparison with the topological
insulator Bi2Se3 evidences that surface confined quantum well states are the
origin of these processes. We notice an enhanced quasiparticle dynamics of
these states with scattering rates that are comparable to polaronic systems in
the collision dominated regime. The Eg symmetry of the Lorentzian scattering
contribution is different from the chiral (RL) symmetry of the corresponding
signal in the topological insulator although both systems have spin-split
surface states.


title:
Acceleration of Energetic Particles Through Self-Generated Waves in a
  Decelerating Coronal Shock

abstract:
  We have developed a simulation model of particle acceleration in coronal
shock waves. The model is based on a Monte Carlo method, where particles are
traced in prescribed large-scale electromagnetic fields utilizing the guiding
center approximation. The particles are scattered in the turbulence according
to quasilinear theory, with the scattering amplitude directly proportional to
the intensity of Alfv\'en waves at gyro-resonant wavenumbers. The Alfv\'en
waves are traced simultaneously with the particles, so that the wave field is
propagated outwards from the Sun using WKB propagation supplemented with a
phenomenological wavenumber diffusion term and a growth rate computed from the
net flux of the accelerated particles. We consider initial wave amplitudes
small enough to allow rapid escape of particles from the shock to the ambient
medium. Thus, in our model the Alfv\'en waves responsible for the diffusive
acceleration of particles are generated by the accelerated particles
themselves. In this work, we study the effects of non-constant shock velocity
and non-monotonic Alfv\'en velocity on particle acceleration scenarios. We
report in particular how the deceleration of a shock affects particle intensity
and turbulence power evolution in the vicinity of the shock.


title: A refined Beilinson-Bloch conjecture for motives of modular forms

abstract:
  We propose a refined version of the Beilinson-Bloch conjecture for the motive
associated with a modular form of even weight. This conjecture relates the
dimension of the image of the relevant p-adic Abel-Jacobi map to certain
combinations of Heegner cycles on Kuga-Sato varieties. We prove theorems in the
direction of the conjecture and, in doing so, obtain higher weight analogues of
results for elliptic curves due to Darmon.


title: Supersaturation in the Boolean lattice

abstract:
  We prove a "supersaturation-type" extension of both Sperner's Theorem (1928)
and its generalization by Erdos (1945) to k-chains. Our result implies that a
largest family whose size is x more than the size of a largest k-chain free
family and that contains the minimum number of k-chains is the family formed by
taking the middle (k-1) rows of the Boolean lattice and x elements from the
k-th middle row. We prove our result using the symmetric chain decomposition
method of de Bruijn, van Ebbenhorst Tengbergen, and Kruyswijk (1951).


title: On the Properties of Exact Solutions Endowed with Negative Mass

abstract:
  It is shown that various pathological properties of spacetimes can be
explained by the presence of negative mass, including the cases when the total
mass of the solution is a positive quantity. As an illustration, we consider
several well-known stationary axisymmetric vacuum and electrovac solutions of
the Einstein-Maxwell equations. Our investigation naturally leads to a critique
of the known maximal extensions of the Kerr and Kerr-Newman spacetimes which
turn out to be neither analytic nor physically meaningful.


title: Assembly line worker integration and balancing problem

abstract:
  We propose the Assembly Line Worker Integration and Balancing Problem
(ALWIBP), a new assembly line balancing problem arising in lines with
conventional and disabled workers. The goal of this problem is to maintain high
productivity levels by minimizing the number of workstations needed to reach a
given output, while integrating in the assembly line a number of disabled
workers. Being able to efficiently manage a heterogeneous workforce is
especially important in the current social context where companies are urged to
integrate disabled workers. In this paper we present mathematical models and
heuristics that can help assembly line managers to cope with this additional
complexity; demonstrating by means of a robust benchmark how this integration
can be done with losses of productivity that are much lower than expected.


title:
Interactions in Electronic Mach-Zehnder Interferometers with
  Copropagating Edge Channels

abstract:
  We study Coulomb interactions in the finite bias response of Mach-Zehnder
interferometers, which exploit copropagating edge states in the integer quantum
Hall effect. Here, interactions are particularly important since the coherent
coupling of edge channels is due to a resonant mechanism that is spoiled by
inelastic processes. We find that interactions yield a saturation, as a
function of bias voltage, of the period-averaged interferometer current, which
gives rise to unusual features, such as negative differential conductance,
enhancement of the visibility of the current, and nonbounded or even diverging
visibility of the differential conductance.


title: Heavy-ion Acceleration and Self-generated Waves in Coronal Shocks

abstract:
  Context: Acceleration in coronal mass ejection driven shocks is currently
considered the primary source of large solar energetic particle events.
  Aims: The solar wind, which feeds shock-accelerated particles, includes
numerous ion populations, which offer much insight into acceleration processes.
We present first simulations of shock-accelerated minor ions, in order to
explore trapping dynamics and acceleration timescales in detail.
  Methods: We have simulated diffusive shock acceleration of minor ions (3He2+,
4He2+, 16O6+ and 56Fe14+) and protons using a Monte Carlo method, where
self-generated Alfv\'enic turbulence allows for repeated shock crossings and
acceleration to high energies.
  Results: We present the effect of minor ions on wave generation, especially
at low wavenumbers, and show that it is significant. We find that maximum ion
energy is determined by the competing effects of particle escape due to
focusing in an expanding flux tube and trapping due to the amplified
turbulence. We show the dependence of cut-off energy on the particle charge to
mass ratio to be approximately (Q/A)^1.5.
  Conclusions: We suggest that understanding the acceleration of minor ions at
coronal shocks requires simulations which allow us to explore trapping dynamics
and acceleration timescales in detail, including evolution of the turbulent
trapping boundary. We conclude that steady-state models do not adequately
describe the acceleration of heavy ions in coronal shocks.


title: Totally real pencils of cubics with respect to sextics

abstract:
  A real algebraic plane curve $A$ is said to be dividing if its real part
$\mathbb{R}A$ disconnects its complex part $\mathbb{C}A$. A pencil of curves is
totally real with respect to $A$ if it has only real intersections with
$\mathbb{C}A$. If there exists such a pencil, then $A$ is dividing, this is the
case for the $M$-curves. Can conversely any dividing curve be endowed with a
totally real pencil? We study here the case of $M-2$-sextics having 2 or 6
empty exterior ovals. Such sextics are always dividing. We prove that they may
actually be endowed with a totally real pencil of cubics.


title: Gaps in the GD-1 Star Stream

abstract:
  GD-1 is a long, thin, Milky Way star stream that has readily visible density
variations along its length. We quantify the locations, sizes and statistical
significance of the density structure, i.e. gaps, using a set of scaled
filters. The shapes of the filters are based on the gaps that develop in
simulations of dark matter sub-halos crossing a star stream. The high Galactic
latitude 8.4 kpc long segment of GD-1 that we examine has 8+/-3 gaps of 99%
significance or greater, with the error estimated on the basis of tests of the
gap-filtering technique. The cumulative distribution of gaps more than 3 times
the width of the stream is in good agreement with predictions for dark matter
sub-halo encounters with cold star streams. The number of gaps narrower than 3
times the width of the GD-1 stream falls well below the cold stream prediction
which is taken into account for the gap creation rate integrated over all
sizes. Simple warm stream simulations scaled to GD-1 show that the falloff in
gaps is expected for sub-halos below a mass of 10^6 M_sun. The GD-1 gaps
requires 100 sub-halos >10^6 M_sun within 30 kpc, the apocenter of GD-1 orbit.
These results are consistent with LCDM sub-halo predictions but further
improvements in stream signal-to-noise and gap modeling will be welcome.


title: The Dynamics of Massive Starless Cores with ALMA

abstract:
  How do stars that are more massive than the Sun form, and thus how is the
stellar initial mass function (IMF) established? Such intermediate- and
high-mass stars may be born from relatively massive pre-stellar gas cores,
which are more massive than the thermal Jeans mass. The Turbulent Core
Accretion model invokes such cores as being in approximate virial equilibrium
and in approximate pressure equilibrium with their surrounding clump medium.
Their internal pressure is provided by a combination of turbulence and magnetic
fields. Alternatively, the Competitive Accretion model requires strongly
sub-virial initial conditions that then lead to extensive fragmentation to the
thermal Jeans scale, with intermediate- and high-mass stars later forming by
competitive Bondi-Hoyle accretion. To test these models, we have identified
four prime examples of massive (~100Msun) clumps from mid-infrared extinction
mapping of infrared dark clouds (IRDCs). Fontani et al. found high deuteration
fractions of N2H+ in these objects, which are consistent with them being
starless. Here we present ALMA observations of these four clumps that probe the
N2D+(3-2) line at 2.3" resolution. We find six N2D+ cores and determine their
dynamical state. Their observed velocity dispersions and sizes are broadly
consistent with the predictions of the Turbulent Core model of
self-gravitating, magnetized (with Alfven Mach number m_A~1) and virialized
cores that are bounded by the high pressures of their surrounding clumps.
However, in the most massive cores, with masses up to ~60Msun, our results
suggest that moderately enhanced magnetic fields (so that m_A~0.3) may be
needed for the structures to be in virial and pressure equilibrium.
Magnetically regulated core formation may thus be important in controlling the
formation of massive cores, inhibiting their fragmentation, and thus helping to
establish the stellar IMF.


