title: Stability of strongly Gorenstein flat modules

abstract:
  A left $R$-module $M$ is called two-degree Ding projective if there exists an
exact sequence $...\longrightarrow D_{1}\longrightarrow D_{0}\longrightarrow
D_{-1}\longrightarrow D_{-2}\longrightarrow...$ of Ding projective left
$R$-modules such that $M\cong\ker (D_{0}\longrightarrow D_{-1})$ and $\Hom_{R}
(-, F)$ leaves the sequence exact for any flat (or Gorenstein flat) left
$R$-module $F$. In this paper, we show that the two-degree Ding projective
modules are nothing more than the Ding projective modules.


title: From the Micro-scale to Collective Crowd Dynamics

abstract:
  This paper deals with the kinetic theory modeling of crowd dynamics with the
aim of showing how the dynamics at the micro-scale is transferred to the
dynamics of collective behaviors. The derivation of a new model is followed by
a qualitative analysis of the initial value problem. Existence of solutions is
proved for arbitrary large times, while simulations are developed by
computational schemes based on splitting methods, where the transport equations
treated by finite difference methods for hyperbolic equations. Some preliminary
reasonings toward the modeling of panic conditions are proposed.


title: Constraints on the Synchrotron Emission Mechanism in GRBs

abstract:
  We reexamine the general synchrotron model for GRBs' prompt emission and
determine the regime in the parameter phase space in which it is viable. We
characterize a typical GRB pulse in terms of its peak energy, peak flux and
duration and use the latest Fermi observations to constrain the high energy
part of the spectrum. We solve for the intrinsic parameters at the emission
region and find the possible parameter phase space for synchrotron emission.
Our approach is general and it does not depend on a specific energy dissipation
mechanism. Reasonable synchrotron solutions are found with energy ratios of
$10^{-4}<\epsilon_B/\epsilon_e<10$, bulk Lorentz factor values of
$300<\Gamma<3000$, typical electrons' Lorentz factor values of $3\times
10^3<\gamma_e<10^5$ and emission radii of the order $10^{15}cm<R<10^{17}$cm.
Most remarkable among those are the rather large values of the emission radius
and the electron's Lorentz factor. We find that soft (with peak energy less
than 100KeV) but luminous (isotropic luminosity of $~1.5 \times 10^{53}$)
pulses are inefficient. This may explain the lack of strong soft bursts. In
cases when most of the energy is carried out by the kinetic energy of the flow,
such as in the internal shocks, the synchrotron solution requires that only a
small fraction of the electrons are accelerated to relativistic velocities by
the shocks. We show that future observations of very high energy photons from
GRBs by CTA, could possibly determine all parameters of the synchrotron model
or rule it out altogether.


title:
Threshold $\pi^0$ photoproduction in relativistic chiral perturbation
  theory

abstract:
  We present a calculation of $\pi^0$ photoproduction on the proton in
manifestly Lorentz-invariant baryon chiral perturbation theory up to and
including chiral order $q^4$. With the results we analyze the latest $\pi^0$
photoproduction data in the threshold region obtained at the Mainz Microtron.
In the calculation of observables and the fit of the low-energy constants, we
take $S$, $P$, and $D$ waves into account. We compare the results for the
multipoles with the corresponding single-energy analysis. Furthermore, we also
fit the $O(q^4)$ heavy-baryon chiral perturbation theory calculation and
compare both results. We provide predictions for several polarization
observables for future experiments. Finally, we discuss the $\beta$ parameter
of the unitarity cusp which is related to the breaking of isospin symmetry.


title: Slim unicorns and uniform hyperbolicity for arc graphs and curve graphs

abstract:
  We describe unicorn paths in the arc graph and show that they form 1-slim
triangles and are invariant under taking subpaths. We deduce that all arc
graphs are 7-hyperbolic. Considering the same paths in the arc and curve graph,
this also shows that all curve graphs are 17-hyperbolic, including closed
surfaces.


title:
Improving the Fermilab Booster Notching Efficiency, Beam Losses and
  Radiation Levels

abstract:
  Currently a fast vertical 1.08-m long kicker (notcher) located in the
Fermilab Booster Long-5 straight section is used to remove 3 out of 84
circulating bunches after injection to generate an abort gap. With magnetic
field of 72.5 Gauss it removes only 87% of the 3-bunch intensity at 400 MeV,
with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-6
collimators, and 1% in the rest of the ring. We propose to improve the notching
efficiency and reduce beam loss in the Booster by using two horizontal kickers
in the Long-12 section. The STRUCT calculations show that using such horizontal
notchers, one can remove up to 99% of the 3-bunch intensity at 400-700 MeV,
directing 96% of it to a new beam dump at the Long-13 section. This fully
decouples notching and collimation. The beam dump absorbs most of the impinging
proton energy in its jaws. The latter are encapsulated into an appropriate
radiation shielding that reduces impact on the machine components, personnel
and environment to the tolerable levels. The MARS simulations show that
corresponding prompt and residual radiation levels can be reduced ten times
compared to the current ones.


title: Random intersection graph process

abstract:
  We introduce a random intersection graph process aimed at modeling sparse
evolving affiliation networks that admit tunable (power law) degree
distribution and assortativity and clustering coefficients. We show the
asymptotic degree distribution and provide explicit asymptotic formulas for
assortativity and clustering coefficients.


title:
The spectral curve and the Schroedinger equation of double Hurwitz
  numbers and higher spin structures

abstract:
  We derive the spectral curves for $q$-part double Hurwitz numbers, $r$-spin
simple Hurwitz numbers, and arbitrary combinations of these cases, from the
analysis of the unstable (0,1)-geometry. We quantize this family of spectral
curves and obtain the Schroedinger equations for the partition function of the
corresponding Hurwitz problems. We thus confirm the conjecture for the
existence of quantum curves in these generalized Hurwitz number cases.


title: Special 2-cocycles and 3--3 Pachner move relations in Grassmann algebra

abstract:
  Grassmann-algebraic relations, corresponding naturally to Pachner move 3--3
in four-dimensional topology, are presented. They involve 2-cocycles of two
specific forms, and some more homological objects.


title: Multi-Class Detection and Segmentation of Objects in Depth

abstract:
  The quality of life of many people could be improved by autonomous humanoid
robots in the home. To function in the human world, a humanoid household robot
must be able to locate itself and perceive the environment like a human; scene
perception, object detection and segmentation, and object spatial localization
in 3D are fundamental capabilities for such humanoid robots. This paper
presents a 3D multi-class object detection and segmentation method. The
contributions are twofold. Firstly, we present a multi-class detection method,
where a minimal joint codebook is learned in a principled manner. Secondly, we
incorporate depth information using RGB-D imagery, which increases the
robustness of the method and gives the 3D location of objects -- necessary
since the robot reasons in 3D space. Experiments show that the multi-class
extension improves the detection efficiency with respect to the number of
classes and the depth extension improves the detection robustness and give
sufficient natural 3D location of the objects.


title: The cellularization principle for Quillen adjunctions

abstract:
  The Cellularization Principle states that under rather weak conditions a
Quillen adjunction of stable model categories induces a Quillen equivalence on
cellularizations provided there is a derived equivalence on cells. We give a
proof together with a range of examples. The main result here was originally
presented as an appendix of arXiv:1101.2511. However, the Cellularization
Principle has many other applications which are explored here. The material in
arXiv:1101.2511v3 will be revised to refer to this paper.


title:
Improved Cheeger's Inequality: Analysis of Spectral Partitioning
  Algorithms through Higher Order Spectral Gap

abstract:
  Let \phi(G) be the minimum conductance of an undirected graph G, and let
0=\lambda_1 <= \lambda_2 <=... <= \lambda_n <= 2 be the eigenvalues of the
normalized Laplacian matrix of G. We prove that for any graph G and any k >= 2,
  \phi(G) = O(k) \lambda_2 / \sqrt{\lambda_k}, and this performance guarantee
is achieved by the spectral partitioning algorithm. This improves Cheeger's
inequality, and the bound is optimal up to a constant factor for any k. Our
result shows that the spectral partitioning algorithm is a constant factor
approximation algorithm for finding a sparse cut if \lambda_k$ is a constant
for some constant k. This provides some theoretical justification to its
empirical performance in image segmentation and clustering problems. We extend
the analysis to other graph partitioning problems, including multi-way
partition, balanced separator, and maximum cut.


title: Minimal Nondeterministic Finite Automata and Atoms of Regular Languages

abstract:
  We examine the NFA minimization problem in terms of atomic NFA's, that is,
NFA's in which the right language of every state is a union of atoms, where the
atoms of a regular language are non-empty intersections of complemented and
uncomplemented left quotients of the language. We characterize all reduced
atomic NFA's of a given language, that is, those NFA's that have no equivalent
states. Using atomic NFA's, we formalize Sengoku's approach to NFA minimization
and prove that his method fails to find all minimal NFA's. We also formulate
the Kameda-Weiner NFA minimization in terms of quotients and atoms.


title: Measuring the Significance of the Geographic Flow of Music

abstract:
  In previous work, our results suggested that some cities tend to be ahead of
others in their musical preferences. We concluded that work by noting that to
properly test this claim, we would try to exploit the leader-follower
relationships that we identified to make predictions. Here we present the
results of our predictive evaluation. We find that information on the past
musical preferences in other cities allows a linear model to improve its
predictions by approx. 5% over a simple baseline. This suggests that at best,
previously found leader-follower relationships are rather weak.


title: Pulsar Constraints on Screened Modified Gravity

abstract:
  We calculate the rate of energy loss from compact astrophysical objects due
to a scalar field in screened modified gravity models of the chameleon, dilaton
and symmetron types. The cosmological evolution of the field results in a
time-variation of the scalar charge of screened objects implying the emission
of scalar radiation. Focusing on binary objects, this leads to an additional
decay in the orbital period complementing that due to the emission of
gravitational waves. Using the Hulse-Taylor binary pulsar, the double pulsar
PSR J0737-3039 and the pulsar-white dwarf system PSR J1738+033, we find a new
observational bound on the time variation of the scalar charge of the earth in
the Milky Way. We then translate this into a new bound on the range of the
scalar interaction in the Milky Way. Ultimately, we find that pulsar tests are
not competitive with current observational constraints.


title: The Undecidability of the Definability of Principal Subcongruences

abstract:
  For each Turing machine T, we construct an algebra A'(T) such that the
variety generated by A'(T) has definable principal subcongruences if and only
if T halts, thus proving that the property of having definable principal
subcongruences is undecidable for a finite algebra. A consequence of this is
that there is no algorithm that takes as input a finite algebra a decides
whether that algebra is finitely based.


