title: Metacommutation of Hurwitz primes

abstract:
  Conway and Smith introduced the operation of metacommutation for pairs of
primes in the ring of Hurwitz integers in the quaternions. We study the
permutation induced on the primes of norm p by a prime of norm q under
metacommutation, where p and q are distinct rational primes. In particular, we
show that the sign of this permutation is the quadratic character of q modulo
p.


title: Revisiting the Merit-Order Effect of Renewable Energy Sources

abstract:
  An on-going debate in the energy economics and power market community has
raised the question if energy-only power markets are increasingly failing due
to growing feed-in shares from subsidized renewable energy sources (RES). The
short answer to this is: No, they are not failing. Energy-based power markets
are, however, facing several market distortions, namely from the gap between
the electricity volume traded at day-ahead markets versus the overall
electricity consumption as well as the (wrong) regulatory assumption that
variable RES generation, i.e., wind and photovoltaic (PV), truly have zero
marginal operation costs. In this paper we show that both effects over-amplify
the well-known merit-order effect of RES power feed-in beyond a level that is
explainable by underlying physical realities, i.e., thermal power plants being
willing to accept negative electricity prices to be able to stay online due to
considerations of wear & tear and start-stop constraints. We analyze the
impacts of wind and PV power feed-in on the day-ahead market for a region that
is already today experiencing significant feed-in tariff (FIT)-subsidized RES
power feed-in, the EPEX German-Austrian market zone ($\approx\,$20% FIT share).
Our analysis shows that, if the necessary regulatory adaptations are taken,
i.e., increasing the day-ahead market's share of overall load demand and using
the true marginal costs of RES units in the merit-order, energy-based power
markets can remain functional despite high RES power feed-in.


title: Networked Estimation using Sparsifying Basis Prediction

abstract:
  We present a framework for networked state estimation, where systems encode
their (possibly high dimensional) state vectors using a mutually agreed basis
between the system and the estimator (in a remote monitoring unit). The basis
sparsifies the state vectors, i.e., it represents them using vectors with few
non-zero components, and as a result, the systems might need to transmit only a
fraction of the original information to be able to recover the non-zero
components of the transformed state vector. Hence, the estimator can recover
the state vector of the system from an under-determined linear set of
equations. We use a greedy search algorithm to calculate the sparsifying basis.
Then, we present an upper bound for the estimation error. Finally, we
demonstrate the results on a numerical example.


title:
Compatible almost complex structures on twistor spaces and their
  Gray-Hervella classes

abstract:
  In this paper we determine the Gray-Hervella classes of the compatible almost
complex structures on the twistor spaces of oriented Riemannian four-manifolds
considered by G. Deschamps


title: On the Reality of "Zero Magnetic" Oscillations of Potential

abstract:
  The existence of natural Zero Magnetic (ZM) oscillations of the distributed
electromagnetic oscillating system (Minkowski space-time) is one of logical
consequences of the self-sufficient potential formalism in electromagnetic
theory. A mental experiment confirming the reality of the ZM waves of
electromagnetic potential is proposed. Main characteristics of those waves are
considered. A problem of possibility of application of the ZM waves to
information transmission between spatially distributed objects (i.e., radio
communication) is formulated.


title: Topological surface state in the Kondo Insulator Samarium Hexaboride

abstract:
  Strongly correlated electron systems show many exotic properties such as
unconventional superconductity, quantum criticality, and Kondo insulating
behavior. In addition, the Kondo insulator SmB6 has been predicted
theoretically to be a 3D topological insulator with a metallic surface state.
We report here transport measurements on doped SmB6, which show that ~3%
magnetic and non-magnetic dopants in SmB6 exhibit clearly contrasting behavior,
evidence that the metallic surface state is only destroyed when time reversal
symmetry is broken. We find as well a quantum percolation limit of impurity
concentration which transform the topological insulator into a conventional
band insulator by forming impurity band. Our careful thickness dependence
results show that SmB6 is the first demonstatrated perfect 3D topological
insulator with virtually zero residual bulk conductivity.