title:
Discrete torsion, de Sitter tunneling vacua and AdS brane: U(1) gauge
  theory on D4-brane and an effective curvature

abstract:
  The U(1) gauge dynamics on a D4-brane is revisited, with a two form, to
construct an effective curvature theory in a second order formalism. We exploit
the local degrees in a two form, and modify its dynamics in a gauge invariant
way, to incorporate a non-perturbative metric fluctuation in an effective
D4-brane. Interestingly, the near horizon D4-brane is shown to describe an
asymptotic Anti de Sitter (AdS) in a semi-classical regime. Using Weyl
scaling(s), we obtain the emergent rotating geometries leading to primordial de
Sitter (dS) and AdS vacua in a quantum regime. Under a discrete transformation,
we re-arrange the mixed dS patches to describe a Schwazschild-like dS (SdS) and
a topological-like dS (TdS) black holes. We analyze SdS vacuum for Hawking
radiations to arrive at Nariai geometry, where a discrete torsion forms a
condensate. We perform thermal analysis to identify Nariai vacuum with a TdS.
Investigation reveals an AdS patch within a thermal dS brane, which may provide
a clue to unfold dS/CFT. In addition, the role of dark energy, sourced by a
discrete torsion, in the dS vacua is investigated using Painleve geometries. It
is argued that a D-instanton pair is created by a discrete torsion, with a Big
Bang/Crunch, at the past horizon in a pure dS. Nucleation, of brane/anti-brane
pair(s), is qualitatively analyzed to construct an effective space-time on a
D4-brane and its anti brane. Analysis re-assures the significant role played by
a non-zero mode, of NS-NS two form, to generalize the notion of branes within a
brane.

categories: hep-th astro-ph.CO gr-qc hep-ph math-ph math.MP


title:
A Sufficient Condition for the Existence of a Principal Eigenvalue for
  Nonlocal Diffusion Equations with Applications

abstract:
  Considerable work has gone into studying the properties of nonlocal diffusion
equations. The existence of a principal eigenvalue has been a significant
portion of this work. While there are good results for the existence of a
principal eigenvalue equations on a bounded domain, few results exist for
unbounded domains. On bounded domains, the Krein-Rutman theorem on Banach
spaces is a common tool for showing existence. This article shows that
generalized Krein-Rutman can be used on unbounded domains and that the theory
of positive operators can serve as a powerful tool in the analysis of nonlocal
diffusion equations. In particular, a useful sufficient condition for the
existence of a principal eigenvalue is given.


title: l-facial edge colorings of graphs

abstract:
  An l-facial edge coloring of a plane graph is a coloring of the edges such
that any two edges at distance at most l on a boundary walk of some face
receive distinct colors. It is conjectured that 3l + 1 colors suffice for an
l-facial edge coloring of any plane graph. We prove that 7 colors suffice for a
2-facial edge coloring of any plane graph and therefore confirm the conjecture
for l = 2.


title: Maximizing the Lifetime of Multi-chain PEGASIS using Sink Mobility

abstract:
  In this paper, we propose the mobility of a sink in improved energy efficient
PEGASIS-based protocol (IEEPB) to advance the network lifetime of Wireless
Sensor Networks (WSNs). The multi-head chain, multi-chain concept and the sink
mobility affects largely in enhancing the network lifetime of wireless sensors.
Thus, we recommend Mobile sink improved energy-efficient PEGASIS-based routing
protocol (MIEEPB); a multi-chain model having a sink mobility, to achieve
proficient energy utilization of wireless sensors. As the motorized movement of
mobile sink is steered by petrol or current, there is a need to confine this
movement within boundaries and the trajectory of mobile sink should be fixed.
In our technique, the mobile sink moves along its trajectory and stays for a
sojourn time at sojourn location to guarantee complete data collection. We
develop an algorithm for trajectory of mobile sink. We ultimately perform
wide-ranging experiments to assess the performance of the proposed method. The
results reveal that the proposed way out is nearly optimal and also better than
IEEPB in terms of network lifetime.


title: Near Minimax Line Spectral Estimation

abstract:
  This paper establishes a nearly optimal algorithm for estimating the
frequencies and amplitudes of a mixture of sinusoids from noisy equispaced
samples. We derive our algorithm by viewing line spectral estimation as a
sparse recovery problem with a continuous, infinite dictionary. We show how to
compute the estimator via semidefinite programming and provide guarantees on
its mean-square error rate. We derive a complementary minimax lower bound on
this estimation rate, demonstrating that our approach nearly achieves the best
possible estimation error. Furthermore, we establish bounds on how well our
estimator localizes the frequencies in the signal, showing that the
localization error tends to zero as the number of samples grows. We verify our
theoretical results in an array of numerical experiments, demonstrating that
the semidefinite programming approach outperforms two classical spectral
estimation techniques.


title: Finding all Convex Cuts of a Plane Graph in Polynomial Time

abstract:
  Convexity is a notion that has been defined for subsets of $\RR^n$ and for
subsets of general graphs. A convex cut of a graph $G=(V, E)$ is a
$2$-partition $V_1 \dot{\cup} V_2=V$ such that both $V_1$ and $V_2$ are convex,
\ie shortest paths between vertices in $V_i$ never leave $V_i$, $i \in \{1,
2\}$. Finding convex cuts is $\mathcal{NP}$-hard for general graphs. To
characterize convex cuts, we employ the Djokovic relation, a reflexive and
symmetric relation on the edges of a graph that is based on shortest paths
between the edges' end vertices.
  It is known for a long time that, if $G$ is bipartite and the Djokovic
relation is transitive on $G$, \ie $G$ is a partial cube, then the cut-sets of
$G$'s convex cuts are precisely the equivalence classes of the Djokovic
relation. In particular, any edge of $G$ is contained in the cut-set of exactly
one convex cut. We first characterize a class of plane graphs that we call {\em
well-arranged}. These graphs are not necessarily partial cubes, but any edge of
a well-arranged graph is contained in the cut-set(s) of at least one convex
cut. We also present an algorithm that uses the Djokovic relation for computing
all convex cuts of a (not necessarily plane) bipartite graph in $\bigO(|E|^3)$
time. Specifically, a cut-set is the cut-set of a convex cut if and only if the
Djokovic relation holds for any pair of edges in the cut-set.
  We then characterize the cut-sets of the convex cuts of a general graph $H$
using two binary relations on edges: (i) the Djokovic relation on the edges of
a subdivision of $H$, where any edge of $H$ is subdivided into exactly two
edges and (ii) a relation on the edges of $H$ itself that is not the Djokovic
relation. Finally, we use this characterization to present the first algorithm
for finding all convex cuts of a plane graph in polynomial time.


title: Disformal invariance of Maxwell's field equations

abstract:
  We show that Maxwell's electrodynamics in vacuum is invariant under active
transformations of the metric. These metrics are related by disformal mappings
induced by derivatives of the gauge vector $A_{\mu}$ such that the gauge
symmetry is preserved. Our results generalize the well known conformal
invariance of electrodynamics and characterize a new type of internal symmetry
of the theory. The group structure associated with these transformations is
also investigated in details.


title: Are random trading strategies more successful than technical ones?

abstract:
  In this paper we explore the specific role of randomness in financial
markets, inspired by the beneficial role of noise in many physical systems and
in previous applications to complex socio- economic systems. After a short
introduction, we study the performance of some of the most used trading
strategies in predicting the dynamics of financial markets for different
international stock exchange indexes, with the goal of comparing them with the
performance of a completely random strategy. In this respect, historical data
for FTSE-UK, FTSE-MIB, DAX, and S&P500 indexes are taken into account for a
period of about 15-20 years (since their creation until today).


