title: Classical limits of quantum toroidal and affine Yangian algebras

abstract:
  In this short note, we compute the classical limits of the quantum toroidal
and the affine Yangian algebras of sl(n) by generalizing our arguments for
gl(1) from arXiv:1404.5240. These results were mentioned as motivation in the
recent study of toroidal algebras by [Feigin-Jimbo-Miwa-Mukhin], while they
played a crucial role in the recent paper arXiv:1512.09109 of the author and
Bershtein. An alternative proof of our key isomorphisms for n>2 was first
established by [Varagnolo-Vasserot]. We also discuss some consequences of these
results.


title: From fire whirls to blue whirls and combustion without pollution

abstract:
  Fire whirls are powerful, spinning disasters for people and surroundings when
they occur in large urban and wildland fires. While fire whirls have long been
studied for fire safety applications, previous research has yet to harness
their potential burning efficiency for enhanced combustion. This paper presents
laboratory studies of fire whirls initiated as pool fires, but where the fuel
sits on a water surface, seeding an idea of exploiting the high-efficiency of
fire whirls for oil-spill remediation. We show the transition from a pool fire,
to a fire whirl, and then to a previously unobserved state, a blue whirl. A
blue whirl is smaller, very stable, and burns completely blue-violet in a
hydrocarbon flame, indicating soot-free burning. The combination of fast mixing
and the water-surface boundary creates the conditions leading to nearly
soot-free combustion. With the worldwide need to reduce emissions from both
wanted and unwanted combustion, discovery of this new state points to new
pathways for highly efficient and low-emission energy production and fuel-spill
cleanup. Because current methods to generate a stable vortex are difficult, we
also propose that the blue whirl may serve as a research platform for
fundamental studies of vortices in fluid mechanics.


title: Waiting for Unruh

abstract:
  How long does a uniformly accelerated observer need to interact with a
quantum field in order to record thermality in the Unruh temperature? We
address this question for a pointlike Unruh-DeWitt detector, coupled linearly
to a real Klein-Gordon field of mass $m\ge0$ and treated within first order
perturbation theory, in the limit of large detector energy gap
$E_{\text{gap}}$. We first show that when the interaction duration $\Delta T$
is fixed, thermality in the sense of detailed balance cannot hold as
$E_{\text{gap}}\to\infty$, and this property generalises from the Unruh effect
to any Kubo-Martin-Schwinger state satisfying certain technical conditions. We
then specialise to a massless field in four spacetime dimensions and show that
detailed balance does hold when $\Delta T$ grows as a power-law in
$E_{\text{gap}}$ as $E_{\text{gap}}\to\infty$, provided the switch-on and
switch-off intervals are stretched proportionally to $\Delta T$ and the
switching function has sufficiently strong Fourier decay. By contrast, if
$\Delta T$ grows by stretching a plateau in which the interaction remains at
constant strength but keeping the duration of the switch-on and switch-off
intervals fixed, detailed balance at $E_{\text{gap}}\to\infty$ requires $\Delta
T$ to grow faster than any polynomial in $E_{\text{gap}}$, under mild technical
conditions. These results also hold for a static detector in a Minkowski heat
bath.
  The results limit the utility of the large $E_{\text{gap}}$ regime as a probe
of thermality in time-dependent versions of the Hawking and Unruh effects, such
as an observer falling into a radiating black hole. They may also have
implications on the design of prospective experimental tests of the Unruh
effect.


title:
Endohedral confinement of a DNA dodecamer onto pristine carbon nanotubes
  and the stability of the canonical B form

abstract:
  Although carbon nanotubes are potential candidates for DNA encapsulation and
subsequent delivery of biological payloads to living cells, the thermodynamical
spontaneity of DNA encapsulation under physiological conditions is still a
matter of debate. Using enhanced sampling techniques, we show for the first
time that, given a sufficiently large carbon nanotube, the confinement of a
double-stranded DNA segment, 5'-D(*CP*GP*CP*GP*AP*AP*TP*TP*CP*GP*CP*G)-3', is
thermodynamically favourable under physiological environments (134 mM, 310 K, 1
bar), leading to DNA-nanotube hybrids with lower free energy than the
unconfined biomolecule. A diameter threshold of 3 nm is established below which
encapsulation is inhibited. The confined DNA segment maintains its
translational mobility and exhibits the main geometrical features of the
canonical B form. To accommodate itself within the nanopore, the DNA end-to-end
length increases from 3.85 nm up to approximately 4.1 nm, due to a 0.3 nm
elastic expansion of the strand termini. The canonical Watson-Crick H-bond
network is essentially conserved throughout encapsulation, showing that the
contact between the DNA segment and the hydrophobic carbon walls results in
minor rearrangements of the nucleotides H-bonding. The results obtained here
are paramount to the usage of carbon nanotubes as encapsulation media for next
generation drug delivery technologies.

categories: physics.bio-ph cond-mat.mes-hall physics.chem-ph q-bio.BM


title: Secondary cosmic ray nuclei in the light of the Single Source Model

abstract:
  Evidence for a local 'Single Source' of cosmic rays is amassing by way of the
recent precise measurements of various cosmic ray energy spectra from the
AMS-02 instrument. To observations of individual cosmic ray nuclei, electrons,
positrons and antiprotons must now be added the determination of the
boron-to-carbon ratio and the energy spectrum of lithium to 2000 GV with high
precision. Our analysis leads us to claim that, with certain assumptions about
the propagation in the Galaxy, the results confirm our arguments regarding the
presence of a local single source, perhaps, a supernova remnant (SNR). An
attempt is made to determine some of the properties of this SNR and its
progenitor star.


title: $(2/2/3)$-SAT problem and its applications in dominating set problems

abstract:
  The satisfiability problem is known to be $\mathbf{NP}$-complete in general
and for many restricted cases. One way to restrict instances of $k$-SAT is to
limit the number of times a variable can be occurred. It was shown that for an
instance of 4-SAT with the property that every variable appears in exactly 4
clauses (2 times negated and 2 times not negated), determining whether there is
an assignment for variables such that every clause contains exactly two true
variables and two false variables is $\mathbf{NP}$-complete. In this work, we
show that deciding the satisfiability of 3-SAT with the property that every
variable appears in exactly four clauses (two times negated and two times not
negated), and each clause contains at least two distinct variables is $
\mathbf{NP} $-complete. We call this problem $(2/2/3)$-SAT. For an $r$-regular
graph $G = (V,E)$ with $r\geq 3$, it was asked in [Discrete Appl. Math.,
160(15):2142--2146, 2012] to determine whether for a given independent set $T $
there is an independent dominating set $D$ that dominates $T$ such that $ T
\cap D =\varnothing $? As an application of $(2/2/3)$-SAT problem we show that
for every $r\geq 3$, this problem is $ \mathbf{NP} $-complete. Among other
results, we study the relationship between 1-perfect codes and the incidence
coloring of graphs and as another application of our complexity results, we
prove that for a given cubic graph $G$ deciding whether $G$ is 4-incidence
colorable is $ \mathbf{NP} $-complete.


title: Minimal Asymmetric Graphs

abstract:
  Confirming a conjecture of Ne\v{s}et\v{r}il, we show that up to isomorphism
there is only a finite number of finite minimal asymmetric undirected graphs.
In fact, there are exactly 18 such graphs. We also show that these graphs are
exactly the finite minimal involution-free graphs.


title: Parker's model in geodynamo

abstract:
  We consider how information on geostrophic flows in the planetary cores,
taken from 3D simulations in the sphere, can be used in 2D Parker's geodynamo
model with the simple forms of the $\alpha$-quenching. Using cluster computer
systems dependence of dynamo equations solution on the magnitudes of $\alpha$-
and $\omega$-effects is studied. We show that geostrophical flow can produce
the well-known Z-structure of the poloidal magnetic field without the feed-back
of the magnetic field onto the large-scale velocity field. The influence of
fluctuations of $\alpha$-effect on magnetic field generation, its spectral
properties, in respect to the geodynamo applications, is also discussed.


title: Simplicial Lusternik-Schnirelmann category

abstract:
  The simplicial LS-category of a finite abstract simplicial complex is a new
invariant of the strong homotopy type, defined in purely combinatorial terms,
that generalizes to arbitrary simplicial complexes the well known notion of
arboricity of a graph, and that allows to develop all the machinery of
algebraic topology which is costumary in the classical theory of
Lusternik-Schnirelmann category.


title:
Some properties of non-linear fractional stochastic heat equations on
  bounded domains

abstract:
  Consider the following stochastic partial differential equation,
\begin{equation*} \partial_t u_t(x)=
  \mathcal{L}u_t(x)+ \xi\sigma (u_t(x)) \dot F(t,x), \end{equation*} where
$\xi$ is a positive parameter and $\sigma$ is a globally Lipschitz continuous
function. The stochastic forcing term $\dot F(t,x)$ is white in time but
possibly colored in space. The operator $\mathcal{L}$ is a non-local operator.
We study the behaviour of the solution with respect to the parameter $\xi$,
extending the results in \cite{FoonNual} and \cite{Bin}


title: A periodic model for the dynamics of cell volume

abstract:
  We prove the existence and uniqueness of positive periodic solution for a
model describing the dynamics of cell volume flux, introduced in Julio A.
Hernandez \cite{H}. We also show that the periodic solution is a global
attractor. Our results confirm the conjectures made in an interesting recent
book of P.J. Torres \cite{T}.


title: Survival of habitable planets in unstable planetary systems

abstract:
  Many observed giant planets lie on eccentric orbits. Such orbits could be the
result of strong scatterings with other giant planets. The same dynamical
instability that produces these scatterings may also cause habitable planets in
interior orbits to become ejected, destroyed, or be transported out of the
habitable zone. We say that a habitable planet has resilient habitability if it
is able to avoid ejections and collisions and its orbit remains inside the
habitable zone. Here we model the orbital evolution of rocky planets in
planetary systems where giant planets become dynamically unstable. We measure
the resilience of habitable planets as a function of the observed, present-day
masses and orbits of the giant planets. We find that the survival rate of
habitable planets depends strongly on the giant planet architecture. Equal-mass
planetary systems are far more destructive than systems with giant planets of
unequal masses. We also establish a link with observation; we find that giant
planets with present-day eccentricities higher than 0.4 almost never have a
habitable interior planet. For a giant planet with an present-day eccentricity
of 0.2 and semimajor axis of 5 AU orbiting a Sun-like star, 50% of the orbits
in the habitable zone are resilient to the instability. As semimajor axis
increases and eccentricity decreases, a higher fraction of habitable planets
survive and remain habitable. However, if the habitable planet has rocky
siblings, there is a significant risk of rocky planet collisions that would
sterilize the planet.