title: Arising information regularities in an observer

abstract:
  The approach defines information process from probabilistic observation,
emerging microprocess,qubit, encoding bits, evolving macroprocess, and extends
to Observer information self-organization, cognition, intelligence and
understanding communicating information. Studying information originating in
quantum process focuses not on particle physics but on natural interactive
impulse modeling Bit composing information observer. Information emerges from
Kolmogorov probabilities field when sequences of 1-0 probabilities link Markov
probabilities modeling arising observer. These objective yes-no probabilities
virtually cuts observing entropy hidden in cutting correlation decreasing
Markov process entropy and increasing entropy of cutting impulse running
minimax principle. Merging impulse curves and rotates yes-no conjugated
entropies in microprocess. The entropies entangle within impulse time interval
ending with beginning space. The opposite curvature lowers potential energy
converting entropy to memorized bit. The memorized information binds reversible
microprocess with irreversible information macroprocess. Multiple interacting
Bits self-organize information process encoding causality, logic and
complexity. Trajectory of observation process carries probabilistic and certain
wave function self-building structural macrounits. Macrounits logically
self-organize information networks encoding in triplet code. Multiple IN
enclose observer information cognition and intelligence. Observer cognition
assembles attracting common units in resonances forming IN hierarchy accepting
only units recognizing IN node. Maximal number of accepted triplets measures
the observer information intelligence. Intelligent observer recognizes and
encodes digital images in message transmission enables understanding the
message meaning. Cognitive logic self-controls encoding the intelligence in
double helix code.


title: Portfolio Optimization in R

abstract:
  We consider the problem of finding the efficient frontier associated with the
risk-return portfolio optimization model. We derive the analytical expression
of the efficient frontier for a portfolio of N risky assets, and for the case
when a risk-free asset is added to the model. Also, we provide an R
implementation, and we discuss in detail a numerical example of a portfolio of
several risky common stocks.


title: Insights Into Quantitative Biology: analysis of cellular adaptation

abstract:
  In the last years many powerful techniques have emerged to measure protein
interactions as well as gene expression. Many progresses have been done since
the introduction of these techniques but not toward quantitative analysis of
data. In this paper we show how to study cellular adaptation and how to detect
cellular subpopulations. Moreover we go deeper in analyzing signal transduction
pathways dynamics.


title:
Wigner distribution, nonclassicality and decoherence of generalized and
  reciprocal binomial states

abstract:
  There are quantum states of light that can be expressed as finite
superpositions of Fock states (FSFS). We demonstrate the nonclassicality of an
arbitrary FSFS by means of its phase space distributions such as the Wigner
function and the $Q$-function. The decoherence of the FSFS is studied by
considering the time evolution of its Wigner function in amplitude decay and
phase damping channels. As examples, we determine the nonclassicality and
decoherence of generalized and reciprocal binomial states.


title: 2178 And All That

abstract:
  For integers g >= 3, k >= 2, call a number N a (g,k)-reverse multiple if the
reversal of N in base g is equal to k times N. The numbers 1089 and 2178 are
the two smallest (10,k)-reverse multiples, their reversals being 9801 = 9x1089
and 8712 = 4x2178. In 1992, A. L. Young introduced certain trees in order to
study the problem of finding all (g,k)-reverse multiples. By using modified
versions of her trees, which we call Young graphs, we determine the possible
values of k for bases g = 2 through 100, and then show how to apply the
transfer-matrix method to enumerate the (g,k)-reverse multiples with a given
number of base-g digits. These Young graphs are interesting finite directed
graphs, whose structure is not at all well understood.


title:
Kaehler structures on T*G having as underlying symplectic form the
  standard one

abstract:
  For a connected Lie group G, we show that a complex structure on the total
space TG of the tangent bundle of G that is left invariant and has the property
that each left translation G-orbit is a totally real submanifold is induced
from a smooth immersion of TG into the complexification of G. For G compact and
connected, we then characterize left invariant and biinvariant complex
structures on the total space T*G of the cotangent bundle of G which combine
with the tautological symplectic structure to a Kaehler structure.