title: Optimal DoF Region of the Two-User MISO-BC with General Alternating CSIT

abstract:
  In the setting of the time-selective two-user multiple-input single-output
(MISO) broadcast channel (BC), recent work by Tandon et al. considered the case
where - in the presence of error-free delayed channel state information at the
transmitter (delayed CSIT) - the current CSIT for the channel of user 1 and of
user 2, alternate between the two extreme states of perfect current CSIT and of
no current CSIT.
  Motivated by the problem of having limited-capacity feedback links which may
not allow for perfect CSIT, as well as by the need to utilize any available
partial CSIT, we here deviate from this `all-or-nothing' approach and proceed -
again in the presence of error-free delayed CSIT - to consider the general
setting where current CSIT now alternates between any two qualities.
Specifically for $I_1$ and $I_2$ denoting the high-SNR asymptotic
rates-of-decay of the mean-square error of the CSIT estimates for the channel
of user~1 and of user~2 respectively, we consider the case where $I_1,I_2
\in\{\gamma,\alpha\}$ for any two positive current-CSIT quality exponents
$\gamma,\alpha$. In a fast-fading setting where we consider communication over
any number of coherence periods, and where each CSIT state $I_1I_2$ is present
for a fraction $\lambda_{I_1I_2}$ of this total duration, we focus on the
symmetric case of $\lambda_{\alpha\gamma}=\lambda_{\gamma\alpha}$, and derive
the optimal degrees-of-freedom (DoF) region. The result, which is supported by
novel communication protocols, naturally incorporates the aforementioned
`Perfect current' vs. `No current' setting by limiting $I_1,I_2\in\{0,1\}$.
  Finally, motivated by recent interest in frequency correlated channels with
unmatched CSIT, we also analyze the setting where there is no delayed CSIT.


title: New Constraints On The Dark Energy Equation of State

abstract:
  We combine recent measurements of Cosmic Microwave Background Anisotropies,
Supernovae luminosity distances and Baryonic Acoustic Oscillations to derive
constraints on the dark energy equation of state w in the redshift range 0<z<2,
using a principal components approach. We find no significant deviations from
the expectations of a cosmological constant. However, combining the datasets we
find slight indication for w<-1 at low redshift, thus highlighting how these
datasets prefer a non-constant w. Nevertheless the cosmological constant is
still in agreement with these observations, while we find that some classes of
alternative models may be in tension with the inferred w(z) behaviour.


title:
Nonlinear resonances with a potential: Multilinear estimates and an
  application to NLS

abstract:
  This paper considers the question of global in time existence and asymptotic
behavior of small-data solutions of nonlinear dispersive equations with a real
potential $V$. The main concern is treating nonlinearities whose degree is low
enough as to preclude the simple use of classical energy methods and decay
estimates. In their place, we present a systematic approach that adapts the
space-time resonance method to the non-Euclidean setting using the spectral
theory of the Schroedinger operator $-\Delta+V$. We start by developing tools
of independent interest, namely multilinear analysis (Coifman-Meyer type
theorems) in the framework of the corresponding distorted Fourier transform. As
a first application, this is then used to prove global existence and scattering
for a quadratic Schroedinger equation.


title:
A Model for Incorporating Computation Without Changing the Course: An
  example from middle-division classical mechanics

abstract:
  Much of the research done by modern physicists would be impossible without
the use of computation. And yet, while computation is a crucial tool of
practicing physicists, physics curricula do not generally reflect its
importance and utility. To more tightly connect undergraduate preparation with
professional practice, we integrated computational instruction into
middle-division classical mechanics at the University of Colorado Boulder. Our
model for integration works within the constraints of faculty who do not
specialize in computation teaching standard physics courses by placing a strong
emphasis on {an adaptable curriculum}. Our model includes the construction of
computational learning goals, the design of computational activities consistent
with those goals, and the assessment of students' computational fluency. We
present critiques of our model as we work to develop an effective and
sustainable model for computational instruction in the undergraduate curriculum


title: Mutual information in interacting spin systems

abstract:
  This thesis uses a quantity that is defined and justified by information
theory -- mutual information -- to examine models of condensed matter systems.
More precisely, it studies models which are made up out of ferromagnetically
interacting spins. Quantum information theory often focuses on the ground state
of such systems; we will however be interested in what happens at finite
temperature.
  Using mutual information, which can be seen as a generalization of
entanglement entropy to the finite-temperature case, we can study the different
phases occurring in these models, and in particular the phase transitions
between those. We examine broadly two different classes of models: classical
spins on two-dimensional lattices, and fully-connected models of
quantum-mechanical spin-1/2 particles.
  (Abstract abridged.)


title: Quantum Correlations are Tightly Bound by the Exclusivity Principle

abstract:
  It is a fundamental problem in physics of what principle limits the
correlations as predicted by our current description of nature, based on
quantum mechanics. One possible explanation is the "global exclusivity"
principle recently discussed in Phys. Rev. Lett. 110, 060402 (2013). In this
work we show that this principle actually has a much stronger restriction on
the probability distribution. We provide a tight constraint inequality imposed
by this principle and prove that this principle singles out quantum
correlations in scenarios represented by any graph. Our result implies that the
exclusivity principle might be one of the fundamental principles of nature.


title:
Generic properties of the spectrum of the Stokes system with Dirichlet
  boundary condition in R^3

abstract:
  Let (SD_\Omega) be the Stokes operator defined in a bounded domain \Omega of
R^3 with Dirichlet boundary conditions. We prove that, generically with respect
to the domain \Omega with C^5 boundary, the spectrum of (SD_\Omega) satisfies a
non resonant property introduced by C. Foias and J. C. Saut to linearize the
Navier-Stokes system in a bounded domain \Omega of R^3 with Dirichlet boundary
conditions. For that purpose, we first prove that, generically with respect to
the domain \Omega with C^5 boundary, all the eigenvalues of (SD_\Omega) are
simple. That answers positively a question raised by J. H. Ortega and E.
Zuazua. The proofs of these results follow a standard strategy based on a
contradiction argument requiring shape differentiation. One needs to shape
differentiate at least twice the initial problem in the direction of carefully
chosen domain variations. The main step of the contradiction argument amounts
to study the evaluation of Dirichlet-to-Neumann operators associated to these
domain variations.


title: On tangents to curves

abstract:
  In this paper, we give a simple definition of tangents to a curve in
elementary geometry. From which, we characterize the existence of the tangent
to a curve at a point.


title:
Local properties of patterned vegetation: quantifying endogenous and
  exogenous effects

abstract:
  Dryland ecosystems commonly exhibit periodic bands of vegetation, thought to
form due to competition between individual plants for heterogeneously
distributed water. In this paper, we develop a Fourier method for locally
identifying the pattern wavenumber and orientation, and apply it to aerial
images from a region of vegetation patterning near Fort Stockton, Texas. We
find that the local pattern wavelength and orientation are typically coherent,
but exhibit both rapid and gradual variation driven by changes in hillslope
gradient and orientation, the potential for water accumulation, or soil type.
Endogenous pattern dynamics, when simulated for spatially homogeneous
topographic and vegetation conditions, predict pattern properties that are much
less variable than the orientation and wavelength observed in natural systems.
Our local pattern analysis, combined with ancillary datasets describing soil
and topographic variation, highlights a largely unexplored correlation between
soil depth, pattern coherence, vegetation cover and pattern wavelength. It
also, surprisingly, suggests that downslope accumulation of water may play a
role in changing vegetation pattern properties.


title:
Self-Replicating Three-Dimensional Vortices in Neutrally-Stable
  Stratified Rotating Shear Flows

abstract:
  A previously unknown instability creates space-filling lattices of 3D
vortices in linearly-stable, rotating, stratified shear flows. The instability
starts from an easily-excited critical layer. The layer intensifies by drawing
energy from the background shear and rolls-up into vortices that excite new
critical layers and vortices. The vortices self-similarly replicate to create
lattices of turbulent vortices. The vortices persist for all time. This
self-replication occurs in stratified Couette flows and in the dead zones of
protoplanetary disks where it can de-stabilize Keplerian flows.

categories: astro-ph.EP astro-ph.GA astro-ph.SR nlin.CD physics.flu-dyn


title: Dark Energy and Dark Matter Models: leading to the fifth force

abstract:
  We revisit the problems of dark energy and dark matter and several models
designed to explain them, leading to the hypothetical fifth force in the light
of some latest findings.


title: Holography, Dark Energy and Entropy of Large Cosmic Structures

abstract:
  As is well known, black hole entropy is proportional to the area of the
horizon suggesting a holographic principle wherein all degrees of freedom
contributing to the entropy reside on the surface. In this note, we point out
that large scale dark energy (such as a cosmological constant) constraining
cosmic structures can imply a similar situation for the entropy of a hierarchy
of such objects.