title: Compression and the origins of Zipf's law for word frequencies

abstract:
  Here we sketch a new derivation of Zipf's law for word frequencies based on
optimal coding. The structure of the derivation is reminiscent of Mandelbrot's
random typing model but it has multiple advantages over random typing: (1) it
starts from realistic cognitive pressures (2) it does not require fine tuning
of parameters and (3) it sheds light on the origins of other statistical laws
of language and thus can lead to a compact theory of linguistic laws. Our
findings suggest that the recurrence of Zipf's law in human languages could
originate from pressure for easy and fast communication.

categories: cs.CL physics.data-an physics.soc-ph q-bio.NC


title: No-arbitrage and hedging with liquid American options

abstract:
  Since most of the traded options on individual stocks is of American type it
is of interest to generalize the results obtained in semi-static trading to the
case when one is allowed to statically trade American options. However, this
problem has proved to be elusive so far because of the asymmetric nature of the
positions of holding versus shorting such options. Here we provide a unified
framework and generalize the fundamental theorem of asset pricing (FTAP) and
hedging dualities in arXiv:1502.06681 (to appear in Annals of Applied
Probability) to the case where the investor can also short American options.
Following arXiv:1502.06681, we assume that the longed American options are
divisible. As for the shorted American options, we show that the divisibility
plays no role regarding arbitrage property and hedging prices. Then using the
method of enlarging probability spaces proposed in arXiv:1604.05517, we convert
the shorted American options to European options, and establish the FTAP and
sub- and super-hedging dualities in the enlarged space both with and without
model uncertainty.


title:
Optimized Binomial Quantum States of Complex Oscillators with Real
  Spectrum

abstract:
  Classical and nonclassical states of quantum complex oscillators with real
spectrum are presented. Such states are bi-orthonormal superpositions of $n+1$
energy eigenvectors of the system with binomial-like coefficients. For large
values of $n$ these optimized binomial states behave as photon added coherent
states when the imaginary part of the potential is cancelled.


title: Single Channel Speech Enhancement Using Outlier Detection

abstract:
  Distortion of the underlying speech is a common problem for single-channel
speech enhancement algorithms, and hinders such methods from being used more
extensively. A dictionary based speech enhancement method that emphasizes
preserving the underlying speech is proposed. Spectral patches of clean speech
are sampled and clustered to train a dictionary. Given a noisy speech spectral
patch, the best matching dictionary entry is selected and used to estimate the
noise power at each time-frequency bin. The noise estimation step is formulated
as an outlier detection problem, where the noise at each bin is assumed present
only if it is an outlier to the corresponding bin of the best matching
dictionary entry. This framework assigns higher priority in removing spectral
elements that strongly deviate from a typical spoken unit stored in the trained
dictionary. Even without the aid of a separate noise model, this method can
achieve significant noise reduction for various non-stationary noises, while
effectively preserving the underlying speech in more challenging noisy
environments.


title: On the capacity of the binary adversarial wiretap channel

abstract:
  New bounds on the semantic secrecy capacity of the binary adversarial wiretap
channel are established . Against an adversary which reads a $\rho_r$ fraction
of the transmitted codeword and modifies a $\rho_w$ fraction of the codeword,
we show an achievable rate of $1-h(\rho_w)-\rho_r$, where $h(\cdot)$ is the
binary entropy function. We also give an upper bound which is nearly matching
when $\rho_r$ is small.


title:
Linear Network Coding Capacity Region of The Smart Repeater with
  Broadcast Erasure Channels

abstract:
  This work considers the smart repeater network where a single source $s$
wants to send two independent packet streams to destinations $\{d_1,d_2\}$ with
the help of relay $r$. The transmission from $s$ or $r$ is modeled by packet
erasure channels: For each time slot, a packet transmitted by $s$ may be
received, with some probabilities, by a random subset of $\{d_1,d_2,r\}$; and
those transmitted by $r$ will be received by a random subset of $\{d_1,d_2\}$.
Interference is avoided by allowing at most one of $\{s,r\}$ to transmit in
each time slot. One example of this model is any cellular network that supports
two cell-edge users when a relay in the middle uses the same downlink resources
for throughput/safety enhancement.
  In this setting, we study the capacity region of $(R_1,R_2)$ when allowing
linear network coding (LNC). The proposed LNC inner bound introduces more
advanced packing-mixing operations other than the previously well-known
butterfly-style XOR operation on overheard packets of two co-existing flows. A
new LNC outer bound is derived by exploring the inherent algebraic structure of
the LNC problem. Numerical results show that, with more than 85% of the
experiments, the relative sum-rate gap between the proposed outer and inner
bounds is smaller than 0.08% under the strong-relaying setting and 0.04% under
arbitrary distributions, thus effectively bracketing the LNC capacity of the
smart repeater problem.


title: Algebraic and Nori fundamental gerbes

abstract:
  In this paper we extend the generalized algebraic fundamental group
constructed by Esnault and Hogadi to general fibered categories using the
language of gerbes. As an application we obtain a Tannakian interpretation for
the Nori fundamental gerbe defined by Borne and Vistoli for non smooth non
pseudo-proper algebraic stacks.


title: Minimax Estimation of the Volume of a Set with Smooth Boundary

abstract:
  We consider the problem of estimating the volume of a compact domain in a
Euclidean space based on a uniform sample from the domain. We assume the domain
has a boundary with positive reach. We propose a data splitting approach to
correct the bias of the plug-in estimator based on the sample alpha-convex
hull. We show that this simple estimator achieves a minimax lower bound that we
derive. Some numerical experiments corroborate our theoretical findings.


title:
Imprints of Electron-positron Winds on the Multi-wavelength Afterglows
  of Gamma-ray Bursts

abstract:
  Optical re-brightenings in the afterglows of some gamma-ray bursts (GRBs) are
unexpected within the framework of the simple external shock model. While it
has been suggested that the central engines of some GRBs are newly born
magnetars, we aim to relate the behaviors of magnetars to the optical
re-brightenings. A newly born magnetar will lose its rotational energy in the
form of Poynting-flux, which may be converted into a wind of electron-positron
pairs through some magnetic dissipation processes. As proposed by Dai (2004),
this wind will catch up with the GRB outflow and a long-lasting reverse shock
would form. By applying this scenario to GRB afterglows, we find that the
reverse shock propagating back into the electron-positron wind can lead to an
observable optical re-brightening and a simultaneous X-ray plateau (or X-ray
shallow decay). In our study, we select four GRBs, i.e., GRB 080413B, GRB
090426, GRB 091029, and GRB 100814A, of which the optical afterglows are well
observed and show clear re-brightenings. We find that they can be well
interpreted. In our scenario, the spin-down timescale of the magnetar should be
slightly smaller than the peak time of the re-brightening, which can provide a
clue to the characteristics of the magnetar.


title: Learning from the memory of Atari 2600

abstract:
  We train a number of neural networks to play games Bowling, Breakout and
Seaquest using information stored in the memory of a video game console Atari
2600. We consider four models of neural networks which differ in size and
architecture: two networks which use only information contained in the RAM and
two mixed networks which use both information in the RAM and information from
the screen. As the benchmark we used the convolutional model proposed in NIPS
and received comparable results in all considered games. Quite surprisingly, in
the case of Seaquest we were able to train RAM-only agents which behave better
than the benchmark screen-only agent. Mixing screen and RAM did not lead to an
improved performance comparing to screen-only and RAM-only agents.


title: MV-algebras and measure: some examples

abstract:
  We propose in this article a definition of a MV-algebra structure on a class
of subsets of some probability spaces and we work-out some examples. Our
intention is to convey, by mean of the simplest possible examples, the idea
that the topology of the geometric object under consideration might be
reflected in the MV-algebraic structure. We also discuss an example of Chang
and discuss similarities and differences with the proposed class of examples.


title: Magnetic moments of the hidden-charm pentaquark states

abstract:
  The magnetic moment of a baryon state is an equally important dynamical
observable as its mass, which encodes crucial information of its underlying
structure. According to the different color-flavor structure, we have
calculated the magnetic moments of the hidden-charm pentaquark states with
$J^P={\frac{1}{2}}^{\pm}$, ${\frac{3}{2}}^{\pm}$, ${\frac{5}{2}}^{\pm}$ and
${\frac{7}{2}}^{+}$ in the molecular model, the diquark-triquark model and the
diquark-diquark-antiquark model respectively. Although a good description for
the pentaquark mass spectrum and decay patterns has been obtained in all the
three models, different color-flavor structures lead to different magnetic
moments, which can be used to pin down their inner structures and distinguish
various models.


title: Parton Shower Uncertainties with Herwig 7: Benchmarks at Leading Order

abstract:
  We perform a detailed study of the sources of perturbative uncertainty in
parton shower predictions within the Herwig 7 event generator. We benchmark two
rather different parton shower algorithms, based on angular-ordered and
dipole-type evolution, against each other. We deliberately choose leading order
plus parton shower as the benchmark setting to identify a controllable set of
uncertainties. This will enable us to reliably assess improvements by
higher-order contributions in a follow-up work.


title:
Orbital motions of astronomical bodies and their Centre of Mass from
  different reference frames: a conceptual step between the Geocentric and
  Heliocentric models

abstract:
  The motion of astronomical bodies and the centre of mass of the system is not
always well perceived by students. One of the struggles is the conceptual
change of reference frame, which is the same that held back the acceptance of
the Heliocentric model over the Geocentric one. To address the question, the
notion of centre of mass, motion equations (and their numerical solution for a
system of multiple bodies), and change of referential is introduced. The
discussion is done based on conceptual and real world examples, using the solar
system. Consequently, through the use of simple "do it yourself" methods and
basic equations, students can debate complex motions, and have a wider and
potentially effective understanding of physics.


title: Sample Out-Of-Sample Inference Based on Wasserstein Distance

abstract:
  We present a novel inference approach that we call Sample Out-of-Sample (or
SOS) inference. The approach can be used widely, ranging from semi-supervised
learning to stress testing, and it is fundamental in the application of
data-driven Distributionally Robust Optimization (DRO). Our method enables
measuring the impact of plausible out-of-sample scenarios in a given
performance measure of interest, such as a financial loss. The methodology is
inspired by Empirical Likelihood (EL), but we optimize the empirical
Wasserstein distance (instead of the empirical likelihood) induced by
observations. From a methodological standpoint, our analysis of the asymptotic
behavior of the induced Wasserstein-distance profile function shows dramatic
qualitative differences relative to EL. For instance, in contrast to EL, which
typically yields chi-squared weak convergence limits, our asymptotic
distributions are often not chi-squared. Also, the rates of convergence that we
obtain have some dependence on the dimension in a non-trivial way but remain
controlled as the dimension increases.