title:
The expansion proper motions of the extraordinary giant lobes of the
  planetary nebula KjPn 8 revisited

abstract:
  The primary aim is to establish a firm value for the distance to the
extraordinary planetary nebula KjPn 8. Secondary aims are to measure the ages
of the three giant lobes of this object as well as estimate the energy in the
eruption, that caused the most energetic outflow, for comparison with that of
an intermediate luminosity optical transient (ILOT). For these purposes a
mosaic of images in the Halpha+[N II] optical emission lines has been obtained
with the new Aristarchos telescope in 2011 for comparison with the images of
the KjPn 8 giant lobes present on the POSSI-R 1954 and POSSII-R 1991 plates.
Expansion proper motions of features over this 57 yr baseline in the outflows
are present. Using these, a firm distance to KjPn 8 of 1.8 +- 0.3 kpc has been
derived for now the angle of the latest outflow to the sky has been established
from HST imagery of the nebular core. Previously, the uncertain predictions of
a bow-shock model were used for this purpose. The dynamical ages of the three
separate outflows that form the giant lobes of KjPn 8 are also directly
measured as 3200, 7200 and >= 5x10^4 yr respectively which confirms their
sequential ejection. Moreover, the kinetic energy of the youngest and most
energetic of these is measured as ~10^47 erg which is compatible with an ILOT
origin.


title:
Increase of magnetic hyperthermia efficiency due to dipolar interactions
  in low anisotropy magnetic nanoparticles : theoretical and experimental
  results

abstract:
  When magnetic nanoparticles (MNPs) are single-domain and magnetically
independent, their magnetic properties and the conditions to optimize their
efficiency in magnetic hyperthermia applications are now well-understood.
However, the influence of magnetic interactions on magnetic hyperthermia
properties is still unclear. Here, we report hyperthermia and high-frequency
hysteresis loop measurements on a model system consisting of MNPs with the same
size but a varying anisotropy, which is an interesting way to tune the relative
strength of magnetic interactions. A clear correlation between the MNP
anisotropy and the squareness of their hysteresis loop in colloidal solution is
observed : the larger the anisotropy, the smaller the squareness. Since low
anisotropy MNPs display a squareness higher than the one of magnetically
independent nanoparticles, magnetic interactions enhance their heating power in
this case. Hysteresis loop calculations of independent and coupled MNPs are
compared to experimental results. It is shown that the observed features are a
natural consequence of the formation of chains and columns of MNPs during
hyperthermia experiments: in these structures, when the MNP magnetocristalline
anisotropy is small enough to be dominated by magnetic interactions, the
hysteresis loop shape tends to be rectangular, which enhance their efficiency.
On the contrary, when MNPs do not form chains and columns, magnetic
interactions reduces the hysteresis loop squareness and the efficiency of MNPs
compared to independent ones. The present work should improve the understanding
and interpretation of magnetic hyperthermia experiments.


title: Mid-Infrared Imaging of Nearby Radio-Loud AGN

abstract:
  We present high spatial resolution MIR observations for several nearby radio
loud active galactic nuclei (RLAGN), which were obtained using the Gemini North
and South telescopes. Of the six observed objects, we detected five in the Si-2
(8.7 microns) and Si-6 (12.3 microns) filters, of which two objects show some
evidence of low level extended emission surrounding the unresolved nucleus. In
Pictor A, we also obtained an image in Qs (18.3 microns) that has a flux of
only half that seen in the Spitzer image, suggesting structure on arcsecond
scales. We also used the Si-6 (12.3 microns) flux measurement to investigate
correlation between our MIR flux and xray luminosity and compare this to
results for AGN in general. This work also forms a basis for future high
resolution imaging and spectroscopy of these objects.


title:
Solvent hydrodynamics speed up crystal nucleation in suspensions of hard
  spheres

abstract:
  We present a computer simulation study on the crystal nucleation process in
suspensions of hard spheres, fully taking into account the solvent
hydrodynamics. If the dynamics of collodial crystallization were purely
diffusive, the crystal nucleation rate densities would drop as the inverse of
the solvent viscosity. However, we observe that the nucleation rate densities
do not scale in this way, but are enhanced at high viscosities. This effect
might explain the large discrepancy between the nuclation rate densities
obtained by simulation and experiment that have reported in the literature so
far.


title: A Packetized Direct Load Control Mechanism for Demand Side Management

abstract:
  Electricity peaks can be harmful to grid stability and result in additional
generation costs to balance supply with demand. By developing a network of
smart appliances together with a quasi-decentralized control protocol, direct
load control (DLC) provides an opportunity to reduce peak consumption by
directly controlling the on/off switch of the networked appliances. This paper
proposes a packetized DLC (PDLC) solution that is illustrated by an application
to air conditioning temperature control. Here the term packetized refers to a
fixed time energy usage authorization. The consumers in each room choose their
preferred set point, and then an operator of the local appliance pool will
determine the comfort band around the set point. We use a thermal dynamic model
to investigate the duty cycle of thermostatic appliances. Three theorems are
proposed in this paper. The first two theorems evaluate the performance of the
PDLC in both transient and steady state operation. The first theorem proves
that the average room temperature would converge to the average room set point
with fixed number of packets applied in each discrete interval. The second
theorem proves that the PDLC solution guarantees to control the temperature of
all the rooms within their individual comfort bands. The third theorem proposes
an allocation method to link the results in theorem 1 and assumptions in
theorem 2 such that the overall PDLC solution works. The direct result of the
theorems is that we can reduce the consumption oscillation that occurs when no
control is applied. Simulation is provided to verify theoretical results.


title: Abelian varieties over fields of finite characteristic

abstract:
  The aim of this paper is to extend our old results about Galois action on the
torsion points of abelian varieties to the case of (finitely generated) fields
of characteristic 2.


title: A discrete analysis of metal-v belt drive

abstract:
  The metal-V belt drive includes a large number of parts which interact
between them to transmit power from the input to the output pulleys. A
compression belt composed of a great number of struts is maintained by a
tension flat belt. Power is them shared into the two belts that moves generally
in opposite directions. Due to the particular geometry of the elements and to
the great number of parts, a numerical approach achieves the global equilibrium
of the mechanism from the elementary part equilibrium. Sliding arc on each
pulley can be thus defined both for the compression and tension belts. Finally,
power sharing can be calculated as differential motion between the belts, is
defined. The first part of the paper will present the different steps of the
quasi-static mechanical analysis and their numerical implementations. Load
distributions, speed profiles and sliding angle values will be discussed. The
second part of the paper will deal to a systematic use of the computer
software. Speed ratio, transmitted torque, strut geometry and friction
coefficients effect will be analysed with the output parameter variations.
Finally, the effect pulley deformable flanges will be discussed.


title: Systems of MDS codes from units and idempotents

abstract:
  Algebraic systems are constructed from which series of maximum distance
separable (mds) codes are derived. The methods use unit and idempotent schemes.


title:
Spin-Lattice Coupling in K0.8Fe1.6Se2 and KFe2Se2: Inelastic Neutron
  Scattering and ab-initio Phonon Calculations

abstract:
  We report measurements of the temperature dependence of phonon densities of
states in K0.8Fe1.6Se2 using inelastic neutron scattering technique. While
cooling down to 150 K, a phonon peak splitting around 25 meV is observed and a
new peak appears at 31 meV. The measurements support the recent Raman and
infra-red measurements indicating a lowering of symmetry of K0.8Fe1.6Se2 upon
cooling below 250 K. Ab-initio phonon calculations have been carried out for
K0.8Fe1.6Se2 and KFe2Se2. The comparison of the phonon spectra as obtained from
the magnetic as well as non magnetic calculations show pronounced differences.
We show that in the two calculations the energy range of the vibrational
contribution from both Fe and Se are quite different. We conclude that Fe
magnetism is correlated to the phonon dynamics and it plays an important role
in stabilizing the structure of K0.8Fe1.6Se2 as well as that of KFe2Se2. The
calculations highlight the presence of low energy librational modes in
K0.8Fe1.6Se2 as compared to KFe2Se2.


title: Gluon Wavefunctions and Amplitudes on the Light-Front

abstract:
  We investigate the tree level multi-gluon components of the gluon light cone
wavefunctions in the light cone gauge keeping the exact kinematics of the gluon
emissions. We focus on the components with all helicities identical to the
helicity of the incoming gluon. The recurrence relations for the gluon
wavefunctions are derived. In the case when the virtuality of the incoming
gluon is neglected the exact form of the multi-gluon wavefunction as well as
the fragmentation function is obtained. Furthermore we analyze the 2 to N
tree-level gluon scattering in the framework of light-front perturbation theory
and we demonstrate that the amplitude for this process can be obtained from the
1 to N+1 gluon wavefunction. Finally, we demonstrate that our results for
selected helicity configurations are equivalent to the Parke-Taylor amplitudes.


title: No temperature fluctuations in the giant HII region H 1013

abstract:
  While collisionally excited lines in HII regions allow one to easily probe
the chemical composition of the interstellar medium in galaxies, the possible
presence of important temperature fluctuations casts some doubt on the derived
abundances. To provide new insights into this question, we have carried out a
detailed study of a giant HII region, H 1013, located in the galaxy M101, for
which many observational data exist and which has been claimed to harbour
temperature fluctuations at a level of t^2 = 0.03-0.06. We have first
complemented the already available optical observational datasets with a
mid-infrared spectrum obtained with the Spitzer Space Telescope. Combined with
optical data, this spectrum provides unprecedented information on the
temperature structure of this giant HII region. A preliminary analysis based on
empirical temperature diagnostics suggests that temperature fluctuations should
be quite weak. We have then performed a detailed modelling using the pyCloudy
package based on the photoionization code Cloudy. We have been able to produce
photoionization models constrained by the observed Hb surface brightness
distribution and by the known properties of the ionizing stellar population
than can account for most of the line ratios within their uncertainties. Since
the observational constraints are both strong and numerous, this argues against
the presence of significant temperature fluctuations in H 1013. The oxygen
abundance of our best model is 12 + log O/H = 8.57, as opposed to the values of
8.73 and 8.93 advocated by Esteban et al. (2009) and Bresolin (2007),
respectively, based on the significant temperature fluctuations they derived.
However, our model is not able to reproduce the intensities of the oxygen
recombination lines . This cannot be attributed to observational uncertainties
and requires an explanation other than temperature fluctuations.