title: Two-colour QCD with heavy quarks at finite densities

abstract:
  We extend the density-of-states approach to gauge systems (LLR method) to QCD
at finite temperature and density with heavy quarks. The approach features an
exponential error suppression and yields the Polyakov loop probability
distribution function over a range of more than hundred orders of magnitude.
SU(2) gauge theory is considered in the confinement and the high-temperature
phase, and at finite densities of heavy quarks. In the latter case, a smooth
rise of the density with the chemical potential is observed, and no critical
phenomenon associated with deconfinement due to finite densities is found.


title: Generalized parton distributions from neutrino experiments

abstract:
  The analysis of deeply virtual meson production is extended to
neutrino-production of the pseudo-Goldstone mesons (pions, kaons, eta-mesons)
on nucleons, with the flavor content of the recoil baryon either preserved, or
changed to a hyperon from the same SU(3) octet. We rely on the SU(3) relations
and express all the cross-sections in terms of the proton generalized parton
distributions (GPDs). The corresponding amplitudes are calculated at the
leading twist level and in the leading order in \alpha_{s}, using a
phenomenological parametrization of GPDs. We also included in the analysis the
electromagnetic O(alpha_{em})-corrections to neutrino-induced deeply virtual
meson production (\nuDVMP). We found that such electromagnetic corrections
decrease with Q^2 in the Bjorken regime less than the standard \nuDVMP handbag
contribution, so the electromagnetic mechanism dominates at large Q^2. The
electromagnetic corrections give rise to an angular correlation between the
lepton and hadron scattering planes with harmonics sensitive to the real and
imaginary parts of the DVMP amplitude. These corrections constitute a few
percent effect in the kinematics of the forthcoming MINERvA experiment at
Fermilab and should be taken into account in precise tests of GPD
parametrizations. For virtualities Q^2~100 GeV^2 these corrections become on a
par with \nuDVMP handbag contributions.


title: An exotic proposal on Cooper pairing in high-$T_c$ supercondutors

abstract:
  We propose that a Cooper pair in a high-$T_c$ superconductor might be in fact
a bound system $\rm eex\bar x$ of two electrons, a particle $\rm x$ and its
antiparticle. We assume $\rm eex\bar x$ is more massive than two free
electrons. We observe that $\rm eex\bar x$ should be stable in a solid if it is
in a low enough state in the solid. A solid which admits such a low state for
$\rm eex\bar x$ has some properties which seem closely related to the behavior
of HTS materials. The interaction of the $\rm x$-particle which binds the four
particles into $\rm eex\bar x$ has been discussed. We also discuss the scale of
the mass excess of $\rm eex\bar x$ relative to two free electrons. An
experiment designed to detect a bound system of two electrons with a mass
excess has been proposed.


title: Models of coupled dark matter to dark energy

abstract:
  We present three distinct types of models of dark energy in the form of a
scalar field which is explicitly coupled to dark matter. Our construction draws
from the pull-back formalism for fluids and generalises the fluid action to
involve couplings to the scalar field. We investigate the cosmology of each
class of model both at the background and linearly perturbed level. We choose a
potential for the scalar field and a specific coupling function for each class
of models and we compute the Cosmic Microwave Background and matter power
spectra.


title: Segre embedding and related maps and immersions in differential geometry

abstract:
  Segre embedding was introduced by C. Segre (1863--1924) in his famous 1891
article \cite{segre}. The Segre embedding plays an important roles in algebraic
geometry as well as in differential geometry, mathematical physics, and coding
theory. In this article, we survey main results on Segre embedding in
differential geometry. Moreover, we also present recent differential geometric
results on maps and immersions which are constructed in ways similar to Segre
embedding.


title: On the Problem of Ambiguity of Electromagnetic Potential

abstract:
  In the self-sufficient potential formalism, treating all electromagnetic
phenomena as natural or forced oscillations of some distributed electromagnetic
oscillating system (Minkowski space-time), the electromagnetic potential must
be considered as some relative measure describing deviation of the system from
its "undisturbed" state (when both natural and forced oscillations are absent).
Therefore, there is no ambiguity in the gauge of one: all components of the
potential four-vector are asymptotically verging towards zero while the
distance from all free charges and currents enlarges. Such interpretation turns
the electromagnetic potential into a physically real value.