title:
eLISA eccentricity measurements as tracers of binary black hole
  formation

abstract:
  Up to hundreds of black hole binaries individually resolvable by eLISA will
coalesce in the Advanced LIGO/Virgo band within ten years, allowing for
multi-band gravitational wave observations. Binaries formed via dynamical
interactions in dense star clusters are expected to have eccentricities
$e_0\sim 10^{-3}$-$10^{-1}$ at the frequencies $f_0=10^{-2}$ Hz where eLISA is
most sensitive, while binaries formed in the field should have negligible
eccentricity in both frequency bands. We estimate that eLISA should always be
able to detect a nonzero $e_0$ whenever $e_0\gtrsim 10^{-2}$; if $e_0\sim
10^{-3}$, eLISA should detect nonzero eccentricity for a fraction $\sim 90\%$
($\sim 25\%$) of binaries when the observation time is $T_{\rm obs}=5$ ($2$)
years, respectively. Therefore eLISA observations of BH binaries have the
potential to distinguish between field and cluster formation scenarios.


title:
Testing the cosmic conservation of photon number with type Ia supernovae
  and ages of old objects

abstract:
  In this paper, we obtain luminosity distances by using ages of 32 old passive
galaxies distributed over the redshift interval $0.11 < z < 1.84$ and test the
cosmic conservation of photon number by comparing them with 580 distance moduli
of type Ia supernovae (SNe Ia) from the so-called Union 2.1 compilation. Our
analyses are based on the fact that the method of obtaining ages of galaxies
relies on the detailed shape of galaxy spectra but not on galaxy luminosity.
Possible departures from cosmic conservation of photon number is parametrized
by $\tau(z) = 2 \epsilon z$ and $\tau(z) = \epsilon z/(1+z)$ (for $\epsilon =0$
the conservation of photon number is recovered). We find
$\epsilon=0.016^{+0.078}_{-0.075}$ from the first parametrization and
$\epsilon=-0.18^{+0.25}_{-0.24}$ from the second parametrization, both limits
at 95\% c.l. In this way, no significant departure from cosmic conservation of
photon number is verified. In addition, by considering the total age as
inferred from Planck (2015) analysis, we find the incubation time
$t_{inc}=1.66\pm0.29$ Gyr and $t_{inc}=1.23\pm0.27$ Gyr at 68\% c.l. for each
parametrization, respectively.}


title: Electoral Systems Used around the World

abstract:
  We give an overview of the diverse electoral systems used in local, national,
or super-national elections around the world. We discuss existing methods for
selecting single and multiple winners and give real-world examples for some
more elaborate systems. Eventually, we elaborate on some of the better known
strengths and weaknesses of various methods from both the theoretical and
practical points of view.


title: Advances in quantum metrology: Continuous variables in phase space

abstract:
  This dissertation serves as a general introduction to Wigner functions, phase
space, and quantum metrology but also strives to be useful as a how-to guide
for those who wish to delve into the realm of using continuous variables, to
describe quantum states of light and optical interferometry. We discuss the
advantages of Wigner functions and their use to describe many quantum states of
light. Throughout our metrology discussions, we will also discuss various
quantum limits and use quantum Fisher information to show optimal bounds. When
applicable, we also discuss the use of quantum Gaussian information and how it
relates to our Wigner function treatment. The remainder of our discussion
focuses on investigating the effects of photon addition and subtraction to
various states of light and analyze the nondeterministic nature of this
process. We use examples of $m$ photon additions to a coherent state as well as
discuss the properties of an $m$ photon subtracted thermal state. We also
provide an argument that this process must always be a nondeterministic one, or
the ability to violate quantum limits becomes apparent. We show that using
phase measurement as one's metric is much more restrictive, which limits the
usefulness of photon addition and subtraction. When we consider SNR however, we
show improved SNR statistics, at the cost of increased measurement time. In
this case of SNR, we also quantify the efficiency of the photon addition and
subtraction process.


title:
A Linearization Technique for Self-Interference Cancellation in
  Full-Duplex Radios

abstract:
  The fundamental problem in the design of a full-duplex radio is the
cancellation of the self-interference (SI) signal generated by the
transmitter.Current techniques for suppressing SI rely on generating a copy of
the SI signal and subtracting it partly in the RF (radio frequency) and digital
domains. A critical step in replicating the self-interference is the estimation
of the multi-path channel through which the transmitted signal propagates to
the antenna. Since there is no prior model on the number of multipath
reflections, current techniques assume a tap delay line filter (in the RF and
digital domain) with a large number of taps, and estimate the taps in the
analog and the digital domain. Assuming such a model leads to a large
form-factor for the analog and RF circuits and increased complexity in the
digital domain.
  In this paper, using a linearization technique, we show that the
self-interference channel in an indoor environment can be effectively modelled
as $H(f)=C_0 + C_1f$ in the frequency domain. Thus, the effective
self-interference channel can be represented by two parameters $C_0$ and $C_1$,
irrespective of the multipath environment. We also provide experimental
evidence to verify the above channel model and propose novel low-complexity
designs for self-interference cancellation. Linearization not only aids in the
practicality of analog cancellation by reducing the form factor, but also
results in a simpler SI filter model in the digital domain due to
dimensionality reduction of the channel parameters. Therefore this method can
enable the widespread adoption of full-duplex techniques to portable devices in
addition to infrastructure base-stations.


title:
Measurement of the Black Hole Mass in NGC 1332 from ALMA Observations at
  0.044 Arcsecond Resolution

abstract:
  We present Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 3
observations of CO(2-1) emission from the circumnuclear disk in the E/S0 galaxy
NGC 1332 at 0.044" resolution. The disk exhibits regular rotational kinematics
and central high-velocity emission (+/-500 km/s) consistent with the presence
of a compact central mass. We construct models for a thin, dynamically cold
disk in the gravitational potential of the host galaxy and black hole, and fit
the beam-smeared model line profiles directly to the ALMA data cube. Model fits
successfully reproduce the disk kinematics out to r=200 pc. Fitting models just
to spatial pixels within projected r=50 pc of the nucleus (two times larger
than the black hole's gravitational radius of influence), we find
M_BH=6.64(-0.63,+0.65)*10^8 solar masses. This observation demonstrates ALMA's
powerful capability to determine the masses of supermassive black holes by
resolving gas kinematics on small angular scales in galaxy nuclei.


title:
On the geometry of spatial biphoton correlation in spontaneous
  parametric down-conversion

abstract:
  Analytical expressions are derived for the distribution rates of spatial
coincidences in the counting of photons produced by spontaneous parametric down
conversion (SPDC). Gaussian profiles are assumed for the wave function of the
idler and signal light created in type-I SPDC. The distribution rates describe
ellipses on the detection planes that are oriented at different angles
according to the photon coincidences in either horizontal-horizontal,
vertical-vertical, horizontal-vertical or vertical-horizontal position
variables. The predictions are in agreement with the experimental data obtained
with a type-I BBO crystal that is illuminated by a 100 mW violet pump laser as
well as with the results obtained from the geometry defined by the
phase-matching conditions.


title: Private Coded Caching

abstract:
  Recent work by Maddah-Ali and Niesen introduced coded caching which
demonstrated the benefits of joint design of storage and transmission policies
in content delivery networks. They studied a setup where a server communicates
with a set of users, each equipped with a local cache, over a shared error-free
link and proposed an order-optimal caching and delivery scheme. In this paper,
we introduce the problem of secretive coded caching where we impose the
additional constraint that a user should not be able to learn anything, from
either the content stored in its cache or the server transmissions, about a
file it did not request. We propose a feasible scheme for this setting and
demonstrate its order-optimality with respect to information-theoretic lower
bounds.


title:
Lectures on Integrable probability: Stochastic vertex models and
  symmetric functions

abstract:
  We consider a homogeneous stochastic higher spin six vertex model in a
quadrant. For this model we derive concise integral representations for
multi-point q-moments of the height function and for the q-correlation
functions. At least in the case of the step initial condition, our formulas
degenerate in appropriate limits to many known formulas of such type for
integrable probabilistic systems in the (1+1)d KPZ universality class,
including the stochastic six vertex model, ASEP, various q-TASEPs, and
associated zero range processes.
  Our arguments are largely based on properties of a family of symmetric
rational functions (introduced in arXiv:1410.0976) that can be defined as
partition functions of the higher spin six vertex model for suitable domains;
they generalize classical Hall-Littlewood and Schur polynomials. A key role is
played by Cauchy-like summation identities for these functions, which are
obtained as a direct corollary of the Yang-Baxter equation for the higher spin
six vertex model.
  These are lecture notes for a course given by A.B. at the Ecole de Physique
des Houches in July of 2015. All the results and proofs presented here
generalize to the setting of the fully inhomogeneous higher spin six vertex
model, see arXiv:1601.05770 for a detailed exposition of the inhomogeneous
case.


title: On Chromatic Zagreb Indices of Certain Graphs

abstract:
  In this paper we introduce a variation of the well-known Zagreb indices by
considering a proper vertex colouring of a graph $G$. The chromatic Zagreb
indices are defined in terms of the parameter $c(v), v \in V(G)$ instead of the
invariant $d_G(v)$. The notion of chromatically stable graphs is also
introduced.


title:
Demonstration of weight-four parity measurements in the surface code
  architecture

abstract:
  We present parity measurements on a five-qubit lattice with connectivity
amenable to the surface code quantum error correction architecture. Using
all-microwave controls of superconducting qubits coupled via resonators, we
encode the parities of four data qubit states in either the $X$- or the
$Z$-basis. Given the connectivity of the lattice, we perform full
characterization of the static $Z$-interactions within the set of five qubits,
as well as dynamical $Z$-interactions brought along by single- and two-qubit
microwave drives. The parity measurements are significantly improved by
modifying the microwave two-qubit gates to dynamically remove non-ideal $Z$
errors.


title: Default Rules for Curry

abstract:
  In functional logic programs, rules are applicable independently of textual
order, i.e., any rule can potentially be used to evaluate an expression. This
is similar to logic languages and contrary to functional languages, e.g.,
Haskell enforces a strict sequential interpretation of rules. However, in some
situations it is convenient to express alternatives by means of compact default
rules. Although default rules are often used in functional programs, the
non-deterministic nature of functional logic programs does not allow to
directly transfer this concept from functional to functional logic languages in
a meaningful way. In this paper we propose a new concept of default rules for
Curry that supports a programming style similar to functional programming while
preserving the core properties of functional logic programming, i.e.,
completeness, non-determinism, and logic-oriented use of functions. We discuss
the basic concept and propose an implementation which exploits advanced
features of functional logic languages.