title:
Magellan/MMIRS near-infrared multi-object spectroscopy of nebular
  emission from star forming galaxies at 2<z<3

abstract:
  To investigate the ingredients, which allow star-forming galaxies to present
Lyalpha line in emission, we studied the kinematics and gas phase metallicity
(Z) of the interstellar medium. We used multi-object NIR spectroscopy with
Magellan/MMIRS to study nebular emission from z=2-3 star-forming galaxies
discovered in 3 MUSYC fields. We detected emission lines from four active
galactic nuclei and 13 high-z star-forming galaxies, including Halpha lines
down to a flux of 4.E-17 erg/sec/cm^2. This yielded 7 new redshifts. The most
common emission line detected is [OIII]5007, which is sensitive to Z. We were
able to measure Z for 2 galaxies and to set upper(lower) limits for another
2(2). The Z values are consistent with 0.3<Z/Zsun<1.2. Comparing the Lyalpha
central wavelength with the systemic redshift, we find
Delta_v(Lyalpha-[OIII])=70-270 km/sec. High-redshift star-forming galaxies,
Lyalpha emitting (LAE) galaxies, and Halpha emitters appear to be located in
the low mass, high star-formation rate (SFR) region of the SFR versus stellar
mass diagram, confirming that they are experiencing burst episodes of star
formation, which are building up their stellar mass. Their Zs are consistent
with the relation found for z<2.2 galaxies in the Z versus stellar mass plane.
The measured Delta_v(Lyalpha-[OIII]) values imply that outflows of material,
driven by star formation, could be present in the z=2-3 LAEs of our sample.
Comparing with the literature, we note that galaxies with lower Z than ours are
also characterized by similar Delta_v(Lyalpha-[OIII]) velocity offsets. Strong
[OIII] is detected in many Lyalpha emitters. Therefore, we propose the
Lyalpha/[OIII] flux ratio as a tool for the study of high-z galaxies; while
influenced by Z, ionization, and Lyalpha radiative transfer in the ISM, it may
be possible to calibrate this ratio to primarily trace one of these effects.


title:
Fields and Flares: Understanding the Complex Magnetic Topologies of
  Solar Active Regions

abstract:
  Sunspots are regions of decreased brightness on the visible surface of the
Sun (photosphere) that are associated with strong magnetic fields. They have
been found to be locations associated with solar flares, which occur when
energy stored in sunspot magnetic fields is suddenly released. The processes
involved in flaring and the link between sunspot magnetic fields and flares is
still not fully understood, and this thesis aims to gain a better understanding
of these topics. The magnetic field evolution of a number of sunspot regions is
examined using high spatial resolution data from the Hinode spacecraft. The
research presented in this thesis gives insight into both photospheric and
coronal magnetic field evolution of flaring regions. Significant increases in
vertical field strength, current density, and field inclination angle towards
the vertical are observed in the photosphere just hours before a flare occurs,
which is on much shorter timescales than previously studied. First observations
of spatial changes in field inclination across a magnetic neutral line
(generally believed to be a typical source region of flares) are also
discovered. 3D magnetic field extrapolation methods are used to study the
coronal magnetic field, using the photospheric magnetic field data as a
boundary condition. Magnetic energy and free magnetic energy are observed to
increase significantly a few hours before a flare, and decrease afterwards,
which is a similar trend to the photospheric field parameter changes observed.
Evidence of partial Taylor relaxation is also detected after a flare, as
predicted by several previous studies. The results outlined in this thesis show
that this particular field of research is vital in furthering our understanding
of the magnetic nature of sunspots and its link to flare processes.


title:
The effects of dust on the derived photometric parameters of disks and
  bulges in spiral galaxies

abstract:
  We present results of a study to quantify the effects of dust on the derived
photometric parameters of disks (old stellar disks and young stellar disks) and
bulges: disk scale-lengths, axis-ratios, central surface-brightness, bulge
effective radii and Sersic indexes. The changes in the derived photometric
parameters from their intrinsic values (as seen in the absence of dust) were
obtained by fitting simulated images of disks and bulges produced using
radiative transfer calculations and the model of Popescu et al. (2011). The
fits to the simulations were performed using GALFIT 3.0.2 data analysis
algorithm and the fitted models were the commonly used infinitely thin disks
described by exponential, general Sersic and de Vaucouleurs distributions. We
find the young stellar disks to suffer the most severe variation in the
photometric parameters due to dust effects. In this context we also present
corrections for narrow line (Balmer line) images. Old stellar disks are also
significantly affected by dust, in particular when fits are performed with
exponential functions. The photometric parameters of bulges are to a lesser
extent affected by dust. We also find that the variation of dust corrections
with face-on dust opacity and inclination is similar for bulges with different
intrinsic stellar emissivities (different Sersic index), with differences
manifesting only close to edge-on orientations of the disk. Dust corrections
for bulges are found to be insensitive to the choice of the truncation radius
and ellipticity of the bulge. All corrections are listed in the Appendix and
made available in electronic format.


title:
Plasmonic finite-thickness metal-semiconductor-metal waveguide as
  ultra-compact modulator

abstract:
  We propose a plasmonic modulator with semiconductor gain material for
optoelectronic integrated circuits. We analyze properties of a finite-thickness
metal-semiconductor-metal (F-MSM) waveguide to be utilized as an ultra-compact
and fast plasmonic modulator. The InP-based semiconductor core allows
electrical control of signal propagation. By pumping the core we can vary the
gain level and thus the transmittance of the whole system. The study of the
device was made using both analytical approaches for planar two-dimensional
case as well as numerical simulations for finite-width waveguides. We analyze
the eigenmodes of the F-MSM waveguide, propagation constant, confinement
factor, Purcell factor, absorption coefficient, and extinction ratio of the
structure. We show that using thin metal layers instead of thick ones we can
obtain higher extinction ratio of the device.


title:
Logarithmic scaling of the collapse in the critical Keller-Segel
  equation

abstract:
  A reduced Keller-Segel equation (RKSE) is a parabolic-elliptic system of
partial differential equations which describes bacterial aggregation and the
collapse of a self-gravitating gas of brownian particles. We consider RKSE in
two dimensions, where solution has a critical collapse (blow-up) if the total
number of bacteria exceeds a critical value. We study the self-similar
solutions of RKSE near the blow-up point. Near the collapse time, $t=t_c$, the
critical collapse is characterized by the $L\propto (t_c-t)^{1/2}$ scaling law
with logarithmic modification, where $L$ is the spatial width of collapsing
solution. We develop an asymptotic perturbation theory for these modifications
and show that the resulting scaling agrees well with numerical simulations. The
quantitative comparison of the theory and simulations requires to take into
account several terms of the perturbation series.


title:
Reflected Spectrally Negative Stable Processes and their Governing
  Equations

abstract:
  This paper explicitly computes the transition densities of a spectrally
negative stable process with index greater than one, reflected at its infimum.
First we derive the forward equation using the theory of sun-dual semigroups.
The resulting forward equation is a boundary value problem on the positive
half-line that involves a negative Riemann-Liouville fractional derivative in
space, and a fractional reflecting boundary condition at the origin. Then we
apply numerical methods to explicitly compute the transition density of this
space-inhomogeneous Markov process, for any starting point, to any desired
degree of accuracy. Finally, we discuss an application to fractional Cauchy
problems, which involve a positive Caputo fractional derivative in time.


title: Principal Hodge representations

abstract:
  We study Hodge representations of absolutely simple Q-algebraic groups with
Hodge numbers h = (1,1,...,1). For those groups that are not of type A, we give
a classification of the R-irreducible representations; a similar classification
for type A does not seem possible.


title: Information as Distinctions: New Foundations for Information Theory

abstract:
  The logical basis for information theory is the newly developed logic of
partitions that is dual to the usual Boolean logic of subsets. The key concept
is a "distinction" of a partition, an ordered pair of elements in distinct
blocks of the partition. The logical concept of entropy based on partition
logic is the normalized counting measure of the set of distinctions of a
partition on a finite set--just as the usual logical notion of probability
based on the Boolean logic of subsets is the normalized counting measure of the
subsets (events). Thus logical entropy is a measure on the set of ordered
pairs, and all the compound notions of entropy (join entropy, conditional
entropy, and mutual information) arise in the usual way from the measure (e.g.,
the inclusion-exclusion principle)--just like the corresponding notions of
probability. The usual Shannon entropy of a partition is developed by replacing
the normalized count of distinctions (dits) by the average number of binary
partitions (bits) necessary to make all the distinctions of the partition.


title: Transport from the Recycler Ring to the Antiproton Source Beamlines

abstract:
  In the post-Nova era, the protons are directly transported from the Booster
ring to the Recycler ring rather than the Main Injector. For Mu2e and g-2
project, the Debuncher ring will be modified into a Delivery ring to deliver
the protons to both Mu2e and g-2 experiemnts. Therefore, It requires the
transport of protons from the Recycler Ring to the Delivery ring. A new
transfer line from the Recycler ring to the P1 beamline will be constructed to
transport proton beam from the Recycler Ring to existing Antiproton Source
beamlines. This new beamline provides a way to deliver 8 GeV kinetic energy
protons from the Booster to the Delivery ring, via the Recycler, using existing
beam transport lines, and without the need for new civil construction. This
paper presents the Conceptual Design of this new beamline.


title: Accelerating fronts in semilinear wave equations

abstract:
  We study dynamics of interfaces in solutions of the equation $\epsilon \Box u
+ \frac 1 \epsilon f_\epsilon(u)=0$, for $f_\epsilon$ of the form
$f_\epsilon(u) = (u^2-1)(2u- \epsilon\kappa)$, for $\kappa\in {\mathbb R}$, as
well as more general, but qualitatively similar, nonlinearities. We consider
equations of this form both in $(1+n)$-dimensional Minkowski space, $n\ge 1$,
and on certain more general Lorentzian manifolds, and we prove that for
suitable initial data, solutions exhibit interfaces that sweep out timelike
hypersurfaces of mean curvature proportional to $\kappa$. In particular, in 1
dimension these interfaces behave like a relativistic point particle subject to
constant acceleration.


title: Routing quantum information in spin chains

abstract:
  Two different models for performing efficiently routing of a quantum state
are presented. Both cases involve an XX spin chain working as data bus and
additional spins that play the role of sender and receivers, one of which is
selected to be the target of the quantum state transmission protocol via a
coherent quantum coupling mechanism making use of local/global magnetic fields.
Quantum routing is achieved, in the first of the models considered, by weakly
coupling the sender and the receiver to the data bus. In the second model,
strong magnetic fields acting on additional spins located between the
sender/receiver and the data bus allow us to perform high fidelity routing.