title:
Particle Spectroscopy of Supersymmetric SU(5) in Light of 125 GeV Higgs
  and Muon g-2 Data

abstract:
  The discovery of the Higgs boson at the Large Hadron Collider (LHC) has a
great impact on the minimal supersymmetric extension of the Standard Model
(MSSM). In the context of the constrained MSSM (CMSSM) and its extension with
non-universal masses for the MSSM Higgs doublets (NUHM2), sparticles with
masses $ > 1$ TeV are necessary to reproduce the observed Higgs boson mass of
125-126 GeV. On the other hand, there appears to be a significant amount of
discrepancy between the measured muon $g-2$ and the Standard Model prediction.
A successful explanation of this discrepancy in the MSSM requires new
contributions involving relatively light sparticles with masses $ < 1$ TeV. In
this paper, we attempt to accommodate the two conflicting requirements in an
SU(5) inspired extension of the CMSSM. We assign non-universal but flavor blind
soft supersymmetry breaking masses to the scalar components in $\bar 5$ and 10
matter supermultiplets. The two MSSM Higgs doublets in the 5, $\bar5$
representations of SU(5) are also assigned unequal soft mass$^2$ at $M_{GUT}$.
We identify parameter regions which can simultaneously accommodate the observed
Higgs boson mass and the muon $g-2$ data, and which are compatible with other
phenomenological constraints such as neutralino dark matter relic abundance and
rare B-meson decays. Some regions of the allowed parameter space will be
explored at the upgraded LHC and by dark matter direct detection experiments.


title: Relative velocities of inertial particles in turbulent aerosols

abstract:
  We compute the joint distribution of relative velocities and separations of
identical inertial particles suspended in randomly mixing and turbulent flows.
Our results are obtained by matching asymptotic forms of the distribution. The
method takes into account spatial clustering of the suspended particles as well
as singularities in their motion (so-called 'caustics'). It thus takes proper
account of the fractal properties of phase space and the distribution is
characterised in terms of the corresponding phase-space fractal dimension D_2.
The method clearly exhibits universal aspects of the distribution (independent
of the statistical properties of the flow): at small particle separations R and
not too large radial relative speeds |V_R|, the distribution of radial relative
velocities exhibits a universal power-law form \rho(V_R,R) \sim |V_R|^{D_2-d-1}
provided that D_2 < d+1 (d is the spatial dimension) and that the Stokes number
St is large enough for caustics to form. The range in V_R over which this power
law is valid depends on R, on the Stokes number, and upon the nature of the
flow. Our results are in good agreement with results of computer simulations of
the dynamics of particles suspended in random velocity fields with finite
correlation times. In the white-noise limit the results are consistent with
those of [Gustavsson and Mehlig, Phys. Rev. E84 (2011) 045304].


title:
ALMA and CARMA observations of Brown Dwarfs disks: testing the models of
  dust evolution

abstract:
  The first steps toward planet formation involve the coagulation of small
microscopic grains into larger and larger pebbles and rocks in gas-rich disks
around young stars and brown dwarfs. Observations in the sub-millimeter can
trace mm/cm-sized pebbles in the outer disks, and investigate the mechanisms of
coagulation/fragmentation and radial migration of these solids. These represent
key, yet not fully understood ingredients for our understanding of the
formation of planetesimals, the building blocks of planets. Here we present the
first results from an observational program using the ALMA and CARMA sub-mm/mm
interferometers aimed at characterizing the dust properties and disk structure
of young disks around brown dwarfs and very low mass stars. Given the physical
conditions expected for these disks, they represent critical test beds for the
models of the early stages of planet formation in proto-planetary disks.


title: Bunches of Random Cross-correlated Sequences

abstract:
  Statistical properties of random cross-correlated sequences constructed by
the convolution method (likewise referred to as the Rice's or the inverse
Fourier transformation) are examined. Algorithms for their generation are
discussed. They are frequently reduced to solving the problem for decomposition
of the Fourier transform of the correlation matrix into a product of two
mutually conjugate matrices; different decompositions of the correlation matrix
are considered. The limits of weak and strong correlations for the one-point
probability and pair correlation functions of the sequences are studied.
Special cases of heavy-tailed distributions resulting from the convolution
generation are analyzed. Anisotropic properties of statistically homogeneous
random sequences related to asymmetry of a filtering function are discussed.