title: HD 35502: a hierarchical triple system with a magnetic B5IVpe primary

abstract:
  We present our analysis of HD~35502 based on high- and medium-resolution
spectropolarimetric observations. Our results indicate that the magnetic
B5IVsnp star is the primary component of a spectroscopic triple system and that
it has an effective temperature of $18.4\pm0.6\,{\rm kK}$, a mass of
$5.7\pm0.6\,M_\odot$, and a polar radius of $3.0^{+1.1}_{-0.5}\,R_\odot$. The
two secondary components are found to be essentially identical A-type stars for
which we derive effective temperatures ($8.9\pm0.3\,{\rm kK}$), masses
($2.1\pm0.2\,M_\odot$), and radii ($2.1\pm0.4\,R_\odot$). We infer a
hierarchical orbital configuration for the system in which the secondary
components form a tight binary with an orbital period of $5.66866(6)\,{\rm d}$
that orbits the primary component with a period of over $40\,{\rm yrs}$.
Least-Squares Deconvolution (LSD) profiles reveal Zeeman signatures in Stokes
$V$ indicative of a longitudinal magnetic field produced by the B star ranging
from approximately $-4$ to $0\,{\rm kG}$ with a median uncertainty of
$0.4\,{\rm kG}$. These measurements, along with the line variability produced
by strong emission in H$\alpha$, are used to derive a rotational period of
$0.853807(3)\,{\rm d}$. We find that the measured $v\sin{i}=75\pm5\,{\rm
km\,s}^{-1}$ of the B star then implies an inclination angle of the star's
rotation axis to the line of sight of $24^{+6}_{-10}\degree$. Assuming the
Oblique Rotator Model, we derive the magnetic field strength of the B star's
dipolar component ($14^{+9}_{-3}\,{\rm kG}$) and its obliquity
($63\pm13\degree$). Furthermore, we demonstrate that the calculated Alfv\'{e}n
radius ($41^{+17}_{-6}\,R_\ast$) and Kepler radius
($2.1^{+0.4}_{-0.7}\,R_\ast$) place HD~35502's central B star well within the
regime of centrifugal magnetosphere-hosting stars.


title: Modeling and Simulation of the Economics of Mining in the Bitcoin Market

abstract:
  In January 3, 2009, Satoshi Nakamoto gave rise to the "Bitcoin Block Chain"
creating the first block of the chain hashing on his computers central
processing unit (CPU). Since then, the hash calculations to mine Bitcoin have
been getting more and more complex, and consequently the mining hardware
evolved to adapt to this increasing difficulty. Three generations of mining
hardware have followed the CPU's generation. They are GPU's, FPGA's and ASIC's
generations. This work presents an agent based artificial market model of the
Bitcoin mining process and of the Bitcoin transactions. The goal of this work
is to model the economy of the mining process, starting from GPU's generation,
the first with economic significance. The model reproduces some "stylized
facts" found in real time price series and some core aspects of the mining
business. In particular, the computational experiments performed are able to
reproduce the unit root property, the fat tail phenomenon and the volatility
clustering of Bitcoin price series. In addition, under proper assumptions, they
are able to reproduce the price peak at the end of November 2013, its next fall
in April 2014, the generation of Bitcoins, the hashing capability, the power
consumption, and the mining hardware and electrical energy expenses of the
Bitcoin network.


title:
The Chromospheric Solar Limb Brightening at Radio, Millimeter,
  Sub-millimeter, and Infrared Wavelengths

abstract:
  Observations of the emission at radio, millimeter, sub-millimeter, and
infrared wavelengths in the center of the solar disk validate the
auto-consistence of semi-empirical models of the chromosphere. Theoretically,
these models must reproduce the emission at the solar limb. In this work, we
tested both the VALC and the C7 semi-empirical models by computing their
emission spectrum in the frequency range from 2 GHz to 10 THz, at solar limb
altitudes. We calculate the Sun's theoretical radii as well as their limb
brightening. Non-Local Thermodynamic Equilibrium (NLTE) was computed for
hydrogen, electron density, and H-. In order to solve the radiative transfer
equation a 3D geometry was employed to determine the ray paths and
Bremsstrahlung, H-, and inverse Bremsstrahlung opacity sources were integrated
in the optical depth. We compared the computed solar radii with high resolution
observations at the limb obtained by Clark (1994). We found that there are
differences between observed and computed solar radii of 12000 km at 20 GHz,
5000 km at 100 GHz, and 1000 km at 3 THz for both semi-empirical models. A
difference of 8000 km in the solar radii was found comparing our results
against heights obtained from H{\alpha} observations of spicules-off at the
solar limb. We conclude that the solar radii can not be reproduced by VALC and
C7 semi-empirical models at radio - infrared wavelengths. Therefore, the
structures in the high chromosphere provides a better measurement of the solar
radii and their limb brightening as shown in previous investigations.


title:
Thermodynamics of adsorption of light alkanes and alkenes in
  single-walled carbon nanotube bundles

abstract:
  The thermodynamics of adsorption of light alkanes and alkenes (CH4, C2H6,
C2H4, C3H8, and C3H6) in single-walled carbon nanotube bundles is studied by
configurational-bias grand canonical Monte Carlo simulation. The bundles
consist of uniform nanotubes with diameters in the range 11.0 < D (A) < 18.1,
arranged in the usual close-packed hexagonal lattice. The phase space is
systematically analyzed with calculations for adsorption at room temperature
and reduced pressure range of 8.7 x 10-9 < (p/p0) < 0.9. The simulation results
are interpreted in terms of the molecular nature of the adsorbate and the
corresponding solid-fluid interactions. It is shown that confinement in the
internal volume of the bundle (interstitial and intratubular) is energetically
more favorable than physisorption on the external surface (grooves and exposed
surfaces of peripheral tubes), as indicated by the curves of isosteric heat as
a function of reduced pressure. However, the zero-loading properties suggest a
crossover point to this behavior for D = 18 - 19 A. When interstitial
confinement is not inhibited by geometrical considerations, it is possible to
establish the following ordering of the zero-loading isosteric heat by type of
adsorption site.


title:
Recursion formula for the Green's function of a Hamiltonian for several
  types of Dirac delta-function potentials in curved spaces

abstract:
  In this short article, we non-perturbatively derive a recursive formula for
the Green's function associated with finitely many point Dirac delta potentials
in one dimension. We also extend this formula to the case for the Dirac delta
potentials supported by regular curves embedded in two dimensional manifolds
and for the Dirac delta potentials supported by two dimensional compact
manifolds embedded in three dimensional manifolds. Finally, this formulation
allows us to find the recursive formula of the Green's function for the point
Dirac delta potentials in two and three dimensional Riemannian manifolds, where
the renormalization of coupling constant is required.


title:
Information Geometry in Time Dependent Quantum Systems and the Geometric
  Phase

abstract:
  We study information theoretic geometry in time dependent quantum mechanical
systems. First, we discuss global properties of the parameter manifold for two
level systems exemplified by i) Rabi oscillations and ii) quenching dynamics of
the XY spin chain in a transverse magnetic field, when driven across
anisotropic criticality. Next, we comment upon the nature of the geometric
phase from classical holonomy analyses of such parameter manifolds. In the
context of the transverse XY model in the thermodynamic limit, our results are
in contradiction to those in the existing literature, and we argue why the
issue deserves a more careful analysis. Finally, we speculate on a novel
geometric phase in the model, when driven across a quantum critical line.


title:
Constancy regions of mixed multiplier ideals in two-dimensional local
  rings with rational singularities

abstract:
  The aim of this paper is to study mixed multiplier ideals associated to a
tuple of ideals in a two-dimensional local ring with a rational singularity. We
are interested in the partition of the real positive orthant given by the
regions where the mixed multiplier ideals are constant. In particular we reveal
which information encoded in a mixed multiplier ideal determines its
corresponding jumping wall and we provide an algorithm to compute all the
constancy regions, and their corresponding mixed multiplier ideals, in any
desired range.


title: Spin polarization in SCC-DFTB

abstract:
  We evaluate the performance of spin-polarized DFTB within the SCC-DFTB (also
known as DFTB2) model. The method has been implemented in the ADF modeling
suite. We briefly review how spin polarization is incorporated into the DFTB2
method and validate the method in terms of structural parameters and energy
using the GMTKN30 test set, from which we used 288 spin-polarized systems.


title: The Optimal Pessimistic Transactional Memory Algorithm

abstract:
  Transactional Memory (TM) is an approach aiming to simplify concurrent
programming by automating synchronization while maintaining efficiency. TM
usually employs the optimistic concurrency control approach, which relies on
transactions aborting and restarting if conflicts occur. However, an aborted
transaction can still leave some effects in the system that cannot be cleaned
up, if irrevocable operations are present within its code. The pessimistic
approach eliminates that problem, since it relies on deferring operations in
case of conflict rather than aborting, but hitherto pessimistic TMs suffered
from low parallelism due to the need of serializing transactions. In this
paper, we aim to introduce OptSVA, a pessimistic TM concurrency control
algorithm that ensures a high level of parallelism through a battery of
far-reaching optimizations including early release, asynchronous execution, and
the extensive use of buffering.


title:
Trace Typing: An Approach for Evaluating Retrofitted Type Systems
  (Extended Version)

abstract:
  Recent years have seen growing interest in the retrofitting of type systems
onto dynamically-typed programming languages, in order to improve type safety,
programmer productivity, or performance. In such cases, type system developers
must strike a delicate balance between disallowing certain coding patterns to
keep the type system simple, or including them at the expense of additional
complexity and effort. Thus far, the process for designing retrofitted type
systems has been largely ad hoc, because evaluating multiple variations of a
type system on large bodies of existing code is a significant undertaking.
  We present trace typing: a framework for automatically and quantitatively
evaluating variations of a retrofitted type system on large code bases. The
trace typing approach involves gathering traces of program executions,
inferring types for instances of variables and expressions occurring in a
trace, and merging types according to merge strategies that reflect specific
(combinations of) choices in the source-level type system design space.
  We evaluated trace typing through several experiments. We compared several
variations of type systems retrofitted onto JavaScript, measuring the number of
program locations with type errors in each case on a suite of over fifty
thousand lines of JavaScript code. We also used trace typing to validate and
guide the design of a new retrofitted type system that enforces fixed object
layout for JavaScript objects. Finally, we leveraged the types computed by
trace typing to automatically identify tag tests --- dynamic checks that refine
a type --- and examined the variety of tests identified.