title:
Maximum likelihood estimators for the extreme value index based on the
  block maxima method

abstract:
  The maximum likelihood method offers a standard way to estimate the three
parameters of a generalized extreme value (GEV) distribution. Combined with the
block maxima method, it is often used in practice to assess the extreme value
index and normalization constants of a distribution satisfying a first order
extreme value condition, assuming implicitely that the block maxima are exactly
GEV distributed. This is unsatisfactory since the GEV distribution is a good
approximation of the block maxima distribution only for blocks of large size.
The purpose of this paper is to provide a theoretical basis for this
methodology. Under a first order extreme value condition only, we prove the
existence and consistency of the maximum likelihood estimators for the extreme
value index and normalization constants within the framework of the block
maxima method.


title:
On the Complexity of Computing Gr\"obner Bases for Quasi-homogeneous
  Systems

abstract:
  Let $\K$ be a field and $(f_1, \ldots, f_n)\subset \K[X_1, \ldots, X_n]$ be a
sequence of quasi-homogeneous polynomials of respective weighted degrees $(d_1,
\ldots, d_n)$ w.r.t a system of weights $(w_{1},\dots,w_{n})$. Such systems are
likely to arise from a lot of applications, including physics or cryptography.
We design strategies for computing Gr\"obner bases for quasi-homogeneous
systems by adapting existing algorithms for homogeneous systems to the
quasi-homogeneous case. Overall, under genericity assumptions, we show that for
a generic zero-dimensional quasi-homogeneous system, the complexity of the full
strategy is polynomial in the weighted B\'ezout bound $\prod_{i=1}^{n}d_{i} /
\prod_{i=1}^{n}w_{i}$. We provide some experimental results based on generic
systems as well as systems arising from a cryptography problem. They show that
taking advantage of the quasi-homogeneous structure of the systems allow us to
solve systems that were out of reach otherwise.


title: Multiplicities of graded families of linear series and ideals

abstract:
  We give simple necessary and sufficient conditions on projective schemes over
a field k for asymptotic limits of the growth of all graded linear series of a
fixed Kodaira-Iitaka dimension to exist. We also give necessary and sufficient
conditions on a local ring R of dimension d for the limit
\lim_{i\rightarrow\infty}\frac{\ell_R(R/I_n)}{n^d} to exist whenever \{I_n\} is
a graded family of m_R-primary ideals. We give a number of applications.


title: Origin of the dense core mass function in contracting filaments

abstract:
  Mass functions of starless dense cores (CMFs) may arise from contraction and
dispersal of core-forming filaments. In an illustrative model, a filament
contracts radially by self-gravity, increasing the mass of its cores. During
this contraction, FUV photoevaporation and ablation by shocks and winds
disperse filament gas and limit core growth. The stopping times of core growth
are described by a waiting-time distribution. The initial filament column
density profile and the resulting CMF each match recent Herschel observations
in detail. Then low-mass cores have short growth ages and arise from the
innermost filament gas, while massive cores have long growth ages and draw from
more extended filament gas. The model fits the initial density profile and CMF
best for mean core density 2 10^4 cm^-3 and filament dispersal time scale 0.5
Myr. Then the typical core mass, radius, mean column density, and contraction
speed are respectively 0.8 solar masses, 0.06 pc, 6 10^21 cm^-2, and 0.07 km
s^-1, also in accord with observed values.


title: Symmetry energy from nuclear multifragmentation

abstract:
  The ratio of symmetry energy coefficient to temperature $C_{sym}/T$ is
extracted from different prescriptions using the isotopic as well as the
isobaric yield distributions obtained in different projectile fragmentation
reactions. It is found that the values extracted from our theoretical
calculation agree with those extracted from the experimental data but they
differ very much from the input value of the symmetry energy used. The best
possible way to deduce the value of the symmetry energy coefficient is to use
the fragment yield at the breakup stage of the reaction and it is better to use
the grand canonical model for the fragmentation analysis. This is because the
formulas that are used for the deduction of the symmetry energy coefficient are
all derived in the framework of the grand canonical ensemble which is valid
only at the break-up (equilibrium) condition. The yield of "cold" fragments
either from the theoretical models or from experiments when used for extraction
of the symmetry energy coefficient using these prescriptions might lead to the
wrong conclusion.


title:
When can gravitational-wave observations distinguish between black holes
  and neutron stars?

abstract:
  Gravitational-wave observations of compact binaries have the potential to
uncover the distribution of masses and angular momenta of black holes and
neutron stars in the universe. The binary components' physical parameters can
be inferred from their effect on the phasing of the gravitational-wave signal,
but a partial degeneracy between the components' mass ratio and their angular
momenta limits our ability to measure the individual component masses. At the
typical signal amplitudes expected by the Advanced Laser Interferometer
Gravitational-wave Observatory (signal-to-noise ratios between 10 and 20), we
show that it will in many cases be difficult to distinguish whether the
components are neutron stars or black holes. We identify when the masses of the
binary components could be unambiguously measured outside the range of current
observations: a system with a chirp mass $\mathcal{M} \le 0.871 $ M$_\odot$
would unambiguously contain the smallest-mass neutron star observed, and a
system with $\mathcal{M} \ge 2.786 \Msun$ must contain a black hole. However,
additional information would be needed to distinguish between a binary
containing two 1.35 M$_\odot$ neutron stars and an exotic
neutron-star--black-hole binary. We also identify those configurations that
could be unambiguously identified as black-hole binaries, and show how the
observation of an electromagnetic counterpart to a neutron-star--black-hole
binary could be used to constrain the black-hole spin.


title: Earth tides in MacDonald's model

abstract:
  We expand the equations used in MacDonald's 1964 theory and Fourier analyze
the tidal variations of the height at one point on the Earth surface, and also
the tidal potential at such point. It is shown that no intrinsic law is
relating the lag of the tide components to their frequencies. In other words,
no simple rheology is being intrinsically fixed by MacDonald's equations. The
same is true of the modification proposed by Singer(1968). At variance with
these two cases, the modification proposed by Williams and Efroimsky (2012) fix
the standard Darwin rheology in which the lags are proportional to the
frequencies and their model is, in this sense, equivalent to Mignard's 1979
formulation of Darwin's theory.


title: Summary of Fermilab's Recycler Electron Cooler Operation and Studies

abstract:
  Fermilab's Recycler ring was used as a storage ring for accumulation and
subsequent manipulations of 8-GeV antiprotons destined for the Tevatron
collider. To satisfy these missions, a unique electron cooling system was
designed, developed and successfully implemented. The most important features
that distinguish the Recycler cooler from other existing electron coolers are
its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak
continuous longitudinal magnetic field in the cooling section (~100 G), and
lumped focusing elsewhere. With the termination of the collider operation at
Fermilab, the cooler operation was also terminated. In this article, we will
summarize the experience of commissioning, optimizing and running this unique
machine over the 6 years of its existence.


title:
Mechanical Design of a High Energy Beam Absorber for the Advanced
  Superconducting Test Accelerator (ASTA) at Fermilab

abstract:
  A high energy beam absorber has been built for the Advanced Superconducting
Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration,
an electron beam will be accelerated through 3 TTF-type or ILC-type RF
cryomodules to an energy of 750MeV. The electron beam will be directed to one
of multiple downstream experimental and diagnostic beam lines and then
deposited in one of two beam absorbers. The facility is designed to accommodate
up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the
driving design condition for the beam absorbers. The beam absorbers consist of
water-cooled graphite, aluminum and copper layers contained in a Helium-filled
enclosure. This paper describes the mechanical implementation of the beam
absorbers, with a focus on thermal design and analysis. In addition, the
potential for radiation-induced degradation of the graphite is discussed.


title:
Stratified Graphene-Noble Metal Systems for Low-Loss Plasmonics
  Applications

abstract:
  We propose a composite layered structure for tunable, low-loss plasmon
resonances, which con- sists of a noble-metal thin film coated in graphene and
supported on a hexagonal boron nitride (hBN) substrate. We calculate electron
energy loss spectra (EELS) for these structures, and nu- merically demonstrate
that bulk plasmon losses in noble-metal films can be significantly reduced, and
surface coupling enhanced, through the addition of a graphene coating and the
wide-bandgap hBN substrate. Silver films with a trilayer graphene coating and
hBN substrate demonstrated sur- face plasmon-dominant spectral profiles for
metallic layers as thick as 34 nm. A continued-fraction expression for the
effective dielectric function, based on a specular reflection model which
includes boundary interactions, is used to systematically demonstrate plasmon
peak tunability for a variety of configurations. Variations include substrate,
plasmonic metal, and individual layer thickness for each material. Mesoscale
calculation of EELS is performed with individual layer dielectric functions as
input to the effective dielectric function calculation, from which the loss
spectra are directly determined.

categories: cond-mat.mes-hall cond-mat.mtrl-sci physics.comp-ph physics.optics


title: Nonlinear Partially Massless from Massive Gravity?

abstract:
  We show that consistent nonlinear Partially Massless models cannot be
obtained starting from "f-g" massive gravity, with "f" the embedding de Sitter
space. The obstruction, which is also the source of f-g acausality, is the very
same fifth constraint that removes the notorious sixth ghost excitation. Here,
however, it blocks extension of the mass to cosmological background tuned gauge
invariance that took away the helicity zero mode at linear level. Separately,
our methods allow us to almost complete the class of acausal f-g models.


title:
Nodal superconductivity in isovalently substituted
  SrFe$_2$(As$_{1-x}$P$_{x}$)$_2$ pnictide superconductor at the optimal
  doping, $x=$0.35

abstract:
  Temperature-dependent London penetration depth, $\lambda(T)$, was measured in
optimally - doped, $x=$0.35, as-grown ($T_c \approx$25 K,
RRR=$\rho(300K)/\rho(T_c)$=4.5) and annealed ($T_c \approx$35 K, RRR=6.4)
single crystals of SrFe$_2$(As$_{1-x}$P$_{x}$)$_2$ iron - based superconductor.
Annealing increases the RRR and decreases the absolute value of the London
penetration depth from $\lambda(0) = 300 \pm 10$ nm in as-grown sample to
$\lambda(0) = 275 \pm 10$ nm. At low temperatures, $\lambda(T) \sim T$
indicating superconducting gap with line nodes. Analysis of the full -
temperature range superfluid density is consistent with the line nodes, but
differs from the simple single - gap $d-$wave. The observed behavior is very
similar to that of BaFe$_2$(As$_{1-x}$P$_{x}$)$_2$, showing that isovalently
substituted pnictides are inherently different from the charge - doped
materials.


title: Growth tightness for groups with contracting elements

abstract:
  We establish growth tightness for a class of groups acting geometrically on a
geodesic metric space and containing a contracting element. As a consequence,
any group with nontrivial Floyd boundary are proven to be growth tight with
respect to word metrics. In particular, all non-elementary relatively
hyperbolic group are growth tight. This generalizes previous works of
Arzhantseva-Lysenok and Sambusetti. Another interesting consequence is that
CAT(0) groups with rank-1 elements are growth tight with respect to
CAT(0)-metric.