title: Higgs self-coupling beta-function in the Standard Model at three loops

abstract:
  We present the results for three-loop beta-function for the Higgs
self-coupling calculated within the unbroken phase of the Standard Model. We
also provide the expression for three-loop beta-function of the Higgs mass
parameter, which is obtained as a by-product of our main calculation. Our
results coincide with that of recent paper arXiv:1303.2890. In addition, the
expression for the Higgs field anomalous dimension is given.


title:
Liquid Hole-Multipliers: A potential concept for large single-phase
  noble-liquid TPCs of rare events

abstract:
  A novel concept is proposed for large-volume single-phase noble-liquid TPC
detectors for rare events. Both radiation-induced scintillation-light and
ionization-charge are detected by Liquid Hole-Multipliers, LHM, immersed in the
noble liquid. The latter may consist of cascaded Gas Electron Multipliers
(GEM), Thick Gas Electron Multiplier (THGEM) electrodes or others, coated with
CsI UV-photocathodes. Electrons, photo-induced on CsI by primary scintillation
in the noble liquid, and event-correlated drifting ionization electrons are
amplified in the cascaded elements primarily through electroluminescence, and
possibly through additional moderate avalanche, occurring within the holes. The
resulting charge-signals or light-pulses are recorded on anode pads or with
photosensors, e.g. gaseous photomultipliers (GPM), respectively. Potential
affordable solutions are proposed for multi-ton dark-matter detectors; open
questions are formulated for validating this dream.


title:
Group-Based Trajectory Modeling of Citations in Scholarly Literature:
  Dynamic Qualities of "Transient" and "Sticky Knowledge Claims"

abstract:
  Group-based Trajectory Modeling (GBTM) is applied to the citation curves of
articles in six journals and to all citable items in a single field of science
(Virology, 24 journals), in order to distinguish among the developmental
trajectories in subpopulations. Can highly-cited citation patterns be
distinguished in an early phase as "fast-breaking" papers? Can "late bloomers"
or "sleeping beauties" be identified? Most interesting, we find differences
between "sticky knowledge claims" that continue to be cited more than ten years
after publication, and "transient knowledge claims" that show a decay pattern
after reaching a peak within a few years. Only papers following the trajectory
of a "sticky knowledge claim" can be expected to have a sustained impact. These
findings raise questions about indicators of "excellence" that use aggregated
citation rates after two or three years (e.g., impact factors). Because
aggregated citation curves can also be composites of the two patterns,
5th-order polynomials (with four bending points) are needed to capture citation
curves precisely. For the journals under study, the most frequently cited
groups were furthermore much smaller than ten percent. Although GBTM has proved
a useful method for investigating differences among citation trajectories, the
methodology does not enable us to define a percentage of highly-cited papers
inductively across different fields and journals. Using multinomial logistic
regression, we conclude that predictor variables such as journal names, number
of authors, etc., do not affect the stickiness of knowledge claims in terms of
citations, but only the levels of aggregated citations (that are
field-specific).


title:
Wigner rotations and an apparent paradox in relativistic quantum
  information

abstract:
  It is shown that a general model for particle detection in combination with a
linear application of the Wigner rotations, which correspond to
momentum-dependent changes of the particle spin under Lorentz transformations,
to the state of a massive relativistic particle in a superposition of two
counter-propagating momentum states leads to a paradox. The paradoxical
behavior is that the probability of finding the particle at different positions
would depend on the reference frame. A solution to the paradox is given when
the physical construction of the corresponding state is taken into account,
suggesting that we cannot in general linearly apply the Wigner rotations to a
quantum state without considering the appropriate physical interpretation.


title: Large Scale Anisotropic Bias from Primordial non-Gaussianity

abstract:
  In this work we study the large scale structure bias in models of anisotropic
inflation. We use the Peak Background Splitting method in Excursion Set Theory
to find the scale-dependent bias. We show that the amplitude of the bias is
modified by a direction- dependent factor. In the specific anisotropic
inflation model which we study, the scale- dependent bias vanishes at leading
order when the long wavelength mode in squeezed limit is aligned with the
anisotropic direction in the sky. We also extend the scale-dependent bias
formulation to the general situations with primordial anisotropy. We find some
selection rules indicating that some specific parts of a generic anisotropic
bispectrum is picked up by the bias parameter. We argue that the anisotropic
bias is mainly sourced by the angle between the anisotropic direction and the
long wavelength mode in the squeezed limit.


title: Floquet-Bloch theory and topology in periodically driven lattices

abstract:
  We propose a general framework to solve tight binding models in D dimensional
lattices driven by ac electric fields. Our method is valid for arbitrary
driving regimes and allows to obtain effective Hamiltonians for different
external fields configurations. We establish an equivalence with time
independent lattices in D+1 dimensions, and analyze their topological
properties. Further, we demonstrate that non-adiabaticity drives a transition
from topological invariants defined in D+1 to D dimensions. Our approach
provides a theoretical framework to analyze ac driven systems, with potential
applications in topological states of matter, and non-adiabatic topological
quantum computation, predicting novel outcomes for future experiments.


title: Streaming-Codes for Multicast over Burst Erasure Channels

abstract:
  We study the capacity limits of real-time streaming over burst-erasure
channels. A stream of source packets must be sequentially encoded and the
resulting channel packets must be transmitted over a two-receiver burst-erasure
broadcast channel. The source packets must be sequentially reconstructed at
each receiver with a possibly different reconstruction deadline. We study the
associated capacity as a function of burst-lengths and delays at the two
receivers.
  We establish that the operation of the system can be divided into two main
regimes: a low-delay regime and a large-delay regime. We fully characterize the
capacity in the large delay regime. The key to this characterization is an
inherent slackness in the delay of one of the receivers. At every point in this
regime we can reduce the delay of at-least one of the users until a certain
critical value and thus it suffices to obtain code constructions for certain
critical delays. We partially characterize the capacity in the low-delay
regime. Our capacity results involve code constructions and converse techniques
that appear to be novel. We also provide a rigorous information theoretic
converse theorem in the point-to-point setting which was studied by Martinian
in an earlier work.


title: Decomposition rank of UHF-absorbing C*-algebras

abstract:
  Let A be a unital separable simple C*-algebra with a unique tracial state. We
prove that if A is nuclear and quasidiagonal, then A tensored with the
universal UHF-algebra has decomposition rank at most one. Then it is proved
that A is nuclear, quasidiagonal and has strict comparison if and only if A has
finite decomposition rank. For such A, we also give a direct proof that A
tensored with a UHF-algebra has tracial rank zero. Applying this
characterization, we obtain a counter-example to the Powers-Sakai conjecture.


title:
Generalized Sobol sensitivity indices for dependent variables: numerical
  methods

abstract:
  The hierarchically orthogonal functional decomposition of any measurable
function f of a random vector X=(X_1,...,X_p) consists in decomposing f(X) into
a sum of increasing dimension functions depending only on a subvector of X.
Even when X_1,..., X_p are assumed to be dependent, this decomposition is
unique if components are hierarchically orthogonal. That is, two of the
components are orthogonal whenever all the variables involved in one of the
summands are a subset of the variables involved in the other. Setting Y=f(X),
this decomposition leads to the definition of generalized sensitivity indices
able to quantify the uncertainty of Y with respect to the dependent inputs X.
In this paper, a numerical method is developed to identify the component
functions of the decomposition using the hierarchical orthogonality property.
Furthermore, the asymptotic properties of the components estimation is studied,
as well as the numerical estimation of the generalized sensitivity indices of a
toy model. Lastly, the method is applied to a model arising from a real-world
problem.


title: Hausdorff and harmonic measures on non-homogeneous Cantor sets

abstract:
  We consider (not self-similar) Cantor sets defined by a sequence of piecewise
linear functions. We prove that the dimension of the harmonic measure on such a
set is strictly smaller than its Hausdorff dimension. Some Hausdorff measure
estimates for these sets are also provided.


title: The infinite associahedron and R.J. Thompson's group T

abstract:
  In this paper we construct a cellular complex which is an infinite analogue
to Stasheff's associahedra. We prove that it is contractible and state that its
(combinatorial) automorphism group is isomorphic to a semi-direct product of
R.J. Thompson's group $T$ with $\mathbb{Z}/2\mathbb{Z}$.