title:
Vector and Axial-vector resonances in composite models of the Higgs
  boson

abstract:
  We provide a non-linear realisation of composite Higgs models in the context
of the SU(4)/Sp(4) symmetry breaking pattern, where the effective Lagrangian of
the spin-0 and spin-1 resonances is constructed via the CCWZ prescription using
the Hidden Symmetry formalism. We investigate the EWPT constraints by
accounting the effects from reduced Higgs couplings and integrating out heavy
spin-1 resonances. This theory emerges from an underlying theory of gauge
interactions with fermions, thus first principle lattice results predict the
massive spectrum in composite Higgs models. This model can be used as a
template for the phenomenology of composite Higgs models at the LHC and at
future 100 TeV colliders, as well as for other application. In this work, we
focus on the formalism for spin-1 resonances and their bounds from di-lepton
and di-boson searches at the LHC.


title: ISS in Different Norms for 1-D Parabolic PDES With Boundary Disturbances

abstract:
  For 1-D parabolic PDEs with disturbances at both boundaries and distributed
disturbances we provide ISS estimates in various norms. Due to the lack of an
ISS Lyapunov functional for boundary disturbances, the proof methodology uses
(i) an eigenfunction expansion of the solution, and (ii) a finite-difference
scheme. The ISS estimate for the sup-norm leads to a refinement of the
well-known maximum principle for the heat equation. Finally, the obtained
results are applied to quasi-static thermoelasticity models that involve
nonlocal boundary conditions. Small-gain conditions that guarantee the global
exponential stability of the zero solution for such models are derived.


title: On the Macroscopic Fractal Geometry of Some Random Sets

abstract:
  This paper is concerned mainly with the macroscopic fractal behavior of
various random sets that arise in modern and classical probability theory.
Among other things, it is shown here that the macroscopic behavior of Boolean
coverage processes is analogous to the microscopic structure of the Mandelbrot
fractal percolation. Other, more technically challenging, results of this paper
include: (i) The computation of the macroscopic dimension of the graph of a
large family of L\'evy processes; and (ii) The determination of the macroscopic
monofractality of the extreme values of symmetric stable processes.
  As a consequence of (i), it will be shown that the macroscopic fractal
dimension of the graph of Brownian motion differs from its microscopic fractal
dimension. Thus, there can be no scaling argument that allows one to deduce the
macroscopic geometry from the microscopic. Item (ii) extends the recent work of
Khoshnevisan, Kim, and Xiao \cite{KKX} on the extreme values of Brownian
motion, using a different method.


title:
Nanoscopic Characterization of DNA within Hydrophobic
  Pores:Thermodynamics and Kinetics

abstract:
  The energetic and transport properties of a double-stranded DNA dodecamer
encapsulated in hydrophobic carbon nanotubes are probed employing two limiting
nanotube diameters, D=4 nm and D=3 nm, corresponding to (51,0) and (40,0)
zig-zag topologies, respectively. It is observed that the thermodynamically
spontaneous encapsulation in the 4 nm nanopore (40 kJ/mol) is annihilated when
the solid diameter narrows down to 3 nm, and that the confined DNA termini
directly contact the hydrophobic walls with no solvent slab in-between. During
the initial moments after confinement (2-3 ns),the biomolecule translocates
along the nano pore's inner volume according to Fick's law (t) with a
self-diffusion coefficient D=1.713 x 10-9m2/s, after which molecular diffusion
assumes a single-file type mechanism (t1/2). As expected, diffusion is
anisotropic, with the pore main axis as the preferred direction, but an
in-depth analysis shows that the instantaneous velocity probabilities are
essentially identical along the x, y and z directions. The 3D velocity
histogram shows a maximum probability located at v=30.8 m/s, twice the observed
velocity for a single-stranded three nucleotide DNA encapsulated in comparable
armchair geometries (v=16.7 m/s, D=1.36-1.89 nm). Because precise physiological
conditions (310 K, [NaCl] = 134 mM) are employed throughout, the present study
establishes a landmark for the development of next generation in vivo drug
delivery technologies based on carbon nanotubes as encapsulation agents.


title: Monodromy Dark Matter

abstract:
  Light pseudo-Nambu-Goldstone bosons (pNGBs) such as, e.g.~axion-like
particles, that are non-thermally produced via the misalignment mechanism are
promising dark matter candidates. An important feature of pNGBs is their
periodic potential, whose scale of periodicity controls all their couplings. As
a consequence of the periodicity the maximal potential energy is limited and,
hence, producing the observed dark matter density poses significant constraints
on the allowed masses and couplings. In the presence of a monodromy, the field
range as well as the range of the potential can be significantly extended. As
we argue in this paper this has important phenomenological consequences. The
constraints on the masses and couplings are ameliorated and couplings to
Standard Model particles could be significantly stronger, thereby opening up
considerable experimental opportunities. Yet, monodromy models can also give
rise to new and qualitatively different features. As a remnant of the
periodicity the potential can feature pronounced wiggles. When the field is
passing through them quantum fluctuations are enhanced and particles with
non-vanishing momentum are produced. Here, we perform a first analysis of this
effect and delineate under which circumstances this becomes important. We
discuss possible cosmological consequences.


title:
Unsupervised Total Variation Loss for Semi-supervised Deep Learning of
  Semantic Segmentation

abstract:
  We introduce a novel unsupervised loss function for learning semantic
segmentation with deep convolutional neural nets (ConvNet) when densely labeled
training images are not available. More specifically, the proposed loss
function penalizes the L1-norm of the gradient of the label probability vector
image , i.e. total variation, produced by the ConvNet. This can be seen as a
regularization term that promotes piecewise smoothness of the label probability
vector image produced by the ConvNet during learning. The unsupervised loss
function is combined with a supervised loss in a semi-supervised setting to
learn ConvNets that can achieve high semantic segmentation accuracy even when
only a tiny percentage of the pixels in the training images are labeled. We
demonstrate significant improvements over the purely supervised setting in the
Weizmann horse, Stanford background and Sift Flow datasets. Furthermore, we
show that using the proposed piecewise smoothness constraint in the learning
phase significantly outperforms post-processing results from a purely
supervised approach with Markov Random Fields (MRF). Finally, we note that the
framework we introduce is general and can be used to learn to label other types
of structures such as curvilinear structures by modifying the unsupervised loss
function accordingly.


title: Accelerating Deep Learning with Shrinkage and Recall

abstract:
  Deep Learning is a very powerful machine learning model. Deep Learning trains
a large number of parameters for multiple layers and is very slow when data is
in large scale and the architecture size is large. Inspired from the shrinking
technique used in accelerating computation of Support Vector Machines (SVM)
algorithm and screening technique used in LASSO, we propose a shrinking Deep
Learning with recall (sDLr) approach to speed up deep learning computation. We
experiment shrinking Deep Learning with recall (sDLr) using Deep Neural Network
(DNN), Deep Belief Network (DBN) and Convolution Neural Network (CNN) on 4 data
sets. Results show that the speedup using shrinking Deep Learning with recall
(sDLr) can reach more than 2.0 while still giving competitive classification
performance.


title: Visualizing acoustical beats with a smartphones

abstract:
  In this work, a new Physics laboratory experiment on Acoustics beats is
presented. We have designed a simple experimental setup to study superposition
of sound waves of slightly different frequencies (acoustic beat). The
microphone of a smartphone is used to capture the sound waves emitted by two
equidistant speakers from the mobile which are at the same time connected to
two AC generators. The smartphone is used as a measuring instrument. By means
of a simple and free AndroidTM application, the sound level (in dB) as a
function of time is measured and exported to a .csv format file. Applying
common graphing analysis and a fitting procedure, the frequency of the beat is
obtained. The beat frequencies as obtained from the smartphone data are
compared with the difference of the frequencies set at the AC generator. A very
good agreement is obtained being the percentage discrepancies within 1 %.


title: Expect at most one billionth of a new Fermat Prime!

abstract:
  We provide compelling evidence that all Fermat primes were already known to
Fermat.


title:
Theoretical and experimental study of the normal modes in a coupled
  two-dimensional system

abstract:
  In this work, the normal modes of a two-dimensional oscillating system have
been studied from a theoretical and experimental point of view. The normal
frequencies predicted by the Hessian matrix for a coupled two-dimensional
particle system are compared to those obtained for a real system consisting of
two oscillating smartphones coupled one to the other by springs. Experiments
are performed on an air table in order to remove the friction forces. The
oscillation data are captured by the acceleration sensor of the smartphones and
exported to file for further analysis. The experimental frequencies compare
reasonably well with the theoretical predictions, namely, within 1.7 % of
discrepancy.


title:
Simple transitive 2-representations of small quotients of Soergel
  bimodules

abstract:
  In all finite Coxeter types but $I_2(12)$, $I_2(18)$ and $I_2(30)$, we
classify simple transitive $2$-rep\-re\-sen\-ta\-ti\-ons for the quotient of
the $2$-category of Soergel bimodules over the coinvariant algebra which is
associated to the two-sided cell that is the closest one to the two-sided cell
containing the identity element. It turns out that, in most of the cases,
simple transitive $2$-representations are exhausted by cell
$2$-representations. However, in Coxeter types $I_2(2k)$, where $k\geq 3$,
there exist simple transitive $2$-representations which are not equivalent to
cell $2$-representations.


title: Remarks of weak-compactness along Kahler Ricci flow

abstract:
  We provide a direct proof of time-slice weak compactness along the K\"ahler
Ricci flow on Fano manifolds.


title: Fermi Reveals New Light on Novae in Gamma rays

abstract:
  Novae are now firmly established as a high-energy (>100 MeV) gamma-ray source
class by the Fermi Large Area Telescope (LAT). In symbiotic binary systems such
as V407 Cyg 2010, there is a firm theoretical framework for the production of
shock-accelerated particles in the nova ejecta from interactions with the dense
wind of the red giant companion. Yet, the high-energy gamma-ray emission
detected in classical novae involving less evolved stellar companions cannot be
explained in the same way and could instead be produced in internal shocks in
the ejecta. We summarize the Fermi-LAT gamma-ray observations of novae,
highlighting the main properties that will guide further studies. Additionally,
we report on the soft gamma-ray (~0.1 MeV) continuum detection of the
oxygen-neon type classical nova V382 Vel 1999 with the OSSE detector aboard the
Compton Gamma Ray Observatory in light of its Fermi-era analog, V959 Mon 2012.