title: Non-Markovian Equilibration Controlled by Symmetry Breaking

abstract:
  We study the effects of symmetry breaking on non-Markovian dynamics in
various system-bath arrangements. It is shown that by breaking certain
symmetries features signaling non-Markovian time evolution disappear within a
finite time t_{g}. We demonstrate numerically that the scaling of t_{g} with
the symmetry breaking strength is different for various types of symmetry. We
provide a mathematical explanation for these differences related to the
spectrum of the total system-bath Hamiltonian and provide arguments that the
scaling properties of t_{g} should be universal.


title: Brauer Theory for Profinite Groups

abstract:
  Brauer Theory for a finite group can be viewed as a method for comparing the
representations of the group in characteristic 0 with those in prime
characteristic. Here we generalize much of the machinery of Brauer theory to
the setting of profinite groups. By regarding Grothendieck groups as functors
we describe corresponding Grothendieck groups for profinite groups, and
generalize the decomposition map, regarded as a natural transformation. We
discuss characters and Brauer characters for profinite groups. We give a
functorial description of the block theory of a profinite group. We finish with
a method for computing the Cartan matrix of a finite group $G$ given the Cartan
matrix for a quotient of $G$ by a normal $p$-subgroup.


title: Physical Parameters for RR Lyrae Stars in the SDSS Filter System

abstract:
  We present a calibration of the metallicity and physical parameters
(temperature, luminosity, gravity, mass, radius) for RR Lyrae stars using the
ugriz SDSS photometric system. Our work is based on calculations of synthetic
horizontal branches (HBs), fully taking into account evolutionary effects for a
wide range in metallicities and HB morphologies. We provide analytical fits
that are able to provide all quantities mentioned with very high (internal)
precision, based solely on mean SDSS magnitudes and colors.


title: Clouds and Hazes in Exoplanet Atmospheres

abstract:
  Clouds and hazes are commonplace in the atmospheres of solar system planets
and are likely ubiquitous in the atmospheres of extrasolar planets as well.
Clouds affect every aspect of a planetary atmosphere, from the transport of
radiation, to atmospheric chemistry, to dynamics and they influence - if not
control - aspects such as surface temperature and habitability. In this review
we aim to provide an introduction to the role and properties of clouds in
exoplanetary atmospheres. We consider the role clouds play in influencing the
spectra of planets as well as their habitability and detectability. We briefly
summarize how clouds are treated in terrestrial climate models and consider the
far simpler approaches that have been taken so far to model exoplanet clouds,
the evidence for which we also review. Since clouds play a major role in the
atmospheres of certain classes of brown dwarfs we briefly discuss brown dwarf
cloud modeling as well. We also review how the scattering and extinction
efficiencies of cloud particles may be approximated in certain limiting cases
of small and large particles in order to facilitate physical understanding.
Since clouds play such important roles in planetary atmospheres, cloud modeling
may well prove to be the limiting factor in our ability to interpret future
observations of extrasolar planets.


title:
A Higgs-Like Scalar With Mixed-Parity and Standard-Model-Like Couplings
  Could be Further Evidence for Underlying Massless SU(5) Unification

abstract:
  The bound-state S-Matrix of QUD (SU(5) gauge theory with massless left-handed
5 + 15 + 40 + 45* fermions) might underly the success of the Standard Model.
The dynamical role of the QUD top quark leads to two Higgs-like scalar
resonances, the eta_6 - which reproduces Standard Model top events, and the
eta_3 - which could have a mass ~ 125 GeV. The participation of the weak
interaction in the dynamics implies the resonances are not parity eigenstates
and so should have pseudoscalar and scalar electroweak couplings. Also, a
tree-unitarity condition could hold - in part because of the closeness of the
electroweak physical amplitudes to perturbation theory, and - in part because
of the intimate relation with regge behavior. This would imply that the
combined physical couplings of the two resonances are comparable to those of
the Standard Model Higgs boson. Unlike the isolated Standard Model, the
underlying unification of QUD implies there will be no LHC "nightmare scenario"
and that, instead, a broad, extensive, experimental program should, eventually,
be implemented.


title:
Quantum oscillations of the specific heat in d-wave superconductors with
  loop current order

abstract:
  We report numerical results of quantum oscillations of the specific heat in
the vortex state of a $d_{x^2-y^2}$-wave superconductor in the presence of loop
current order, which gives rise to Fermi pockets coexisting with nodal
$d_{x^2-y^2}$-wave superconductivity. Within a lattice tight-binding model, we
find that in an intermediate temperature range, the oscillations seem to
approximately follow Onsager relation with an effective charge comparable to
the electric charge. However, the quasiparticle spectrum does not resemble
Landau levels. In order to understand the origin of the oscillations, we also
perform Franz-Tesanovic transformation in the presence of the loop order and
find that in addition to scalar and Berry potentials, one component of the
gauge invariant superfluid velocity couples to the low lying Dirac particles as
a component of a vector potential. The magnetic field associated with this
vector potential vanishes on average but is highly non-uniform in the magnetic
unit cell. We also compare the results with the model without the loop order
but with Zeeman-like coupling which also induces Fermi pockets in the
superconducting state.


title:
Diophantine approximation and the geometry of limit sets in Gromov
  hyperbolic metric spaces

abstract:
  In this paper, we provide a complete theory of Diophantine approximation in
the limit set of a group acting on a Gromov hyperbolic metric space. This
summarizes and completes a long line of results by many authors, from
Patterson's classic '76 paper to more recent results of Hersonsky and Paulin
('02, '04, '07). Concrete examples of situations we consider which have not
been considered before include geometrically infinite Kleinian groups,
geometrically finite Kleinian groups where the approximating point is not a
fixed point of the group, and groups acting on infinite-dimensional hyperbolic
space. Moreover, in addition to providing much greater generality than any
prior work of which we are aware, our results also give new insight into the
nature of the connection between Diophantine approximation and the geometry of
the limit set within which it takes place. Two results are also contained here
which are purely geometric: a generalization of a theorem of Bishop and Jones
('97) to Gromov hyperbolic metric spaces, and a proof that the uniformly radial
limit set of a group acting on a proper geodesic Gromov hyperbolic metric space
has zero Patterson--Sullivan measure unless the group is quasiconvex-cocompact.
The latter is an application of a Diophantine theorem.


title:
Shift in weak phase $\gamma$ due to CP asymmetries in $D$ decays to two
  pseudoscalar mesons

abstract:
  A difference of several tenths of a percent has been observed between the
direct CP asymmetries of $D^0\to K^+K^-$ and $D^0\to \pi^+\pi^-$. It has been
noted recently that CP asymmetries in such singly-Cabibbo-suppressed (SCS)
decays can affect the determination of the weak phase $\gamma$ using the
Gronau-London-Wyler method of comparing rates for $B^+ \to D K^+$ and $B^- \to
D K^-$, where $D$ is a superposition of $D^0$ and $\od$ decaying to a CP
eigenstate. Using an analysis of the CP asymmetries in SCS decays based on a $c
\to u$ penguin amplitude with standard model weak phase but enhanced by
CP-conserving strong interactions, we estimate typical shifts in $\gamma$ of
several degrees and pinpoint measurements which would reduce uncertainties to
an acceptable level.


title: Division Algebras With Infinite Genus

abstract:
  To what extent does the maximal subfield spectrum of a division algebra
determine the isomorphism class of that algebra? It has been shown that over
some fields a quaternion division algebra's isomorphism class is largely if not
entirely determined by its maximal subfield spectrum. However in this paper, we
show that there are fields for which the maximal subfield spectrum says little
to nothing about a quaternion division algebra's isomorphism class. We give an
explicit construction of a division algebra with infinite genus. Along the way
we introduce the notion of a "linking field extension," which we hope will be
of independent interest. We go on to show that there exists a field K for which
(1) there are infinitely many nonisomorphic quaternion division algebras with
center K, and (2) any two quaternion division algebra with center K are
pairwise weakly isomorphic. In fact we show that there are infinitely many
nonisomorphic fields satisfying these two conditions.


title:
Resonance projectors and asymptotics for r-normally hyperbolic trapped
  sets

abstract:
  We prove an asymptotic formula for the number of scattering resonances in a
strip near the real axis when the trapped set is r-normally hyperbolic with r
large and a pinching condition on the normal expansion rates holds. Our
dynamical assumptions are stable under smooth perturbations and motivated by
the setting of black holes. The key tool is a Fourier integral operator which
microlocally projects onto the resonant states in the strip. In addition to
Weyl law, this operator provides new information about microlocal concentration
of resonant states.


title:
Dominant Superconducting Fluctuations in the One-Dimensional Extended
  Holstein-Extended Hubbard model

abstract:
  The search for realistic one-dimensional (1D) models that exhibit dominant
superconducting (SC) fluctuations effects has a long history. In these 1D
systems, the effects of commensurate band fillings--strongest at
half-filling--and electronic repulsions typically lead to a finite charge gap
and the favoring of insulating density wave ordering over superconductivity.
Accordingly, recent proposals suggesting a gapless metallic state in the
Holstein-Hubbard (HH) model, possibly superconducting, have generated
considerable interest and controversy, with the most recent work demonstrating
that the putative dominant superconducting state likely does not exist. In this
paper we study a model with non-local electron-phonon interactions, in addition
to electron-electron interactions, this model unambiguously possesses dominant
superconducting fluctuations at half filling in a large region of parameter
space. Using both the numerical multi-scale functional renormalization group
for the full model and an analytic conventional renormalization group for a
bosonized version of the model, we demonstrate the existence of dominant
superconducting (SC) fluctuations. These dominant SC fluctuations arise because
the spin-charge coupling at high energy is weakened by the non-local
electron-phonon interaction and the charge gap is destroyed by the resultant
suppression of the Umklapp process. The existence of the dominant SC pairing
instability in this half-filled 1D system suggests that non-local
boson-mediated interactions may be important in the superconductivity observed
in the organic superconductors.


title: Functional inequalities involving modified Struve functions

abstract:
  In this paper our aim is to prove some monotonicity and convexity results for
the modified Struve function of the second kind by using its integral
representation. Moreover, as consequences of these results, we present some
functional inequalities (like Tur\'an type inequalities) as well as lower and
upper bounds for modified Struve function of the second kind and its
logarithmic derivative.