title: Representability Conditions by Grassmann Integration

abstract:
  Representability conditions on the one- and two-particle density matrix for
fermion systems are formulated by means of Grassmann integrals. A positivity
condition for a certain kind of Grassmann integral is established which, in
turn, induces the well-known G-, P- and Q-Conditions of quantum chemistry by an
appropriate choice of the integrand. Similarly, the T1- and T2-Conditions are
derived. Furthermore, quasifree Grassmann states are introduced and it is shown
that every so-called generalized one-particle density matrix which is bounded
between 0 and 1 corresponds to a unique quasifree Grassmann state.


title: Unoriented Quivers with Flavour

abstract:
  We discuss unoriented quivers with flavour that arise from D3-branes at local
orbifold singularities, in the presence of Omega-planes and non-compact
D7-branes. We produce a wide class of unoriented quiver gauge theories,
including new instances of N=1 superconformal theories. We then consider
unoriented D-brane instanton corrections of both `gauge' and `exotic' kinds. In
particular, we show that conformal symmetry can be dynamically broken via the
generation of exotic superpotentials. Finally we discuss aspects of the
recently proposed N=1 remnant of N=4 S-duality. We identify new candidate dual
pairs for the C^3/Z_n series of unoriented quiver gauge theories with n odd.


title: Reduction of cluster iteration maps to symplectic maps

abstract:
  We study iteration maps of recurrence relations arising from mutation
periodic quivers of arbitrary period. Combining tools from cluster algebra
theory and (pre)symplectic geometry, we show that these cluster iteration maps
can be reduced to symplectic maps on a lower dimensional submanifold, provided
the matrix representing the quiver is singular. The reduced iteration map is
explicitly computed for several new periodic quivers.


title: Discrete Signal Processing on Graphs: Frequency Analysis

abstract:
  Signals and datasets that arise in physical and engineering applications, as
well as social, genetics, biomolecular, and many other domains, are becoming
increasingly larger and more complex. In contrast to traditional time and image
signals, data in these domains are supported by arbitrary graphs. Signal
processing on graphs extends concepts and techniques from traditional signal
processing to data indexed by generic graphs. This paper studies the concepts
of low and high frequencies on graphs, and low-, high-, and band-pass graph
filters. In traditional signal processing, there concepts are easily defined
because of a natural frequency ordering that has a physical interpretation. For
signals residing on graphs, in general, there is no obvious frequency ordering.
We propose a definition of total variation for graph signals that naturally
leads to a frequency ordering on graphs and defines low-, high-, and band-pass
graph signals and filters. We study the design of graph filters with specified
frequency response, and illustrate our approach with applications to sensor
malfunction detection and data classification.


title: Rectifiers and the local Langlands correspondence: the unramified case

abstract:
  We generalize the rectifier of Bushnell and Henniart, which occurs in the
local Langlands correspondence for $GL_n(K)$, to certain Langlands parameters
for unramified connected reductive groups.


title:
Estimation of Phase and Diffusion: Combining Quantum Statistics and
  Classical Noise

abstract:
  Coherent ensembles of $N$ qubits present an advantage in quantum phase
estimation over separable mixtures, but coherence decay due to classical phase
diffusion reduces overall precision. In some contexts, the strength of
diffusion may be the parameter of interest. We examine estimation of both phase
and diffusion in large spin systems using a novel mathematical formulation. For
the first time, we show a closed form expression for the quantum Fisher
information for estimation of a unitary parameter in a noisy environment. The
optimal probe state has a non-Gaussian profile and differs also from the
canonical phase state; it saturates a new tight precision bound. For noise
below a critical threshold, entanglement always leads to enhanced precision,
but the shot-noise limit is beaten only by a constant factor, independent of
$N$. We provide upper and lower bounds to this factor, valid in low and high
noise regimes. Unlike other noise types, it is shown for $N \gg 1$ that phase
and diffusion can be measured simultaneously and optimally.