title:
Hopf Algebroid Twists for Deformation Quantization of Linear Poisson
  Structures

abstract:
  In our earlier article [Lett. Math. Phys. 107 (2017), 475-503,
arXiv:1409.8188], we explicitly described a topological Hopf algebroid playing
the role of the noncommutative phase space of Lie algebra type. Ping Xu has
shown that every deformation quantization leads to a Drinfeld twist of the
associative bialgebroid of h-adic series of differential operators on a fixed
Poisson manifold. In the case of linear Poisson structures, the twisted
bialgebroid essentially coincides with our construction. Using our explicit
description of the Hopf algebroid, we compute the corresponding Drinfeld twist
explicitly as a product of two exponential expressions.


title: Shape minimization problems in liquid crystals

abstract:
  We consider a class of liquid crystal free-boundary problems for which both
the equilibrium shape and internal configuration of a system must
simultaneously be determined, for example in films with air- or fluid-liquid
crystal interfaces and elastomers. We develop a finite element algorithm to
solve such problems with dynamic mesh control, achieved by supplementing the
free energy with an auxiliary functional that promotes mesh quality and is
minimized in the null space of the energy. We apply this algorithm to a
flexible capacitor, as well as to determine the shape of liquid crystal
tactoids as a function of the surface tension and elastic constants. These are
compared with theoretical predictions and experimental observations of tactoids
from the literature.


title: Comparing the diversity of information by word-of-mouth vs. web spread

abstract:
  Many studies have explored spreading and diffusion through complex networks.
The following study examines a specific case of spreading of opinions in modern
society through two spreading schemes, defined as being either through
word-of-mouth (WOM), or through online search engines (WEB). We apply both
modelling and real experimental results and compare the opinions people adopt
through an exposure to their friend`s opinions, as opposed to the opinions they
adopt when using a search engine based on the PageRank algorithm. A simulated
study shows that when members in a population adopt decisions through the use
of the WEB scheme, the population ends up with a few dominant views, while
other views are barely expressed. In contrast, when members adopt decisions
based on the WOM scheme, there is a far more diverse distribution of opinions
in that population. The simulative results are further supported by an online
experiment which finds that people searching information through a search
engine end up with far more homogenous opinions as compared to those asking
their friends.


title: Leveraging Visual Question Answering for Image-Caption Ranking

abstract:
  Visual Question Answering (VQA) is the task of taking as input an image and a
free-form natural language question about the image, and producing an accurate
answer. In this work we view VQA as a "feature extraction" module to extract
image and caption representations. We employ these representations for the task
of image-caption ranking. Each feature dimension captures (imagines) whether a
fact (question-answer pair) could plausibly be true for the image and caption.
This allows the model to interpret images and captions from a wide variety of
perspectives. We propose score-level and representation-level fusion models to
incorporate VQA knowledge in an existing state-of-the-art VQA-agnostic
image-caption ranking model. We find that incorporating and reasoning about
consistency between images and captions significantly improves performance.
Concretely, our model improves state-of-the-art on caption retrieval by 7.1%
and on image retrieval by 4.4% on the MSCOCO dataset.


title: Two loop correction to interference in $gg \to ZZ$

abstract:
  We present results for the production of a pair of on-shell Z bosons via
gluon fusion. This process occurs both through the production and decay of the
Higgs boson, and through continuum production where the Z boson couples to a
loop of massless quarks or to a massive quark. We calculate the interference of
the two processes and its contribution to the cross section up to and including
order O(alpha_s^3). The two-loop contributions to the amplitude are all known
analytically, except for the continuum production through loops of top quarks
of mass m. The latter contribution is important for the invariant mass of the
two Z bosons, (as measured by the mass of their leptonic decay products, m_4l),
in a regime where m_4l > 2m because of the contributions of longitudinal
bosons. We examine all the contributions to the virtual amplitude involving top
quarks, as expansions about the heavy top quark limit. Comparison with the
analytic results, where known, allows us to assess the validity of the heavy
quark expansion, and it extensions. We give results for the NLO corrections to
this interference, including both real and virtual radiation.


title: Review of analytical instruments for EEG analysis

abstract:
  Since it was first used in 1926, EEG has been one of the most useful
instruments of neuroscience. In order to start using EEG data we need not only
EEG apparatus, but also some analytical tools and skills to understand what our
data mean. This article describes several classical analytical tools and also
new one which appeared only several years ago. We hope it will be useful for
those researchers who have only started working in the field of cognitive EEG.


title:
An Empirical Determination of the Intergalactic Background Light from UV
  to FIR Wavelengths Using FIR Deep Galaxy Surveys and the Gamma-ray Opacity of
  the Universe

abstract:
  We have previously calculated the intergalactic background light (IBL) as a
function of redshift in the far ultraviolet to near infrared range, based
purely on data from deep galaxy surveys. Here we utilize similar methods to
determine the mid- and far infrared IBL out to a wavelength of 850 microns. Our
approach enables us to constrain the range of photon densities, based on the
uncertainties from observationally determined luminosity densities and colors.
By also including the effect of the 2.7 K cosmic background photons, we
determine 68% confidence upper and lower limits on the opacity of the universe
to gamma-rays up to PeV energies. Our direct results on the IBL are consistent
with those from complimentary gamma-ray analyses using observations from the
Fermi $\gamma$-ray space telescope and the H.E.S.S. air Cherenkov telescope.
Thus, we find no evidence of previously suggested processes for the
modification of gamma-ray spectra other than that of absorption by pair
production alone.


title:
Loop quantum cosmology of Bianchi IX: Inclusion of inverse triad
  corrections

abstract:
  We consider the loop quantization of the (diagonal) Bianchi type IX
cosmological model. We explore different quantization prescriptions that extend
the work of Wilson-Ewing and Singh. In particular, we study two different ways
of implementing the so-called inverse triad corrections. We construct the
corresponding Hamiltonian constraint operators and show that the singularity is
formally resolved. We find the effective equations associated with the
different quantization prescriptions, and study the relation with the isotropic
$k$=1 model that, classically, is contained within the Bianchi IX model. We use
geometrically defined scalar observables to explore the physical implications
of each of these theories. This is the first part in a series of papers
analyzing different aspects of the Bianchi IX model, with inverse corrections,
within loop quantum cosmology.


title:
Multilevel Monte Carlo methods for the approximation of invariant
  measures of stochastic differential equations

abstract:
  We develop a framework that allows the use of the multi-level Monte Carlo
(MLMC) methodology (Giles2015) to calculate expectations with respect to the
invariant measure of an ergodic SDE. In that context, we study the
(over-damped) Langevin equations with a strongly concave potential. We show
that, when appropriate contracting couplings for the numerical integrators are
available, one can obtain a uniform in time estimate of the MLMC variance in
contrast to the majority of the results in the MLMC literature. As a
consequence, a root mean square error of $\mathcal{O}(\varepsilon)$ is achieved
with $\mathcal{O}(\varepsilon^{-2})$ complexity on par with Markov Chain Monte
Carlo (MCMC) methods, which however can be computationally intensive when
applied to large data sets. Finally, we present a multi-level version of the
recently introduced Stochastic Gradient Langevin Dynamics (SGLD) method
(Welling and Teh, 2011) built for large datasets applications. We show that
this is the first stochastic gradient MCMC method with complexity
$\mathcal{O}(\varepsilon^{-2}|\log {\varepsilon}|^{3})$, in contrast to the
complexity $\mathcal{O}(\varepsilon^{-3})$ of currently available methods.
Numerical experiments confirm our theoretical findings.


title: Shift-preserving maps on $\omega^*$

abstract:
  The shift map $\sigma$ on $\omega^*$ is the continuous self-map of $\omega^*$
induced by the function $n \mapsto n+1$ on $\omega$. Given a compact Hausdorff
space $X$ and a continuous function $f: X \rightarrow X$, we say that $(X,f)$
is a quotient of $(\omega^*,\sigma)$ whenever there is a continuous surjection
$Q: \omega^* \to X$ such that $Q \circ \sigma = f \circ Q$.
  Our main theorem states that if the weight of $X$ is at most $\aleph_1$, then
$(X,f)$ is a quotient of $(\omega^*,\sigma)$ if and only if $f$ is weakly
incompressible (which means that no nontrivial open $U \subseteq X$ has
$f(\bar{U}) \subseteq U$). Under CH, this gives a complete characterization of
the quotients of $(\omega^*,\sigma)$ and implies, for example, that
$(\omega^*,\sigma^{-1})$ is a quotient of $(\omega^*,\sigma)$.
  In the language of topological dynamics, our theorem states that a dynamical
system of weight $\aleph_1$ is an abstract $\omega$-limit set if and only if it
is weakly incompressible.
  We complement these results by proving $(1)$ our main theorem remains true
when $\aleph_1$ is replaced by any $\kappa < \mathfrak{p}$, $(2)$ consistently,
the theorem becomes false if we replace $\aleph_1$ by $\aleph_2$, and $(3)$
OCA+MA implies that $(\omega^*,\sigma^{-1})$ is not a quotient of
$(\omega^*,\sigma)$.


title: Composite operators and form factors in N=4 SYM

abstract:
  We construct the most general composite operators of N = 4 SYM in Lorentz
harmonic chiral ($\approx$ twistor) superspace. The operators are built from
the SYM supercurvature which is nonpolynomial in the chiral gauge
prepotentials. We reconstruct the full nonchiral dependence of the
supercurvature. We compute all tree-level MHV form factors via the LSZ
redcution procedure with on-shell states made of the same supercurvature.


title:
Fixation probabilities for any configuration of two strategies on
  regular graphs

abstract:
  Population structure and spatial heterogeneity are integral components of
evolutionary dynamics, in general, and of evolution of cooperation, in
particular. Structure can promote the emergence of cooperation in some
populations and suppress it in others. Here, we provide results for weak
selection to favor cooperation on regular graphs for any configuration, meaning
any arrangement of cooperators and defectors. Our results extend previous work
on fixation probabilities of single, randomly placed mutants. We find that for
any configuration cooperation is never favored for birth-death (BD) updating.
In contrast, for death-birth (DB) updating, we derive a simple, computationally
tractable formula for weak selection to favor cooperation when starting from
any configuration containing any number of cooperators and defectors. This
formula elucidates two important features: (i) the takeover of cooperation can
be enhanced by the strategic placement of cooperators and (ii) adding more
cooperators to a configuration can sometimes suppress the evolution of
cooperation. These findings give a formal account for how selection acts on all
transient states that appear in evolutionary trajectories. They also inform the
strategic design of initial states in social networks to maximally promote
cooperation. We also derive general results that characterize the interaction
of any two strategies, not only cooperation and defection.


title:
Arctic curves of the six-vertex model on generic domains: the Tangent
  Method

abstract:
  We revisit the problem of determining the Arctic curve in the six-vertex
model with domain wall boundary conditions. We describe an alternative method,
by which we recover the previously conjectured analytic expression in the
square domain. We adapt the method to work for a large class of domains, and
for other models exhibiting limit shape phenomena. We study in detail some
examples, and derive, in particular, the Arctic curve of the six-vertex model
in a triangoloid domain at the ice-point.