title: Kitaev honeycomb and other exotic spin models with polar molecules

abstract:
  We show that ultracold polar molecules pinned in an optical lattice can be
used to access a variety of exotic spin models, including the Kitaev honeycomb
model. Treating each molecule as a rigid rotor, we use DC electric and
microwave fields to define superpositions of rotational levels as effective
spin degrees of freedom, while dipole-dipole interactions give rise to
interactions between the spins. In particular, we show that, with sufficient
microwave control, the interaction between two spins can be written as a sum of
five independently controllable Hamiltonian terms proportional to the five
rank-2 spherical harmonics Y_{2,q}(theta,phi), where (theta,phi) are the
spherical coordinates of the vector connecting the two molecules. To
demonstrate the potential of this approach beyond the simplest examples studied
in [S. R. Manmana et al., arXiv:1210.5518v2], we focus on the realization of
the Kitaev honeycomb model, which can support exotic non-Abelian anyonic
excitations. We also discuss the possibility of generating spin Hamiltonians
with arbitrary spin S, including those exhibiting SU(N=2S+1) symmetry.

categories: cond-mat.quant-gas cond-mat.str-el physics.atom-ph quant-ph


title:
Transition Magnetic Moments and Collective Neutrino
  Oscillations:Three-Flavor Effects and Detectability

abstract:
  We demonstrate the non-negligible effect of transition magnetic moments on
three-flavor collective oscillations of Majorana neutrinos in the core of
type-II supernovae, within the single-angle approximation. We argue that data
from a galactic supernova in conjunction with terrestrial experiments can
potentially give us clues about the non-zero nature of neutrino transition
magnetic moments if these are Majorana fermions, even if their values are as
small as those predicted by the Standard Model augmented by nonzero neutrino
Majorana masses.


title: Magnetic flux paradigm for radio-loudness of AGN

abstract:
  We argue that the magnetic flux threading the black hole, rather than black
hole spin or Eddington ratio, is the dominant factor in launching powerful jets
and thus determining the radio loudness of active galactic nuclei (AGN). Most
AGN are radio quiet because the thin accretion disks that feed them are
inefficient in depositing magnetic flux close to the black hole. Flux
accumulation is more likely to occur during a hot accretion (or thick disk)
phase, and we argue that radio-loud quasars and strong emission-line radio
galaxies occur only when a massive, cold accretion event follows an episode of
hot accretion. Such an event might be triggered by the merger of a giant
elliptical galaxy with a disk galaxy.
  This picture supports the idea that flux accumulation can lead to the
formation of a so-called magnetically choked accretion flow (MCAF). The large
observed range in radio loudness reflects not only the magnitude of the flux
pressed against the black hole, but also the decrease in UV flux from the disk,
due to its disruption by the "magnetosphere" associated with the accumulated
flux. While the strongest jets result from the secular accumulation of flux,
moderate jet activity can also be triggered by fluctuations in the magnetic
flux deposited by turbulent, hot inner regions of otherwise thin accretion
disks, or by the dissipation of turbulent fields in accretion disk coronae.
These processes could be responsible for jet production in Seyferts and
low-luminosity AGN, as well as jets associated with X-ray binaries.


title:
Topological Zero-Energy Modes in Gapless Commensurate
  Aubry-Andr\'e-Harper Models

abstract:
  The Aubry-Andr\'e or Harper (AAH) model has been the subject of extensive
theoretical research in the context of quantum localization. Recently, it was
shown that one-dimensional quasicrystals described by the incommensurate AAH
model has a nontrivial topology. In this Letter, we show that the commensurate
off-diagonal AAH model is topologically nontrivial in the gapless regime and
supports zero-energy edge modes. Unlike the incommensurate case, the nontrivial
topology in the off-diagonal AAH model is attributed to the topological
properties of the one-dimensional Majorana chain. We discuss the feasibility of
experimental observability of our predicted topological phase in the
commensurate AAH model.


title:
Spatially resolved star formation histories of nearby galaxies: evidence
  for episodic star formation in discs

abstract:
  We use long-slit spectroscopy from Moran et al. to study the radial
dependence of the recent star formation histories of nearby galaxies with
stellar masses greater than 10^10M_sun. We fit stellar population models to the
combination of SSFR, D4000 and Hdelta_A and show that many galaxies have Balmer
absorption line equivalent widths that require recent short-lived episodes or
bursts of star formation. The fraction of galaxies that have experienced
episodic rather than continuous star formation is highest for late-type
galaxies with low stellar masses. In these systems, bursts occur both in the
inner and outer regions of the galaxy. The fraction of stars formed in a single
burst episode is typically around 15% of the total stellar mass in the inner
regions of the galaxy and around 5% of the mass in the outer regions. When we
average over the population, we find that such bursts contribute around a half
of the total mass in stars formed in the last 2 Gyr. In massive galaxies,
bursts occur predominantly in the outer disk. Around a third of all massive,
bulge-dominated galaxies have experienced recent star formation episodes that
are fully confined to their outer (R > 0.7R_90) regions. The fraction of stars
formed in a single episode is only 2 - 3 % of the underlying stellar mass, but
such bursts contribute nearly all the stellar mass formed in the last 2 Gyr.
Recent star formation in outer disks is strongly correlated with the global
atomic gas fraction of the galaxy, but not its global molecular gas fraction.
We suggest that outer episodic star formation is triggered by gas accretion
events.


title: Limits on Semiclassical Fluctuations in the Primordial Universe

abstract:
  We place limits on semiclassical fluctuations that might be present in the
primordial perturbation spectrum. These can arise if some signatures of
pre-inflationary features survive the expansion, or could be created by
whatever mechanism ends inflation. We study two possible models for such
remnant fluctuations, both of which break the isotropy of CMB on large scales.
We first consider a semiclassical fluctuation in one Fourier mode of primordial
perturbations. The second scenario we analyze is a semiclassical Gaussian bump
somewhere in space. These models are tested with the seven-year WMAP data using
a Markov Chain Monte Carlo Bayesian analysis, and we place limits on these
fluctuations. The upper bound for the amplitude of a fluctuation in a single
Fourier mode is a<=10^(-4), while for the Gaussian bump a<=10^(-3).


title:
GBT Detection of Polarization-dependent HI Absorption and HI Outflows in
  Local ULIRGs and Quasars

abstract:
  We present the results of a 21-cm HI survey of 27 local massive gas-rich
late-stage mergers and merger remnants with the Robert C. Byrd Green Bank
Telescope (GBT). These remnants were selected from the Quasar/ULIRG Evolution
Study (QUEST) sample of ultraluminous infrared galaxies (ULIRGs; L$_{8-1000 \mu
m} > 10^{12}$ L$_\odot$) and quasars; our targets are all bolometrically
dominated by active galactic nuclei (AGN) and sample the later phases of the
proposed ULIRG-to-quasar evolutionary sequence. We find the prevalence of HI
absorption (emission) to be 100% (29%) in ULIRGs with HI detections, 100% (88%)
in FIR-strong quasars, and 63% (100%) in FIR-weak quasars. The absorption
features are associated with powerful neutral outflows that change from being
mainly driven by star formation in ULIRGs to being driven by the AGN in the
quasars. These outflows have velocities that exceed 1500 km s$^{-1}$ in some
cases. Unexpectedly, we find polarization-dependent HI absorption in 57% of our
spectra (88% and 63% of the FIR-strong and FIR-weak quasars, respectively). We
attribute this result to absorption of polarized continuum emission from these
sources by foreground HI clouds. About 60% of the quasars displaying polarized
spectra are radio-loud, far higher than the $\sim$10% observed in the general
AGN population. This discrepancy suggests that radio jets play an important
role in shaping the environments in these galaxies. These systems may represent
a transition phase in the evolution of gas-rich mergers into "mature" radio
galaxies.


title: Spin Liquid Regimes at Nonzero Temperature in Quantum Spin Ice

abstract:
  Quantum spin liquids are highly entangled ground states of quantum systems
with emergent gauge structure, fractionalized spinon excitations, and other
unusual properties. While these features clearly distinguish quantum spin
liquids from conventional, mean-field-like states at zero temperature (T),
their status at T>0 is less clear. Strictly speaking, it is known that most
quantum spin liquids lose their identity at non-zero temperature, being in that
case adiabatically transformable into a trivial paramagnet. This is the case
for the U(1) quantum spin liquid states recently proposed to occur in the
quantum spin ice pyrochlores. Here we propose, however, that in practical
terms, the latter quantum spin liquids can be regarded as distinct phases from
the high temperature paramagnet. Through a combination of gauge mean field
theory calculations and physical reasoning, we argue that these systems sustain
both quantum spin liquid and thermal spin liquid phases, dominated by quantum
fluctuations and entropy, respectively. These phases are separated by a first
order "thermal confinement" transition, such that for temperatures below the
transition, spinons and emergent photons are coherently propagating
excitations, and above it the dynamics is classical. Even for parameters for
which the ground state is magnetically ordered and not a quantum spin liquid,
this strong first order transition occurs, pre-empting conventional Landau-type
criticality. We argue that this picture explains the anomalously low
temperature phase transition observed in the quantum spin ice material
Yb2Ti2O7.


title:
Giant radio relics in galaxy clusters: reacceleration of fossil
  relativistic electrons?

abstract:
  Many bright radio relics in the outskirts of galaxy clusters have low
inferred Mach numbers, defying expectations from shock acceleration theory and
heliospheric observations that the injection efficiency of relativistic
particles plummets at low Mach numbers. With a suite of cosmological
simulations, we follow the diffusive shock acceleration as well as radiative
and Coulomb cooling of cosmic ray electrons during the assembly of a cluster.
We find a substantial population of fossil electrons. When reaccelerated at a
shock (through diffusive shock acceleration), they are competitive with direct
injection at strong shocks and overwhelmingly dominate by many orders of
magnitude at weak shocks, Mach < 3, which are the vast majority at the cluster
periphery. Their relative importance depends on cooling physics and is robust
to the shock acceleration model used. While the abundance of fossils can vary
by a factor of ~10, the typical reaccelerated fossil population has radio
brightness in excellent agreement with observations. Fossil electrons with 1 <
gamma < 100 (10 < gamma < 10^4) provide the main seeds for reacceleration at
strong (weak) shocks; we show that these are well-resolved by our simulation.
We construct a simple self-similar analytic model which assumes steady recent
injection and cooling. It agrees well with our simulations, allowing rapid
estimates and physical insight into the shape of the distribution function. We
predict that LOFAR should find many more bright steep-spectrum radio relics,
which are inconsistent with direct injection. A failure to take fossil cosmic
ray electrons into account will lead to erroneous conclusions about the nature
of particle acceleration at weak shocks; they arise from well-understood
physical processes and cannot be ignored.