title:
On the Computing of the Minimum Distance of Linear Block Codes by
  Heuristic Methods

abstract:
  The evaluation of the minimum distance of linear block codes remains an open
problem in coding theory, and it is not easy to determine its true value by
classical methods, for this reason the problem has been solved in the
literature with heuristic techniques such as genetic algorithms and local
search algorithms. In this paper we propose two approaches to attack the
hardness of this problem. The first approach is based on genetic algorithms and
it yield to good results comparing to another work based also on genetic
algorithms. The second approach is based on a new randomized algorithm which we
call Multiple Impulse Method MIM, where the principle is to search codewords
locally around the all-zero codeword perturbed by a minimum level of noise,
anticipating that the resultant nearest nonzero codewords will most likely
contain the minimum Hamming-weight codeword whose Hamming weight is equal to
the minimum distance of the linear code.


title: 2-stack pushall sortable permutations

abstract:
  In the 60's, Knuth introduced stack-sorting and serial compositions of
stacks. In particular, one significant question arise out of the work of Knuth:
how to decide efficiently if a given permutation is sortable with 2 stacks in
series? Whether this problem is polynomial or NP-complete is still unanswered
yet. In this article we introduce 2-stack pushall permutations which form a
subclass of 2-stack sortable permutations and show that these two classes are
closely related. Moreover, we give an optimal O(n^2) algorithm to decide if a
given permutation of size n is 2-stack pushall sortable and describe all its
sortings. This result is a step to the solve the general 2-stack sorting
problem in polynomial time.


title: Hertz potentials and asymptotic properties of massless fields

abstract:
  In this paper we analyze Hertz potentials for free massless spin-s fields on
the Minkowski spacetime, with data in weighted Sobolev spaces. We prove
existence and pointwise estimates for the Hertz potentials using a weighted
estimate for the wave equation. This is then applied to give weighted estimates
for the solutions of the spin-s field equations, for arbitrary half-integer s.
In particular, the peeling properties of the free massless spin-s fields are
analyzed for initial data in weighted Sobolev spaces with arbitrary,
non-integer weights.


title:
Study of a fully implicit scheme for the drift-diffusion system.
  Asymptotic behavior in the quasi-neutral limit

abstract:
  In this paper, we are interested in the numerical approximation of the
classical time-dependent drift-diffusion system near quasi-neutrality. We
consider a fully implicit in time and finite volume in space scheme, where the
convection-diffusion fluxes are approximated by Scharfetter-Gummel fluxes. We
establish that all the a priori estimates needed to prove the convergence of
the scheme does not depend on the Debye length $\lambda$. This proves that the
scheme is asymptotic preserving in the quasi-neutral limit $\lambda \to 0$.


title: Flux-controlled quantum computation with Majorana fermions

abstract:
  Majorana fermions hold promise for quantum computation, because their
non-Abelian braiding statistics allows for topologically protected operations
on quantum information. Topological qubits can be constructed from pairs of
well-separated Majoranas in networks of nanowires. The coupling to a
superconducting charge qubit in a transmission line resonator (transmon)
permits braiding of Majoranas by external variation of magnetic fluxes. We show
that readout operations can also be fully flux-controlled, without requiring
microscopic control over tunnel couplings. We identify the minimal circuit that
can perform the initialization--braiding--measurement steps required to
demonstrate non-Abelian statistics. We introduce the Random Access Majorana
Memory, a scalable circuit that can perform a joint parity measurement on
Majoranas belonging to a selection of topological qubits. Such multi-qubit
measurements allow for the efficient creation of highly entangled states and
simplify quantum error correction protocols by avoiding the need for ancilla
qubits.


title:
Determination of the magnetization profile of Co/Mg periodic multilayers
  by magneto-optic Kerr effect and X-ray magnetic resonant reflectivity

abstract:
  The resonant magnetic reflectivity of Co/Mg multilayers around the Co L2,3
absorption edge is simulated then measured on a specifically designed sample.
The dichroic signal is obtained when making the difference between the two
reflectivities measured with the magnetic field applied in two opposite
directions parallel to the sample surface. The simulations show that the
existence of magnetic dead layers at the interfaces between the Co and Mg
layers leads to an important increase of the dichroic signal measured in the
vicinity of the third Bragg peak that otherwise should be negligible. The
measurements are in agreement with the model introducing 0.25 nm thick dead
layers. This is attributed to the Co atoms in contact with the Mg layers and
thus we conclude that the Co-Mg interfaces are abrupt from the magnetic point
of view.


title:
Joint Minkowski Functionals and Bispectrum Constraints on
  Non-Gaussianity in the CMB

abstract:
  Two of the most commonly used tools to constrain the primordial
non-Gaussianity are the bispectrum and the Minkowski functionals of CMB
temperature anisotropies. These two measures of non-Gaussianity in principle
provide distinct (though correlated) information, but in the past constraints
from them have only been loosely compared, and not statistically combined. In
this work we evaluate, for the first time, the covariance matrix between the
local non-Gaussianity coefficient fnl estimated through the bispectrum and
Minkowski functionals. We find that the estimators are positively correlated,
with corerlation coefficient r ~ 0.3. Using the WMAP7 data to combine the two
measures and accounting for the point-source systematics, we find the combined
constraint fnl=37+/-28, which has a ~20% smaller error than either of the
individual constraints.


title:
On the Equivalence of the Entropic Curvature-Dimension Condition and
  Bochner's Inequality on Metric Measure Spaces

abstract:
  We prove the equivalence of the curvature-dimension bounds of
Lott-Sturm-Villani (via entropy and optimal transport) and of Bakry--\'Emery
(via energy and \Gamma_2$-calculus) in complete generality for infinitesimally
Hilbertian metric measure spaces. In particular, we establish the full Bochner
inequality on such metric measure spaces. Moreover, we deduce new contraction
bounds for the heat flow on Riemannian manifolds and on mms in terms of the
$L^2$-Wasserstein distance.


title:
Hierarchical hydropathic evolution of influenza glycoproteins (N2, H3,
  A/H3N2) under relentless vaccination pressure

abstract:
  Hemagglutinin (HA) and neuraminidase (NA) are highly variable envelope
glycoproteins. Here hydropathic analysis, previously applied to quantify common
flu (H1N1) evolution (1934-), is applied to the evolution of less common but
more virulent (avian derived) H3N2 (1968-), beginning with N2. Whereas N1
exhibited opposing migration and vaccination pressures, the dominant N2 trend
is due to vaccination, with only secondary migration interactions. Separation
and evaluation of these effects is made possible by the use of two distinct
hydropathic scales representing first-order and second-order thermodynamic
interactions. The evolutions of H1 and H3 are more complex, with larger
competing migration and vaccination effects. The linkages of H3 and N2
evolutionary trends are examined on two modular length scales, medium
(glycosidic) and large (corresponding to sialic acid interactions). The
hierarchical hydropathic results complement and greatly extend advanced
phylogenetic results obtained from similarity studies. They exhibit simple
quantitative trends that can be transferred to engineer oncolytic properties of
other viral proteins to treat recalcitrant cancers.


title:
Adaptive Distributed Space-Time Coding in Cooperative MIMO Relaying
  Systems using Limited Feedback

abstract:
  An adaptive randomized distributed space-time coding (DSTC) scheme is
proposed for two-hop cooperative MIMO networks. Linear minimum mean square
error (MMSE) receiver filters and randomized matrices subject to a power
constraint are considered with an amplify-and-forward (AF) cooperation
strategy. In the proposed DSTC scheme, a randomized matrix obtained by a
feedback channel is employed to transform the space-time coded matrix at the
relay node. The effect of the limited feedback and feedback errors are
considered. Linear MMSE expressions are devised to compute the parameters of
the adaptive randomized matrix and the linear receive filters. A stochastic
gradient algorithm is also developed with reduced computational complexity. The
simulation results show that the proposed algorithms obtain significant
performance gains as compared to existing DSTC schemes.


title: Modeling a Sensor to Improve its Efficacy

abstract:
  Robots rely on sensors to provide them with information about their
surroundings. However, high-quality sensors can be extremely expensive and
cost-prohibitive. Thus many robotic systems must make due with lower-quality
sensors. Here we demonstrate via a case study how modeling a sensor can improve
its efficacy when employed within a Bayesian inferential framework. As a test
bed we employ a robotic arm that is designed to autonomously take its own
measurements using an inexpensive LEGO light sensor to estimate the position
and radius of a white circle on a black field. The light sensor integrates the
light arriving from a spatially distributed region within its field of view
weighted by its Spatial Sensitivity Function (SSF). We demonstrate that by
incorporating an accurate model of the light sensor SSF into the likelihood
function of a Bayesian inference engine, an autonomous system can make improved
inferences about its surroundings. The method presented here is data-based,
fairly general, and made with plug-and play in mind so that it could be
implemented in similar problems.