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


title: Heavy ions at the Future Circular Collider

abstract:
  The Future Circular Collider (FCC) Study is aimed at assessing the physics
potential and the technical feasibility of a new collider with centre-of-mass
energies, in the hadron-hadron collision mode, seven times larger than the
nominal LHC energies. Operating such machine with heavy ions is an option that
is being considered in the accelerator design studies. It would provide, for
example, Pb-Pb and p-Pb collisions at sqrt{s_NN} = 39 and 63 TeV, respectively,
per nucleon-nucleon collision, with integrated luminosities above 30 nb^-1 per
month for Pb-Pb. This is a report by the working group on heavy-ion physics of
the FCC Study. First ideas on the physics opportunities with heavy ions at the
FCC are presented, covering the physics of the Quark-Gluon Plasma, of gluon
saturation, of photon-induced collisions, as well as connections with other
fields of high-energy physics.


title: Interaction-tuned Anderson versus Mott localization

abstract:
  Disorder or sufficiently strong interactions can render a metallic state
unstable causing it to turn into an insulating one. Despite the fact that the
interplay of these two routes to a vanishing conductivity has been a central
research topic, a unifying picture has not emerged so far. Here, we establish
that the two-dimensional Falicov-Kimball model, one of the simplest lattice
models of strong electron correlation does allow for the study of this
interplay. In particular, we show that this model at particle-hole symmetry
possesses three distinct thermodynamic insulating phases and exhibits Anderson
localization. The previously reported metallic phase is identified as a
finite-size feature due to the presence of weak localization. We characterize
these phases by their electronic density of states, staggered occupation,
conductivity, and the generalized inverse participation ratio. The implications
of our findings for other strongly correlated systems are discussed.


title: Higher enveloping algebras

abstract:
  We provide spectral Lie algebras with enveloping algebras over the operad of
little $G$-framed $n$-dimensional disks for any choice of dimension $n$ and
structure group $G$, and we describe these objects in two complementary ways.
The first description is an abstract characterization by a universal mapping
property, which witnesses the higher enveloping algebra as the value of a left
adjoint in an adjunction. The second, a generalization of the
Poincar\'{e}-Birkhoff-Witt theorem, provides a concrete formula in terms of Lie
algebra homology. Our construction pairs the theories of Koszul duality and Day
convolution in order to lift to the world of higher algebra the fundamental
combinatorics of Beilinson-Drinfeld's theory of chiral algebras. Like that
theory, ours is intimately linked to the geometry of configuration spaces and
has the study of these spaces among its applications. We use it here to show
that the stable homotopy types of configuration spaces are proper homotopy
invariants.


title:
A bias to CMB lensing measurements from the bispectrum of large-scale
  structure

abstract:
  The rapidly improving precision of measurements of gravitational lensing of
the Cosmic Microwave Background (CMB) also requires a corresponding increase in
the precision of theoretical modeling. A commonly made approximation is to
model the CMB deflection angle or lensing potential as a Gaussian random field.
In this paper, however, we analytically quantify the influence of the
non-Gaussianity of large-scale structure lenses, arising from nonlinear
structure formation, on CMB lensing measurements. In particular, evaluating the
impact of the non-zero bispectrum of large-scale structure on the relevant CMB
four-point correlation functions, we find that there is a bias to estimates of
the CMB lensing power spectrum. For temperature-based lensing reconstruction
with CMB Stage-III and Stage-IV experiments, we find that this lensing power
spectrum bias is negative and is of order one percent of the signal. This
corresponds to a shift of multiple standard deviations for these upcoming
experiments. We caution, however, that our numerical calculation only evaluates
two of the largest bias terms and thus only provides an approximate estimate of
the full bias. We conclude that further investigation into lensing biases from
nonlinear structure formation is required and that these biases should be
accounted for in future lensing analyses.


title: The Last Minutes of Oxygen Shell Burning in a Massive Star

abstract:
  We present the first 3D simulation of the last minutes of oxygen shell
burning in an 18 solar mass supernova progenitor up to the onset of core
collapse. A moving inner boundary is used to accurately model the contraction
of the silicon and iron core according to a 1D stellar evolution model with a
self-consistent treatment of core deleptonization and nuclear
quasi-equilibrium. The simulation covers the full solid angle to allow the
emergence of large-scale convective modes. Due to core contraction and the
concomitant acceleration of nuclear burning, the convective Mach number
increases to ~0.1 at collapse, and an l=2 mode emerges shortly before the end
of the simulation. Aside from a growth of the oxygen shell from 0.51 to 0.56
solar masses due to entrainment from the carbon shell, the convective flow is
reasonably well described by mixing length theory, and the dominant scales are
compatible with estimates from linear stability analysis. We deduce that
artificial changes in the physics, such as accelerated core contraction, can
have precarious consequences for the state of convection at collapse. We argue
that scaling laws for the convective velocities and eddy sizes furnish good
estimates for the state of shell convection at collapse and develop a simple
analytic theory for the impact of convective seed perturbations on shock
revival in the ensuing supernova. We predict a reduction of the critical
luminosity for explosion by 12--24% due to seed asphericities for our 3D
progenitor model relative to the case without large seed perturbations.


title:
The Availability and Security Implications of Glue in the Domain Name
  System

abstract:
  The Domain Name System (DNS) is one of the most fundamental components of the
Internet. While glue is widely used and heavily relied on in DNS operations,
there is little thinking about the necessity, complexity, and venerability of
such prevalent configuration. This work is the first to provide extensive and
systematic analysis of DNS glue. It discusses the availability implications of
glue and proposes the minimum glue records in terms of availability. It also
identifies the security vulnerabilities of glue as well as the limitations of
current countermeasures. Measurements show the wide occurrences of glue
redundancies and glue vulnerabilities.


title: Viscoplastic flow in an extrusion damper

abstract:
  Numerical simulations of the flow in an extrusion damper are performed using
a finite volume method. The damper is assumed to consist of a shaft, with or
without a spherical bulge, oscillating axially in a containing cylinder filled
with a viscoplastic material of Bingham type. The response of the damper to a
forced sinusoidal displacement is studied. In the bulgeless case the
configuration is the annular analogue of the well-known lid-driven cavity
problem, but with a sinusoidal rather than constant lid velocity. Navier slip
is applied to the shaft surface in order to bound the reaction force to finite
values. Starting from a base case, several problem parameters are varied in
turn in order to study the effects of viscoplasticity, slip, damper geometry
and oscillation frequency to the damper response. The results show that,
compared to Newtonian flow, viscoplasticity causes the damper force to be less
sensitive to the shaft velocity; this is often a desirable damper property. The
bulge increases the required force on the damper mainly by generating a
pressure difference across itself; the latter is larger the smaller the gap
between the bulge and the casing is. At high yield stresses or slip
coefficients the amount of energy dissipation that occurs due to sliding
friction at the shaft-fluid interface is seen to increase significantly. At low
frequencies the flow is in quasi steady state, dominated by viscoplastic
forces, while at higher frequencies the fluid kinetic energy storage and
release also come into the energy balance, introducing hysteresis effects.


title: Squares that Look Round: Transforming Spherical Images

abstract:
  We propose M\"obius transformations as the natural rotation and scaling tools
for editing spherical images. As an application we produce spherical Droste
images. We obtain other self-similar visual effects using rational functions,
elliptic functions, and Schwarz-Christoffel maps.


title:
Skin Lesion Analysis toward Melanoma Detection: A Challenge at the
  International Symposium on Biomedical Imaging (ISBI) 2016, hosted by the
  International Skin Imaging Collaboration (ISIC)

abstract:
  In this article, we describe the design and implementation of a publicly
accessible dermatology image analysis benchmark challenge. The goal of the
challenge is to sup- port research and development of algorithms for automated
diagnosis of melanoma, a lethal form of skin cancer, from dermoscopic images.
The challenge was divided into sub-challenges for each task involved in image
analysis, including lesion segmentation, dermoscopic feature detection within a
lesion, and classification of melanoma. Training data included 900 images. A
separate test dataset of 379 images was provided to measure resultant
performance of systems developed with the training data. Ground truth for both
training and test sets was generated by a panel of dermoscopic experts. In
total, there were 79 submissions from a group of 38 participants, making this
the largest standardized and comparative study for melanoma diagnosis in
dermoscopic images to date. While the official challenge duration and ranking
of participants has concluded, the datasets remain available for further
research and development.


title: Maximal Sfermion Flavor Violation in Super-GUTs

abstract:
  We consider supersymmetric grand unified theories with soft
supersymmetry-breaking scalar masses $m_0$ specified above the GUT scale
(super-GUTs) and patterns of Yukawa couplings motivated by upper limits on
flavour-changing interactions beyond the Standard Model. If the scalar masses
are smaller than the gaugino masses $m_{1/2}$, as is expected in no-scale
models, the dominant effects of renormalization between the input scale and the
GUT scale are generally expected to be those due to the gauge couplings, which
are proportional to $m_{1/2}$ and generation-independent. In this case, the
input scalar masses $m_0$ may violate flavour maximally, a scenario we call
MaxSFV, and there is no supersymmetric flavour problem. We illustrate this
possibility within various specific super-GUT scenarios that are deformations
of no-scale gravity.