title: Three-loop calculations in non-Abelian gauge theories

abstract:
  A detailed description of the method for analytical evaluation of the
three-loop contributions to renormalization group functions is presented. This
method is employed to calculate the charge renormalization function and
anomalous dimensions for non-Abelian gauge theories with fermions in the
three-loop approximation. A three-loop expression for the effective charge of
QCD is given. Charge renormalization effects in the SU(4)-supersymmetric gauge
model is shown to vanish at this level. A complete list of required formulas is
given in Appendix.
  The above-mentioned results of three-loop calculations have been published by
the present authors (with A.Yu., Zharkov and L.V., Avdeev) in 1980 in Physics
Letters B. The present text, which treats the subject in more details and
contains a lot of calculational techniques, has also been published in 1980 as
the JINR Communication E2-80-483.


title: Mutual information area laws for thermal free fermions

abstract:
  We provide a rigorous and asymptotically exact expression of the mutual
information of translationally invariant free fermionic lattice systems in a
Gibbs state. In order to arrive at this result, we introduce a novel
frameworkfor computing determinants of Toeplitz operators with smooth symbols,
and for treating Toeplitz matrices with system size dependent entries. The
asymptotically exact mutual information for a partition of the one-dimensional
lattice satisfies an area law, with a prefactor which we compute explicitly. As
examples, we discuss the fermionic XX model in one dimension and free fermionic
models on the torus in higher dimensions in detail. Special emphasis is put
onto the discussion of the temperature dependence of the mutual information,
scaling like the logarithm of the inverse temperature, hence confirming an
expression suggested by conformal field theory. We also comment on the
applicability of the formalism to treat open systems driven by quantum noise.
In the appendix, we derive useful bounds to the mutual information in terms of
purities. Finally, we provide a detailed error analysis for finite system
sizes. This analysis is valuable in its own right for the abstract theory of
Toeplitz determinants.

categories: quant-ph cond-mat.stat-mech math-ph math.MP


title: Cosmological Constant, Near Brane Behavior and Singularities

abstract:
  We show that the classical cosmological constant in type II flux
compactifications can be written as a sum of terms from the action of localized
sources plus a specific contribution from non-trivial background fluxes.
Exploiting two global scaling symmetries of the classical supergravity action,
we find that the flux contribution can in many interesting cases be set to zero
such that the cosmological constant is fully determined by the boundary
conditions of the fields in the near-source region. This generalizes and makes
more explicit previous arguments in the literature. We then discuss the problem
of putting \bar{D3}-branes at the tip of the Klebanov-Strassler throat glued to
a compact space in type IIB string theory so as to engineer a de Sitter
solution. Our result for the cosmological constant and a simple global argument
indicate that inserting a fully localized and backreacting \bar{D3}-brane into
such a background yields a singular energy density for the NSNS and RR 3-form
field strengths at the \bar{D3}-brane. This argument does not rely on partial
smearing of the \bar{D3}-brane or a linearization of field equations, but on a
few general assumptions that we also discuss carefully.


title: Protostellar Disk Formation Enabled by Weak, Misaligned Magnetic Fields

abstract:
  The gas from which stars form is magnetized, and strong magnetic fields can
efficiently transport angular momentum. Most theoretical models of this
phenomenon find that it should prevent formation of large (>100 AU),
rotationally-supported disks around most protostars, even when non-ideal
magnetohydrodynamic (MHD) effects that allow the field and gas to decouple are
taken into account. Using recent observations of magnetic field strengths and
orientations in protostellar cores, we show that this conclusion is incorrect.
The distribution of magnetic field strengths is very broad, and alignments
between fields and angular momentum vectors within protostellar cores are
essentially random. By combining the field strength and misalignment data with
MHD simulations showing that disk formation is expected for both weak and
misaligned fields, we show that these observations imply that we should expect
disk fractions of ~10 - 50% even when protostars are still deeply embedded in
their parent cores, and even if the gas is governed by ideal MHD.


title: Progress with PXIE MEBT Chopper

abstract:
  A capability to provide a large variety of bunch patterns is crucial for the
concept of the Project X serving MW-range beam to several experiments
simultaneously. This capability will be realized by the Medium Energy Beam
Transport's (MEBT) chopping system that will divert 80% of all bunches of the
initially 5mA, 2.1 MeV CW 162.5 MHz beam to an absorber according to a
pre-programmed bunch-by-bunch selection. Being considered one of the most
challenging components, the chopping system will be tested at the Project X
Injector Experiment (PXIE) facility that will be built at Fermilab as a
prototype of the Project X front end. The bunch deflection will be made by two
identical sets of travelling-wave kickers working in sync. Currently, two
versions of the kickers are being investigated: a helical 200 Ohm structure
with a switching-type 500 V driver and a planar 50 Ohm structure with a linear
250 V amplifier. This paper will describe the chopping system scheme and
functional specifications for the kickers, present results of electromagnetic
measurements of the models, discuss possible driver schemes, and show a
conceptual mechanical design.


title:
Regularization and nonlinearities for neural language models: when are
  they needed?

abstract:
  Neural language models (LMs) based on recurrent neural networks (RNN) are
some of the most successful word and character-level LMs. Why do they work so
well, in particular better than linear neural LMs? Possible explanations are
that RNNs have an implicitly better regularization or that RNNs have a higher
capacity for storing patterns due to their nonlinearities or both. Here we
argue for the first explanation in the limit of little training data and the
second explanation for large amounts of text data. We show state-of-the-art
performance on the popular and small Penn dataset when RNN LMs are regularized
with random dropout. Nonetheless, we show even better performance from a
simplified, much less expressive linear RNN model without off-diagonal entries
in the recurrent matrix. We call this model an impulse-response LM (IRLM).
Using random dropout, column normalization and annealed learning rates, IRLMs
develop neurons that keep a memory of up to 50 words in the past and achieve a
perplexity of 102.5 on the Penn dataset. On two large datasets however, the
same regularization methods are unsuccessful for both models and the RNN's
expressivity allows it to overtake the IRLM by 10 and 20 percent perplexity,
respectively. Despite the perplexity gap, IRLMs still outperform RNNs on the
Microsoft Research Sentence Completion (MRSC) task. We develop a slightly
modified IRLM that separates long-context units (LCUs) from short-context units
and show that the LCUs alone achieve a state-of-the-art performance on the MRSC
task of 60.8%. Our analysis indicates that a fruitful direction of research for
neural LMs lies in developing more accessible internal representations, and
suggests an optimization regime of very high momentum terms for effectively
training such models.


title: Chromospheric activity as age indicator

abstract:
  Chromospheric activity has been calibrated and widely used as an age
indicator. However, it has been suggested that the viability of this age
indicator is, in the best case, limited to stars younger than about 1.5 Gyr. I
aim to define the age range for which chromospheric activity is a robust
astrophysical clock. I collected literature measurements of the S-index in
field stars, which is a measure of the strength of the H and K lines of the Ca
II and a proxy for chromospheric activity, and exploited the homogeneous
database of temperature and age determinations for field stars provided by the
Geneva-Copenhagen survey of the solar neighbourhood. Field data, inclusive data
previously used to calibrate chromospheric ages, confirm the result found using
open cluster data, i.e. there is no decay of chromospheric activity after about
2 Gyr. The only existing indication supporting the viability of chromospheric
ages older than 2 Gyr is the similarity of chromospheric activity levels in the
components of 35 dwarf binaries. However, even in the most optimistic scenario,
uncertainty in age determination for field stars and lack of sufficient data in
open clusters make any attempt of calibrating an age activity relationship for
old stars premature. The hypothesis that chromospheric activity follows the
Skumanich law, i.e. that it is proportional to the inverse square root of the
age, should be relaxed.


title:
Analytical results from the quantum theory of a single-emitter
  nanolaser. II

abstract:
  Using two equivalent approaches, Heisenberg-Langevin and density operator, we
investigate the properties of nanolaser: an incoherently pumped single
two-level system interacting with a single-cavity mode of finite finesse. We
show that in the case of good-cavity regime the Heisenberg-Langevin approach
provides the analytical results for linewidth, amplitude fluctuation spectrum,
and intracavity Mandel Q-parameter. In the bad-cavity regime we estimate the
frequency at which the peak of relaxation oscillations appears. With the help
of the master equation for density operator written in terms of coherent states
we obtain approximated expression for Glauber-Sudarshan P function. This
solution can be used in the case of good-cavity regime and allows us to
investigate in more detail the thresholdless behaviour of the nanolaser. All
two approaches are in a very good agreement with each other and numerical
simulations.


title:
A High-power 650 MHz CW Magnetron Transmitter for Intensity Frontier
  Superconducting Accelerators

abstract:
  A concept of a 650 MHz CW magnetron transmitter with fast control in phase
and power, based on two-stage injection-locked CW magnetrons, has been proposed
to drive Superconducting Cavities (SC) for intensity-frontier accelerators. The
concept is based on a theoretical model considering a magnetron as a forced
oscillator and experimentally verified with a 2.5 MW pulsed magnetron. To
fulfill fast control of phase and output power requirements of SC accelerators,
both two-stage injection-locked CW magnetrons are combined with a 3-dB hybrid.
Fast control in output power is achieved by varying the input phase of one of
the magnetrons. For output power up to 250 kW we expect the output/input power
ratio to be about 35 to 40 dB in CW or quasi-CW mode with long pulse duration.
All magnetrons of the transmitter should be based on commercially available
models to decrease the cost of the system. An experimental model using 1 kW,
CW, S-band, injection-locked magnetrons with a 3-dB hybrid combiner has been
developed and built for study. A description of the model, simulations, and
experimental results are presented and discussed in this work.


title: On the classification of G-graded twisted algebras

abstract:
  Let G denote a group and let W be an algebra over a commutative ring R. We
will say that W is a G-graded twisted algebra (not necessarily commutative,
neither associative) if there exists a G-grading W=\bigoplus_{g \in G}W_{g}
where each summand W_{g} is a free rank one R -module, and W has no monomial
zero divisors (for each pair of nonzero elements w_{a},w_{b} en W_{a} and W_{b}
their product is not zero, w_{a}w_{b}\neq 0). It is also assumed that W has an
identity element. In this article, methods of group cohomology are used to
study the general problem of classification under graded isomorphisms. We give
a full description of these algebras in the associative cases, for complex and
real algebras. In the nonassociative case, an analogous result is obtained
under a symmetry condition of the corresponding associative function of the
algebra, and when the group providing the grading is finite cyclic.


title:
Achievable rate region based on coset codes for multiple access channel
  with states

abstract:
  We prove that the ensemble the nested coset codes built on finite fields
achieves the capacity of arbitrary discrete memoryless point-to-point channels.
Exploiting it's algebraic structure, we develop a coding technique for
communication over general discrete multiple access channel with channel state
information distributed at the transmitters. We build an algebraic coding
framework for this problem using the ensemble of Abelian group codes and
thereby derive a new achievable rate region. We identify non-additive and
non-symmteric examples for which the proposed achievable rate region is
strictly larger than the one achievable using random unstructured codes.