title: Breakdown of self-averaging in the Bose glass

abstract:
  We study the square-lattice Bose-Hubbard model with bounded random on-site
energies at zero temperature. Starting from a dual representation obtained from
a strong-coupling expansion around the atomic limit, we employ a real-space
block decimation scheme. This approach is non-perturbative in the disorder and
enables us to study the renormalization-group flow of the induced random-mass
distribution. In both insulating phases, the Mott insulator and the Bose glass,
the average mass diverges, signaling short range superfluid correlations. The
relative variance of the mass distribution distinguishes the two phases,
renormalizing to zero in the Mott insulator and diverging in the Bose glass.
Negative mass values in the tail of the distribution indicate the presence of
rare superfluid regions in the Bose glass. The breakdown of self-averaging is
evidenced by the divergent relative variance and increasingly non-Gaussian
distributions. We determine an explicit phase boundary between the Mott
insulator and Bose glass.


title: The 21cm Power Spectrum and the Shapes of Non-Gaussianity

abstract:
  We consider how measurements of the 21cm radiation from the epoch of
reionization (z=8-12) can constrain the amplitudes of various `shapes' of
primordial non-Gaussianity. The limits on these shapes, each parametrized by
the non-linear parameter, f_NL, can reveal whether the physics of inflation is
more complex than the standard single-field, slow-roll scenario. In this work,
we quantify the effects of the well-known local, equilateral, orthogonal and
folded types of non-Gaussianities on the 21cm power spectrum, which is expected
to be measured by upcoming radio arrays such as the Square-Kilometre Array
(SKA). We also assess the prospects of the SKA in constraining these
non-Gaussianities, and found constraints that are comparable with those
expected from cosmic-microwave-background experiments such as Planck. We show
that the limits on various f_NL can be tightened to O(1) using a radio array
with a futuristic but realistic set of specifications.


title:
A Possible Formation Scenario for Dwarf Spheroidal Galaxies I: Fiducial
  Model

abstract:
  We use numerical simulations to study a formation scenario for dwarf
spheroidal galaxies in which their stellar populations are the products of the
dissolution of open star clusters and stellar associations within cosmological
dark matter haloes. This paper shows that this process gives rise to objects
which resemble the observed dwarf spheroidal satellites of the Milky Way
without invoking external influences. The presence of long-lived kinematic
substructures within the stellar components of these objects affects their
projected velocity dispersions. We find that this in turn affects mass
estimates based on the projected velocity dispersion profiles which may
over-estimate the actual dark matter halo mass depending on the amount of
substructure which is present. Our models make predictions about the detailed
kinematic and photometric properties of the dSphs which can be tested using
future observations.


title:
The bulge-halo conspiracy in massive elliptical galaxies: implications
  for the stellar initial mass function and halo response to baryonic processes

abstract:
  Recent studies have shown that massive elliptical galaxies have total mass
density profiles within an effective radius that can be approximated as
\rho_{tot}\propto r^{-\gamma'}, with mean slope <\gamma'>=2.08 \pm 0.03 and
scatter \sigma_\gamma'=0.16 \pm 0.02. The small scatter of the slope (known as
the bulge-halo conspiracy) is not generic in LCDM based models and therefore
contains information about the galaxy formation process. We compute the
distribution of \gamma' for LCDM-based models that reproduce the observed
correlations between stellar mass, velocity dispersion, and effective radius of
early-type galaxies in the SDSS. The models have a range of stellar initial
mass functions (IMFs) and dark halo responses to galaxy formation. The observed
distribution of \gamma' is well reproduced by a model with cosmologically
motivated but uncontracted dark matter haloes, and a Salpeter-type IMF. Other
models are on average ruled out by the data, even though they may happen in
individual cases. Models with adiabatic halo contraction (and lighter IMFs)
predict too small values of \gamma'. Models with halo expansion, or
mass-follows-light predict too high values of \gamma'. Our study shows that the
non-homologous structure of massive early-type galaxies can be precisely
reproduced by LCDM models if the IMF is not universal and if mechanisms such as
feedback from active galactic nuclei, or dynamical friction, effectively on
average counterbalance the contraction of the halo expected as a result of
baryonic cooling.


title: Vortex Lattices and Crystalline Geometries

abstract:
  We consider $AdS_2 \times R^2$ solutions supported by a magnetic field, such
as those which arise in the near-horizon limit of magnetically charged $AdS_4$
Reissner-Nordstrom black branes. In the presence of an electrically charged
scalar field, such magnetic solutions can be unstable to spontaneous formation
of a vortex lattice. We solve the coupled partial differential equations which
govern the charged scalar, gauge field, and metric degrees of freedom to lowest
non-trivial order in an expansion around the critical point, and discuss the
corrections to the free energy and thermodynamic functions arising from the
formation of the lattice. We describe how such solutions can also be
interpreted, via S-duality, as characterizing infrared crystalline phases of
conformal field theories doped by a chemical potential, but in zero magnetic
field; the doped conformal field theories are dual to geometries that exhibit
dynamical scaling and hyperscaling violation.


title:
The Clustering of Galaxies in the SDSS-III Baryon Oscillation
  Spectroscopic Survey: Measuring H(z) and D_A(z) at z = 0.57 with Clustering
  Wedges

abstract:
  We analyze the 2D correlation function of the SDSS-III Baryon Oscillation
Spectroscopic Survey (BOSS) CMASS sample of massive galaxies of the ninth data
release to measure cosmic expansion H and the angular diameter distance D_A at
a mean redshift of <z> = 0.57. We apply, for the first time, a new correlation
function technique called clustering wedges. Using a physically motivated
model, the anisotropic baryonic acoustic feature in the galaxy sample is
detected at a significance level of 4.7 sigma compared to a featureless model.
The baryonic acoustic feature is used to obtain model independent constraints
cz/H/r_s = 12.28 +- 0.82 (6.7 per-cent accuracy) and D_A/r_s = 9.05 +- 0.27
(3.0 per-cent) with a correlation coefficient of -0.5, where r_s is the sound
horizon scale at the end of the baryonic drag era. We conduct thorough tests on
the data and 600 simulated realizations, finding robustness of the results
regardless of the details of the analysis method. Combining with r_s
constraints from the Cosmic Microwave Background we obtain H(0.57) = 90.8 +-
6.2 kms-1Mpc-1 and D_A(0.57) = 1386 +- 45 Mpc. We use simulations to forecast
results of the final BOSS CMASS data set. We apply the reconstruction technique
on the simulations demonstrating that the sharpening of the anisotropic
baryonic acoustic feature should improve the detection as well as tighten
constraints of H and D_A by 30 per-cent on average.


title:
Regularity underlying complexity: a redshift-independent description of
  the continuous variation of galaxy-scale molecular gas properties in the
  mass-star formation rate plane

abstract:
  Star-forming galaxies (SFGs) display a continuous distribution of specific
star formation rates (sSFR) which can be approximated by the superposition of
two log-normal distributions. The 1st of these encompasses the main sequence
(MS) of SFGs, the 2nd one a rarer population of starbursts (SB). We show that
the sSFR-distribution of SBs can be regarded as the result of a physical
process (plausibly merging) taking the mathematical form of a log-normal
boosting kernel and enhancing star formation activity. We explore the utility
of splitting the star-forming population into MS and SB galaxies - an approach
we term "2-Star Formation Mode" (2-SFM) framework - for understanding their
molecular gas properties. Variations of star formation efficiency (SFE) and gas
fractions among SFGs take a simple, redshift-independent form, once these
quantities are normalized to the value of an average MS galaxy. The change in
SFE for galaxies undergoing a starburst event scales supra-linearly with the
SFR-increase, as expected for mergers. This implies a continuous distribution
of galaxies in the Schmidt-Kennicutt plane that separates more clearly into
loci for SBs and normal galaxies than observed in SFR vs. M* space. SBs with
the largest deviations (>10-fold) from the MS, like many local ULIRGs, are not
average SBs, but even rarer events with progenitors having larger gas fractions
than typical MS galaxies. We statistically infer that the gas fractions of
typical SBs decrease by a factor of 2 to 3 with respect to their direct MS
progenitors, as expected to occur in short-term SFR-boosts during which
internal gas reservoirs are drained more quickly than gas is accreted from the
cosmic web. We predict variations of the CO-to-H2 conversion factor in the
SFR-M* plane and provide evidence that the higher sSFR of distant galaxies is a
direct consequence of larger gas fraction in these systems.