title:
The Influence of Temperature Anisotropies in Controlling the Development
  of Magnetospheric Substorms

abstract:
  Ion anisotropies can affect a host of processes within the magnetosphere,
from modifying the growth rate of various instabilities to the energization and
mass transport within the magnetosphere. Global multi-fluid simulations using a
full treatment of the pressure tensor are used to evaluate the influence of
temperature anisotropies on the magnetospheric dynamics for an idealized
substorm. The simulations are able to resolve the development of conics over
the polar cap which eventually turn into beams in the lobes. Entry of this
plasma, particularly heavy ions with high Tparallel, leads to a faster
reconnection rate, additional turbulence within the reconnection region, and
the substorm onset time occurs approximately 5 min earlier relative to
isotropic simulations. The anisotropic treatment yields much more intense
auroral currents on the nightside associated with onset and a faster expansion
phase of the substorm. The plasma entering into the current sheet experiences
stronger heating in the anisotropic simulations, which increases plasma
transport into the equatorial dayside. Hence, the convection of the
plasmasphere towards the dayside magnetosphere during the growth phase is
accompanied by a relative increase in Tparallel. This leads to a very distinct
temperature profile on the dayside. The injection of the energetic particles
from the substorm leads to an overall increase Tperpendicular on the dayside,
but only O+ reaches sufficient energies for the bulk of these ions to be able
to cross noon local time during the expansion phase to participate in the
formation of symmetric ring current. The net effect from these processes is to
decrease the cross-polar cap potential, modify the timing of the development of
reconnection and the development of the auroral currents and enhance the
injection of energetic particles into the inner magnetosphere.


title: Conditional measures of determinantal point processes

abstract:
  For a class of one-dimensional determinantal point processes including those
induced by orthogonal projections with integrable kernels satisfying a growth
condition, it is proved that their conditional measures, with respect to the
configuration in the complement of a compact interval, are orthogonal
polynomial ensembles with explicitly found weights. Examples include the
sine-process and the process with the Bessel kernel. The argument uses the
quasi-invariance, established in [1], of our point processes under the group of
piecewise isometries of the real line.


title: Combating Malicious DNS Tunnel

abstract:
  This paper proposes a defense scheme against malicious use of DNS tunnel. A
tunnel validator is designed to provide trustworthy tunnel-aware defensive
recursive service. In addition to the detection algorithm of malicious tunnel
domains, the tunnel validation relies on registered tunnel domains as whitelist
and identified malicious tunnel domains as blacklist. A benign tunnel user is
thus motivated to register its tunnel domain before using it. Through the
tunnel validation, the secure domains are allowed to the recursive service
provided by the tunnel validator and the insecure domains are blocked. All
inbound suspicious DNS queries are recorded and stored for forensics and future
malicious tunnel detection by the tunnel validator.


title:
Challenging Fuel Cycle Modeling Assumptions: Facility and Time Step
  Discretization Effects

abstract:
  Due to the diversity of fuel cycle simulator modeling assumptions, direct
comparison and benchmarking can be difficult. In 2012 the Organisation for
Economic Co-operation and Development completed a benchmark study that is
perhaps the most complete published comparison performed. Despite this, various
results from the simulators were often significantly different because of
inconsistencies in modeling decisions involving reprocessing strategies,
refueling behavior, reactor end-of-life handling, etc. This work identifies and
quantifies the effects of selected modeling choices that may sometimes be taken
for granted in the fuel cycle simulation domain. Four scenarios are compared
using combinations of fleet-based or individually modeled reactors with monthly
or quarterly (3-month) time steps. The scenarios approximate a transition from
the current U.S. once-through light water reactor fleet to a full sodium fast
reactor fuel cycle. The Cyclus fuel cycle simulator's plug-in capability along
with its market-like dynamic material routing allow it to be used as a level
playing field for comparing the scenarios. When under supply-constraint
pressure, the four cases exhibit noticeably different behavior. Fleet-based
modeling is more efficient in supply-constrained environments at the expense of
losing insight on issues such as realistically suboptimal fuel distribution and
challenges in reactor refueling cycle staggering. Finer-grained time steps
enable more efficient material use in supply-constrained environments resulting
in lower standing inventories of separated Pu. Large simulations with
fleet-based reactors run much more quickly than their individual reactor
counterparts. Gaining a better understanding of how these and other modeling
choices affect fuel cycle dynamics will enable making more deliberate decisions
with respect to trade-offs such as computational investment vs. realism.


title: Gravitational waves from bubble collisions: analytic derivation

abstract:
  We consider gravitational wave production by bubble collisions during a
cosmological first-order phase transition. In the literature, such spectra have
been estimated by simulating the bubble dynamics, under so-called thin-wall and
envelope approximations in a flat background metric. However, we show that,
within these assumptions, the gravitational wave spectrum can be estimated in
an analytic way. Our estimation is based on the observation that the two-point
correlator of the energy-momentum tensor $\langle T(x)T(y)\rangle$ can be
expressed analytically under these assumptions. Though the final expressions
for the spectrum contain a few integrations that cannot be calculated
explicitly, we can easily estimate it numerically. As a result, it is found
that the most of the contributions to the spectrum come from single-bubble
contribution to the correlator, and in addition the fall-off of the spectrum at
high frequencies is found to be proportional to $f^{-1}$. We also provide
fitting formulae for the spectrum.


title:
The holographic dual of a Riemann problem in a large number of
  dimensions

abstract:
  We study properties of a non equilibrium steady state generated when two heat
baths are initially in contact with one another. The dynamics of the system we
study are governed by holographic duality in a large number of dimensions. We
discuss the "phase diagram" associated with the steady state; the dual,
dynamical, black hole description of this problem; and its relation to the
fluid/gravity correspondence.


title: Determining the progenitors of merging black-hole binaries

abstract:
  We investigate a possible method for determining the progenitors of black
hole (BH) mergers observed via their gravitational wave (GW) signal. We argue
that measurements of the cross-correlation of the GW events with overlapping
galaxy catalogs may provide an additional tool in determining if BH mergers
trace the stellar mass of the Universe, as would be expected from mergers of
the endpoints of stellar evolution. If on the other hand the BHs are of
primordial origin, as has been recently suggested, their merging would be
preferentially hosted by lower biased objects, and thus have a lower
cross-correlation with luminous galaxies. Here we forecast the expected
precision of the cross-correlation measurement for current and future GW
detectors such as LIGO and the Einstein Telescope. We then predict how well
these instruments can distinguish the model that identifies high-mass BH-BH
mergers as the merger of primordial black holes that constitute the dark matter
in the Universe from more traditional astrophysical sources.


title: Modelling the cosmic ray electron propagation in M 51

abstract:
  Cosmic ray electrons (CREs) are a crucial part of the ISM and are observed
via synchrotron emission. While much modelling has been carried out on the CRE
distribution and propagation of the Milky Way, little has been done on normal
external star-forming galaxies. Recent spectral data from a new generation of
radio telescopes enable us to find more robust estimations of the CRE
propagation. We model the synchrotron spectral index of M 51 using the
time-dependent diffusion energy-loss equation and to compare the model results
with the observed spectral index determined from recent low-frequency
observations with LOFAR. This is the first time that this model for CRE
propagation has been solved for a realistic distribution of CRE sources, which
we derive from the observed star formation rate, in an external galaxy. The
radial variation of the synchrotron spectral index and scale-length produced by
the model are compared to recent LOFAR and older VLA observational data and
also to new observations of M 51 at 325MHz obtained with the GMRT. We find that
propagation of CREs by diffusion alone is sufficient to reproduce the observed
spectral index distribution in M 51. An isotropic diffusion coefficient with a
value of $6.6\pm0.2\,\times 10^{28}\mathrm{cm}^2\,\mathrm{s}^{-1}$ is found to
fit best and is similar to what is seen in the Milky Way. We estimate an escape
time of $11\,\mathrm{Myr}$ from the central galaxy to $88\,\mathrm{Myr}$ in the
extended disk. It is found that an energy dependence of the diffusion
coefficient is not important for CRE energies in the range
$0.01\,\mathrm{GeV}$--$3\,\mathrm{GeV}$. We are able to reproduce the
dependence of the observed synchrotron scale-lengths on frequency, with $l
\propto \nu^{-1/4}$ in the outer disk and $l \propto \nu^{-1/8}$ in the inner
disk.


title: Universality of Black Hole Quantum Computing

abstract:
  By analyzing the key properties of black holes from the point of view of
quantum information, we derive a model-independent picture of black hole
quantum computing. It has been noticed that this picture exhibits striking
similarities with quantum critical condensates, allowing the use of a common
language to describe quantum computing in both systems. We analyze such quantum
computing by allowing coupling to external modes, under the condition that the
external influence must be soft-enough in order not to offset the basic
properties of the system. We derive model-independent bounds on some crucial
time-scales, such as the times of gate operation, decoherence, maximal
entanglement and total scrambling. We show that for black hole type quantum
computers all these time-scales are of the order of the black hole half-life
time. Furthermore, we construct explicitly a set of Hamiltonians that generates
a universal set of quantum gates for the black hole type computer. We find that
the gates work at maximal energy efficiency. Furthermore, we establish a
fundamental bound on the complexity of quantum circuits encoded on these
systems, and characterize the unitary operations that are implementable. It
becomes apparent that the computational power is very limited due to the fact
that the black hole life-time is of the same order of the gate operation time.
As a consequence, it is impossible to retrieve its information, within the
life-time of a black hole, by externally coupling to the black hole qubits.
However, we show that, in principle, coupling to some of the internal degrees
of freedom allows acquiring knowledge about the micro-state. Still, due to the
trivial complexity of operations that can be performed, there is no time
advantage over the collection of Hawking radiation and subsequent decoding.

categories: hep-th cond-mat.quant-gas gr-qc quant-ph


title:
Neutrinos from type Ia supernovae: the deflagration-to-detonation
  transition scenario

abstract:
  It has long been recognized that the neutrinos detected from the next
core-collapse supernova in the Galaxy have the potential to reveal important
information about the dynamics of the explosion and the nucleosynthesis
conditions as well as allowing us to probe the properties of the neutrino
itself. The neutrinos emitted from thermonuclear - type Ia - supernovae also
possess the same potential, although these supernovae are dimmer neutrino
sources. For the first time, we calculate the time, energy, line of sight, and
neutrino-flavor-dependent features of the neutrino signal expected from a
three-dimensional delayed-detonation explosion simulation, where a
deflagration-to-detonation transition triggers the complete disruption of a
near-Chandrasekhar mass carbon-oxygen white dwarf. We also calculate the
neutrino flavor evolution along eight lines of sight through the simulation as
a function of time and energy using an exact three-flavor transformation code.
We identify a characteristic spectral peak at $\sim 10$ MeV as a signature of
electron captures on copper. This peak is a potentially distinguishing feature
of explosion models since it reflects the nucleosynthesis conditions early in
the explosion. We simulate the event rates in the Super-K, Hyper-K, JUNO, and
DUNE neutrino detectors with the SNOwGLoBES event rate calculation software and
also compute the IceCube signal. Hyper-K will be able to detect neutrinos from
our model out to a distance of $\sim 10$ kpc. At 1 kpc, JUNO, Super-K, and DUNE
would register a few events while IceCube and Hyper-K would register several
tens of events.