title:
Designing antibiotic cycling strategies by determining and understanding
  local adaptive landscapes

abstract:
  The evolution of antibiotic resistance among bacteria threatens our continued
ability to treat infectious diseases. The need for sustainable strategies to
cure bacterial infections has never been greater. So far, all attempts to
restore susceptibility after resistance has arisen have been unsuccessful,
including restrictions on prescribing [1] and antibiotic cycling [2,3]. Part of
the problem may be that those efforts have implemented different classes of
unrelated antibiotics, and relied on removal of resistance by random loss of
resistance genes from bacterial populations (drift). Here, we show that
alternating structurally similar antibiotics can restore susceptibility to
antibiotics after resistance has evolved. We found that the resistance
phenotypes conferred by variant alleles of the resistance gene encoding the TEM
{\beta}-lactamase (blaTEM) varied greatly among 15 different {\beta}-lactam
antibiotics. We captured those differences by characterizing complete adaptive
landscapes for the resistance alleles blaTEM-50 and blaTEM-85, each of which
differs from its ancestor blaTEM-1 by four mutations. We identified pathways
through those landscapes where selection for increased resistance moved in a
repeating cycle among a limited set of alleles as antibiotics were alternated.
Our results showed that susceptibility to antibiotics can be sustainably
renewed by cycling structurally similar antibiotics. We anticipate that these
results may provide a conceptual framework for managing antibiotic resistance.
This approach may also guide sustainable cycling of the drugs used to treat
malaria and HIV.


title: High Gradient Tests of the Fermilab SSR1 Cavity

abstract:
  In Fermilab we are build and tested several superconducting Single Spoke
Resonators (SSR1, \beta=0.22) which can be used for acceleration of low beta
ions. Fist two cavities performed very well during cold test in Vertical Test
Station at FNAL. One dressed cavity was also tested successfully in Horizontal
Test Station. Currently we are building 8 cavity cryomodule for PIXIE project.
Additional 10 cavities were manufactured in the industry and on-going cold test
results will be presented in this poster.


title:
A convergence on Boolean algebras generalizing the convergence on the
  Aleksandrov cube

abstract:
  We compare the forcing related properties of a complete Boolean algebra B
with the properties of the convergences $\lambda_s$ (the algebraic convergence)
and $\lambda_{ls}$ on B generalizing the convergence on the Cantor and
Aleksandrov cube respectively. In particular we show that $\lambda_{ls}$ is a
topological convergence iff forcing by B does not produce new reals and that
$\lambda_{ls}$ is weakly topological if B satisfies condition $(\hbar)$
(implied by the ${\mathfrak t}$-cc). On the other hand, if $\lambda_{ls}$ is a
weakly topological convergence, then B is a $2^{\mathfrak h}$-cc algebra or in
some generic extension the distributivity number of the ground model is greater
than or equal to the tower number of the extension. So, the statement "The
convergence $\lambda_{ls}$ on the collapsing algebra $B=\ro
((\omega_2)^{<\omega})$ is weakly topological" is independent of ZFC.


title: A note on the coincidence of the projective and conformal Weyl tensors

abstract:
  This article examines the coincidence of the projective and conformal Weyl
tensors associated to a given connection D. The connection may be a general
Weyl connection associated to a conformal class of metrics [g]. The main result
for n>3 is that the Weyl tensors coincide iff D is the Levi-Civita connection
of an Einstein metric.


title: New symmetry in the Rabi model

abstract:
  It is recognised that, apart from the total energy conservation, there is a
nonlocal $\mathbb{Z}_2$ and a somewhat hidden symmetry in this model.
Conditions for the existence of this observable, its form, and its explicit
construction are presented.


title: Initial states of qubit-boson models leading to conserved quantities

abstract:
  It is possible to prepare a composite qubit-environment system so that its
time evolution will guarantee the conservation of a preselected qubit's
observable. In general, this observable is not associated with a symmetry. The
latter may not even be present in the subsystem. The initial states which lead
to such a quantity conserved dynamics form a subspace of the qubit-environment
space of states. General construction of this subspace is presented and
illustrated by two examples. The first one is the exactly soluble
Jaynes-Cummings model and the second is the multi-photon Rabi model.


title: Anisotropic chiral d+id superconductivity in NaxCoO2 yH2O

abstract:
  Since its discovery, the superconducting phase in water-intercalated sodium
cobaltates NaxCoO2 yH2O (x~0.3, y~1.3) has posed fundamental challenges in
terms of experimental investigation and theoretical understanding. By a
combined dynamical mean-field and renormalization group approach, we find an
anisotropic chiral d+id wave state as a consequence of multi-orbital effects,
Fermi surface topology, and magnetic fluctuations. It naturally explains the
singlet property and close-to-nodal gap features of the superconducting phase
as indicated by experiments.


title: The distribution of the variance of primes in arithmetic progressions

abstract:
  Hooley conjectured that the variance V(x;q) of the distribution of primes up
to x in the arithmetic progressions modulo q is asymptotically x log q, in some
unspecified range of q\leq x. On average over 1\leq q \leq Q, this conjecture
is known unconditionally in the range x/(log x)^A \leq Q \leq x; this last
range can be improved to x^{\frac 12+\epsilon} \leq Q \leq x under the
Generalized Riemann Hypothesis (GRH). We argue that Hooley's conjecture should
hold down to (loglog x)^{1+o(1)} \leq q \leq x for all values of q, and that
this range is best possible. We show under GRH and a linear independence
hypothesis on the zeros of Dirichlet L-functions that for moderate values of q,
\phi(q)e^{-y}V(e^y;q) has the same distribution as that of a certain random
variable of mean asymptotically \phi(q) log q and of variance asymptotically
2\phi(q)(log q)^2. Our estimates on the large deviations of this random
variable allow us to predict the range of validity of Hooley's Conjecture.


title: Chern-Simons-Matter Theory

abstract:
  In this paper we will deform a ABJ theory in $\mathcal{N}= 3$ harmonic
superspace without breaking any supersymmetry. We will analyse this ABJ theory
and show that it retains the full $\mathcal{N}= 6$ supersymmetry. We will then
analyse the gauge fixing and ghost terms for this model in various gauges. We
will also analyse the corresponding BRST and anti-BRST symmetries of this
model.


title:
Water transport in protoplanetary disks and the hydrogen isotopic
  composition of chondrites

abstract:
  The D/H ratios of carbonaceous chondrites, believed to reflect that of water
in the inner early solar system, are intermediate between the protosolar value
and that of most comets. The isotopic composition of cometary water has been
accounted for by several models where the isotopic composition of water vapor
evolved by isotopic exchange with hydrogen gas in the protoplanetary disk.
However, the position and the wide variations of the distribution of D/H ratios
in carbonaceous chondrites have yet to be explained. In this paper, we assume
that the D/H composition of cometary ice was achieved in the disk building
phase and model the further isotopic evolution of water in the inner disk in
the classical T Tauri stage. Reaction kinetics compel isotopic exchange between
water and hydrogen gas to stop at $\sim$500 K, but equilibrated water can be
transported to the snow line (and beyond) via turbulent diffusion and
consequently mix with isotopically comet-like water. Under certain simplifying
assumptions, we calculate analytically this mixing and the resulting
probability distribution function of the D/H ratio of ice accreted in
planetesimals and compare it with observational data. The distribution
essentially depends on two parameters: the radial Schmidt number Sc$_R$, which
ratios the efficiencies of angular momentum transport and turbulent diffusion,
and the range of heliocentric distances of accretion sampled by chondrites. The
minimum D/H ratio of the distribution corresponds to the composition of water
condensed at the snow line, which is primarily set by Sc$_R$. Observations
constrain the latter to low values (0.1-0.3), which suggests that turbulence in
the planet-forming region was hydrodynamical in nature, as would be expected in
a dead zone. Such efficient outward diffusion would also account for the
presence of high-temperature minerals in comets.


title: Characterizations of the Quaternionic Mannheim Curves in E^4

abstract:
  In [5], Matsuda and Yorozo obtained that Mannheim curves in 4-dimensional
Euclidean space. In this study, we define quaternionic Mannheim curves and we
give some characterizations of them in Euclidean 3-space and 4-space.


title: Nilpotent commuting varieties of the Witt algebra

abstract:
  Let $\mathfrak{g}$ be the $p$-dimensional Witt algebra over an algebraically
closed field $k$ of characteristic $p>3$. Let $\mathscr{N}={x\in\ggg\mid
x^{[p]}=0}$ be the nilpotent variety of $\mathfrak{g}$, and
$\mathscr{C}(\mathscr{N}):=\{(x,y)\in \mathscr{N}\times\mathscr{N}\mid
[x,y]=0\}$ the nilpotent commuting variety of $\mathfrak{g}$. As an analogue of
Premet's result in the case of classical Lie algebras [A. Premet, Nilpotent
commuting varieties of reductive Lie algebras. Invent. Math., 154, 653-683,
2003.], we show that the variety $\mathscr{C}(\mathscr{N})$ is reducible and
equidimensional. Irreducible components of $\mathscr{C}(\mathscr{N})$ and their
dimension are precisely given. Furthermore, the nilpotent commuting varieties
of Borel subalgebras are also determined.


title: Direct CP violation in charmless B decays at BaBar

abstract:
  We present direct CP violation measurements using the full BaBar dataset of
471 million BBbar pairs for the following charmless B decays: B0-->rho0Kstar0,
B0-->f0Kstar0, B0-->rho-Kstar+ and for the Dalitz plots of B+-->K+K-K+,
B+-->KsKsK+ and B0-->KsK+K-.


title:
QED effective action for an O(2)xO(3) symmetric field in the full mass
  range

abstract:
  An interesting class of background field configurations in QED are the
O(2)xO(3) symmetric fields. Those backgrounds have some instanton-like
properties and yield a one-loop effective action that is highly nontrivial but
amenable to numerical calculation, for both scalar and spinor QED. Here we use
the recently developed "partial-wave-cutoff method" for a numerical analysis of
both effective actions in the full mass range. In particular, at large mass we
are able to match the asymptotic behavior of the physically renormalized
effective action against the leading two mass levels of the inverse mass (or
heat kernel) expansion. At small mass we obtain good numerical results even in
the massless case for the appropriately (unphysically) renormalized effective
action after the removal of the chiral anomaly term through a small radial
cutoff factor. In particular, we show that the effective action after this
removal remains finite in the massless limit, which also provides indirect
support for M. Fry's hypothesis that the QED effective action in this limit is
dominated by the chiral anomaly term.