title:
The Effect of Spatial Gradients in Stellar Mass-to-Light Ratio on Black
  Hole Mass Measurements

abstract:
  We have tested the effect of spatial gradients in stellar mass-to-light ratio
(Y) on measurements of black hole masses (MBH) derived from stellar orbit
superposition models. Such models construct a static gravitational potential
for a galaxy and its central black hole, but typically assume spatially uniform
Y. We have modeled three giant elliptical galaxies with gradients alpha = d(log
Y)/d(log r) from -0.2 to +0.1. Color and line strength gradients suggest mildly
negative alpha in these galaxies. Introducing a negative (positive) gradient in
Y increases (decreases) the enclosed stellar mass near the center of the galaxy
and leads to systematically smaller (larger) MBH measurements. For models with
alpha = -0.2, the best-fit values of MBH are 28%, 27%, and 17% lower than the
constant-Y case, in NGC 3842, NGC 6086, and NGC 7768, respectively. For alpha =
+0.1, MBH are 14%, 22%, and 17% higher than the constant-Y case for the three
respective galaxies. For NGC 3842 and NGC 6086, this bias is comparable to the
statistical errors from individual modeling trials. At larger radii, negative
(positive) gradients in Y cause the total stellar mass to decrease (increase)
and the dark matter fraction within one effective radius to increase
(decrease).


title:
Quark-Lepton Mass Relation and CKM mixing in an A4 Extension of the
  Minimal Supersymmetric Standard Model

abstract:
  An interesting mass relation between down type quarks and charged leptons has
been recently predicted within a supersymmetric SU(3)_c \times SU(2)_L \times
U(1)_Y model based on the A4 flavor symmetry. Here we propose a simple
extension which provides an adequate full description of the quark sector. By
adding a pair of vector-like up-quarks we show how the CKM entries Vub, Vcb,
Vtd and Vts arise from deviations of the unitarity. We perform an analysis
including the most relevant observables in the quark sector, such as
oscillations and rare decays of Kaons, Bd and Bs mesons. In the lepton sector,
model predicts an inverted hierarchy for the neutrino masses leading to a
potentially observable rate of neutrinoless double beta decay.


title: Light inflaton after LHC8 and WMAP9 results

abstract:
  We update the allowed parameter space of the simple chaotic inflationary
model with quartic potential and light inflaton [Bezrukov,Gorbunov'2009] taking
into account recent results from cosmology (CMB observations from SPT, ACT and
WMAP) and from particle physics (LHC hints of the SM Higgs boson). The
non-minimal (yet small) coupling to gravity of the inflaton becomes essential
to fit the observational data. The inflaton has mass above 300 MeV and can be
searched for at B-factories in B-meson two-body decays to kaon and inflaton.
The inflaton lifetime depends on the model parameters, resulting in various
inflaton signatures: either a missing energy, or a displaced vertex from the
B-meson decay position, or a resonance in the Dalitz plot of a three particle
decay. We also discuss the implementation of the inflaton model to the nuMSM,
where the inflaton can be responsible for production of the dark matter sterile
neutrino in the early Universe.


title:
The clustering of galaxies in the SDSS-III Baryon Oscillation
  Spectroscopic Survey: cosmological constraints from the full shape of the
  clustering wedges

abstract:
  We explore the cosmological implications of the clustering wedges, xi_perp(s)
and xi_para(s), of the CMASS Data Release 9 (DR9) sample of the Baryon
Oscillation Spectroscopic Survey (BOSS). These clustering wedges are defined by
averaging the full two-dimensional correlation function, xi(mu,s), over the
ranges 0<mu<0.5 and 0.5<mu<1, respectively. These measurements allow us to
constrain the parameter combinations D_A(z)/r_s(z_d)=9.03 +- 0.21 and
cz/(r_s(z_d)H(z)) = 12.14 +- 0.43 at the mean redsfhit of the sample, z=0.57.
We combine the information from the clustering wedges with recent measurements
of CMB, BAO and type Ia supernovae to obtain constraints on the cosmological
parameters of the standard LCDM model and a number of potential extensions. The
information encoded in the clustering wedges is most useful when the dark
energy equation of state is allowed to deviate from its standard LCDM value.
The combination of all datasets shows no evidence of a deviation from a
constant dark energy equation of state, in which case we find w_DE = -1.013 +-
0.064, in complete agreement with a cosmological constant. We explore potential
deviations from general relativity by constraining the growth rate f(z)=d ln
D(a)/ d ln a, in which case the combination of the CMASS clustering wedges with
CMB data implies f(z=0.57)=0.719 +- 0.094, in accordance with the predictions
of GR. Our results clearly illustrate the additional constraining power of
anisotropic clustering measurements with respect to that of angle-averaged
quantities.


title: The Digital Motion Control System for the Submillimeter Array Antennas

abstract:
  We describe the design and performance of the digital servo and motion
control system for the 6-meter diameter parabolic antennas of the Submillimeter
Array (SMA) on Mauna Kea, Hawaii. The system is divided into three nested
layers operating at a different, appropriate bandwidth. (1) A rack-mounted,
real-time Unix system runs the position loop which reads the high resolution
azimuth and elevation encoders and sends velocity and acceleration commands at
100 Hz to a custom-designed servo control board (SCB). (2) The
microcontroller-based SCB reads the motor axis tachometers and implements the
velocity loop by sending torque commands to the motor amplifiers at 558 Hz. (3)
The motor amplifiers implement the torque loop by monitoring and sending
current to the three-phase brushless drive motors at 20 kHz. The velocity loop
uses a traditional proportional-integral-derivative (PID) control algorithm,
while the position loop uses only a proportional term and implements a command
shaper based on the Gauss error function. Calibration factors and software
filters are applied to the tachometer feedback prior to the application of the
servo gains in the torque computations. All of these parameters are remotely
adjustable in software. The three layers of the control system monitor each
other and are capable of shutting down the system safely if a failure or
anomaly occurs. The Unix system continuously relays antenna status to the
central observatory computer via reflective memory. In each antenna, a Palm Vx
hand controller displays system status and allows full local control of the
drives in an intuitive touchscreen user interface. It can also be connected
outside the cabin for convenience during antenna reconfigurations. Excellent
tracking performance (0.3 arcsec rms) is achieved with this system. It has been
in reliable operation on 8 antennas for over 10 years and has required minimal
maintenance.


title: Holographic charge density waves

abstract:
  We show that strongly coupled holographic matter at finite charge density can
exhibit charge density wave phases which spontaneously break translation
invariance while preserving time-reversal and parity invariance. We show that
such phases are possible within Einstein-Maxwell-dilaton theory in general
spacetime dimensions. We also discuss related spatially modulated phases when
there is an additional coupling to a second vector field, possibly with
non-zero mass. We discuss how these constructions, and others, should be
associated with novel spatially modulated ground states.


title:
Fueling AGN-I: How the Global Characteristics of the Central Kiloparsec
  of Seyferts differ from Quiescent Galaxies

abstract:
  In a matched sample of Seyfert and quiescent galaxies we simultaneously probe
the stellar and molecular gas kinematics from 1 kpc down to 50 pc with the aim
of identifying the dynamical processes dictating black hole accretion rates.
This first paper compares the global characteristics of a sample of ten
galaxies. We find several differences within a radius of 500 pc that are
correlated with Active Galactic Nucleus (AGN) activity. The Seyferts have: (1)
a more centrally concentrated nuclear stellar surface brightness with lower
stellar luminosities beyond a radius of 100 pc, (2) a lower stellar velocity
dispersion within a radius of 200 pc, (3) elevated H2 luminosity out to a
radius of at least 250 pc, and (4) more centrally concentrated H2 surface
brightness profiles. These observed differences can be interpreted as evidence
for Seyfert galaxies having a dynamically cold (in comparison to the bulge)
nuclear structure composed of a significant gas reservoir and a relatively
young stellar population. This structure is undetected (and possibly does not
exist) in quiescent galaxies. The presence of such a nuclear structure in
Seyfert galaxies provides evidence for inflow of the surrounding interstellar
medium since the nuclear stellar population requires a supply of gas from which
to form. The fueling of a Seyfert AGN is thus associated with the formation of
a dynamically cold component of gas and stars on scales of hundreds of parsecs.


title:
The role of major mergers in shaping galaxies at 2<z<4 in the VUDS and
  VVDS surveys

abstract:
  The mass assembly of galaxies can proceed through different physical
processes. Here we report on the spectroscopic identification of close physical
pairs of galaxies at redshifts 2 <z < 4 and discuss the impact of major mergers
in shaping galaxies at these early cosmological times. We aim to identify and
characterize close physical pairs of galaxies destined to merge and use their
properties to infer the contribution of merging processes to the early mass
assembly of galaxies. We search for galaxy pairs with a transverse separation
r_p < 25 h^{-1} kpc and a velocity difference Delta v < 500 km s^{-1} using the
VIMOS VLT Deep Survey (VVDS) and early data from the VIMOS Ultra Deep Survey
(VUDS) that comprise a sample of 1111 galaxies with spectroscopic redshifts
measurements at redshifts 1.8 < z < 4 in the COSMOS, ECDFS, and VVDS-02h
fields. We analyse their spectra and associated visible and near-infrared
photometry to assess the main properties of merging galaxies that have an
average stellar mass M_{star}=2.3 x 10^{10} M_{sun} at these redshifts. Using
the 12 physical pairs found in our sample we obtain a first estimate of the
merger fraction at these rdshifts, fmerg ~(15-20)%. The pair separations
indicate that these pairs will merge within 1 Gyr, on average, with each
producing a more massive galaxy by the time the cosmic star formation peaks at
z~1-2. From the average mass ratio between galaxies in the pairs, the stellar
mass of the resulting galaxy after merging will be ~60% larger than the most
massive galaxy in the pair before merging. We conclude that major merging of
galaxy pairs is on-going at 2<z<4 and significantly contributing to the major
assembly phase of galaxies at this early epoch.


title:
The strength of genetic interactions scales weakly with the mutational
  effects

abstract:
  Genetic interactions pervade every aspect of biology, from evolutionary
theory where they determine the accessibility of evolutionary paths, to
medicine where they contribute to complex genetic diseases. Until very
recently, studies on epistatic interactions have been based on a handful of
mutations, providing at best anecdotal evidence about the frequency and the
typical strength of genetic interactions. In this study we analyze the publicly
available Data Repository of Yeast Genetic INteractions (DRYGIN), which
contains the growth rates of over five million double gene knockout mutants. We
discuss a geometric definition of epistasis which reveals a simple and
surprisingly weak scaling law for the characteristic strength of genetic
interactions as a function of the effects of the mutations being combined. We
then utilize this scaling to quantify the roughness of naturally occurring
fitness landscapes. Finally, we show how the observed roughness differs from
what is predicted by Fisher's geometric model of epistasis and discuss its
consequences on the evolutionary dynamics. Although epistatic interactions
between specific genes remain largely unpredictable, the statistical properties
of an ensemble of interactions can display conspicuous regularities and be
described by simple mathematical laws. By exploiting the amount of data
produced by modern high-throughput techniques it is now possible to thoroughly
test the predictions of theoretical models of genetic interactions and to build
informed computational models of evolution on realistic fitness landscapes.


title:
From Amateurs to Connoisseurs: Modeling the Evolution of User Expertise
  through Online Reviews

abstract:
  Recommending products to consumers means not only understanding their tastes,
but also understanding their level of experience. For example, it would be a
mistake to recommend the iconic film Seven Samurai simply because a user enjoys
other action movies; rather, we might conclude that they will eventually enjoy
it -- once they are ready. The same is true for beers, wines, gourmet foods --
or any products where users have acquired tastes: the `best' products may not
be the most `accessible'. Thus our goal in this paper is to recommend products
that a user will enjoy now, while acknowledging that their tastes may have
changed over time, and may change again in the future. We model how tastes
change due to the very act of consuming more products -- in other words, as
users become more experienced. We develop a latent factor recommendation system
that explicitly accounts for each user's level of experience. We find that such
a model not only leads to better recommendations, but also allows us to study
the role of user experience and expertise on a novel dataset of fifteen million
beer, wine, food, and movie reviews.


title: Revisiting charmless hadronic B decays to scalar mesons

abstract:
  Hadronic charmless B decays to scalar mesons are studied within the framework
of QCD factorization (QCDF). Considering two different scenarios for scalar
mesons above 1 GeV, we find that the data favor the scenario in which the
scalars $a_0(1450)$ and $K_0^*(1430)$ are the lowest lying $q\bar q$ bound
states. This in turn implies a preferred four-quark nature for light scalars
below 1 GeV. Assuming $K_0^*(1430)$ being a lowest lying $q\bar s$ state, we
show that the data of $B\to K_0^*(1430)\eta^{(')}$ and $B\to
K_0^*(1430)(\rho,\omega,\phi)$ can be accommodated in QCDF without introducing
power corrections induced from penguin annihilation, while the predicted
$B^-\to \ov K_0^{*0}(1430)\pi^-$ and $\ov B^0\to K_0^{*-}(1430)\pi^+$ are too
small compared to experiment. In principle, the data of $K_0^*(1430)\pi$ modes
can be explained if penguin-annihilation induced power corrections are taken
into account. However, this will destroy the agreement between theory and
experiment for $B\to K_0^*(1430)(\eta^{(')},\rho,\omega,\phi)$. Contrary to the
pseudoscalar meson sector where $B\to K\eta'$ has the largest rate in 2-body
decays of the $B$ meson, we show that $Br(B\to K_0^*\eta')<\B(B\to K_0^*\eta)$.
The decay $\ov B^0\to a_0(980)^+K^-$ is found to have a rate much smaller than
that of $\ov B^0\to a_0(980)^+\pi^-$ in QCDF, while it is the other way around
in pQCD. Experimental measurements of these two modes will help discriminate
between these two different approaches. Assuming 2-quark bound states for
$f_0(980)$ and $f_0(500)$, the observed large rates of $f_0(980)K$ and
$f_0(980)K^*$ modes can be explained in QCDF with the $f_0(980)\!-\!f_0(500)$
mixing angle $\theta$ in the vicinity of $20^\circ$.


title:
Looking for new charged states at the LHC: Signatures of Magnetic and
  Rayleigh Dark Matter

abstract:
  Magnetic and Rayleigh dark matter are models describing weak interactions of
dark matter with electromagnetism through non-renormalizable operators of
dimensions 5 and 7, respectively. Such operators motivate the existence of
heavier states that couple to dark matter and are also charged under the
electroweak interactions. The recent hints of a gamma-ray line in the Fermi
data suggest that these states may be light enough to be produced at the LHC.
We categorize such states according to their charges and decay modes, and we
examine the corresponding LHC phenomenology. We emphasize unconstrained models
that can be discovered in targeted searches at the upgraded LHC run, while also
enumerating models excluded by current data. Generally, models with
SU(2)-singlet states or models where the charged states decay predominantly to
tau leptons and/or gauge bosons are still viable. We propose searches to
constrain such models and, in particular, find superior performance over
existing proposals for multi-tau analyses. Finally, we note several scenarios,
especially those dominated by tau final states, that cannot be probed even with
300/fb at LHC14, motivating the further refinement of tau lepton searches to
improve sensitivity to such final states.


title:
Reducing theoretical uncertainties for exclusive Higgs plus one-jet
  production at the LHC

abstract:
  We resum a class of large Sudakov logarithms affecting Higgs boson production
in the exclusive one-jet bin at the LHC. We extend previous results by
calculating the full one-loop soft function for this process, which extends the
accuracy of the resummation to include the leading three logarithmic
corrections at each order in the QCD coupling constant. We match this result to
the next-to-leading order cross section and present a detailed numerical study
assuming realistic LHC cuts. Careful attention is paid to the matching
procedure, and to the theoretical uncertainties induced by residual scale
variation. We find that the matched NLL'+ NLO cross section has significantly
smaller uncertainties than the fixed-order result, and can be used to alleviate
the theoretical errors hindering current Higgs analyses at the LHC.


title: Extensions of translation invariant valuations on polytopes

abstract:
  We study translation invariant, real-valued valuations on the class of convex
polytopes in Euclidean space and discuss which continuity properties are
sufficient for an extension of such valuations to all convex bodies. For this
purpose, we introduce flag support measures of convex bodies via a local
Steiner formula and derive some of the properties of these measures.


title:
Two remarks on polynomially bounded reducts of the restricted analytic
  field with exponentiation

abstract:
  This article presents two constructions motivated by a conjecture of L. van
den Dries and C. Miller concerning the restricted analytic field with
exponentiation. The first construction provides an example of two o-minimal
expansions of a real closed field that possess the same field of germs at
infinity of one-variable functions and yet define different global one-variable
functions. The second construction gives an example of a family of infinitely
many distinct polynomially bounded reducts (all this in the sense of
definability) of the restricted analytic field with exponentiation.