categories: quant-ph math.ST physics.ins-det physics.optics stat.TH


title: Quantum support vector machine for big data classification

abstract:
  Supervised machine learning is the classification of new data based on
already classified training examples. In this work, we show that the support
vector machine, an optimized binary classifier, can be implemented on a quantum
computer, with complexity logarithmic in the size of the vectors and the number
of training examples. In cases when classical sampling algorithms require
polynomial time, an exponential speed-up is obtained. At the core of this
quantum big data algorithm is a non-sparse matrix exponentiation technique for
efficiently performing a matrix inversion of the training data inner-product
(kernel) matrix.


title: Metal-Rich PNe in the Outer Reaches of M31

abstract:
  Spectroscopic data of two relatively [O III]-luminous-PNe have been obtained
with the 10.4-m Gran Telescopio Canarias. M174 and M2496 are each ~1 degree
from the center of M31 along opposite sides of its minor axis. The ensemble of
these two distant PNe plus 16 similarly luminous outer-disk PNe published
earlier (Kwitter et al. 2012 & 2013) forms a homogeneous group in luminosity,
metal content, progenitor mass, age, and kinematics. The main factual findings
of our work are: (1) O/H (and other low-mass alpha elements and their ratios to
O) is uniformly solar-like in all 18 PNe <12+log(O/H)> = 8.62 +/- 0.14); (2)
the general sky distribution and kinematics of the ensemble much more closely
resemble the rotation pattern of the classical disk of M31 than its halo or
bulge; (3) the O/H gradient is surprisingly flat beyond R_g ~30 kpc, and may be
flat throughout the entire range of R_g covered in the full study. The PNe are
too metal-rich to be bona fide members of M31's disk or halo, and (4) the
abundance patterns of the sample are distinct from those in the spiral galaxies
M33, M81, and NGC 300. Using standard PN age diagnostic methods (which are
readily challengeable) we suggest that all of the PNe formed -2 GY ago in a
starburst of metal-rich ISM that followed an M31-M33 encounter about 3 GY ago.
We review supporting evidence from stellar studies. Other more prosaic
explanations, such as dwarf galaxy assimilation, are unlikely.


title:
Online discrete optimization in social networks in the presence of
  Knightian uncertainty

abstract:
  We study a model of collective real-time decision-making (or learning) in a
social network operating in an uncertain environment, for which no a priori
probabilistic model is available. Instead, the environment's impact on the
agents in the network is seen through a sequence of cost functions, revealed to
the agents in a causal manner only after all the relevant actions are taken.
There are two kinds of costs: individual costs incurred by each agent and
local-interaction costs incurred by each agent and its neighbors in the social
network. Moreover, agents have inertia: each agent has a default mixed strategy
that stays fixed regardless of the state of the environment, and must expend
effort to deviate from this strategy in order to respond to cost signals coming
from the environment. We construct a decentralized strategy, wherein each agent
selects its action based only on the costs directly affecting it and on the
decisions made by its neighbors in the network. In this setting, we quantify
social learning in terms of regret, which is given by the difference between
the realized network performance over a given time horizon and the best
performance that could have been achieved in hindsight by a fictitious
centralized entity with full knowledge of the environment's evolution. We show
that our strategy achieves the regret that scales polylogarithmically with the
time horizon and polynomially with the number of agents and the maximum number
of neighbors of any agent in the social network.


title:
A signature-based search for delayed photons in exclusive photon plus
  missing transverse energy events from $p \bar{p}$ collisions with $\sqrt{s} =
  1.96$ TeV

abstract:
  We present the first signature-based search for delayed photons using an
exclusive photon plus missing transverse energy final state. Events are
reconstructed in a data sample from the CDF II detector corresponding to $6.3
\text{fb}^{-1}$ of integrated luminosity from $\sqrt{s}=1.96$ TeV
proton-antiproton collisions. Candidate events are selected if they contain a
photon with an arrival time in the detector larger than expected from a
promptly-produced photon. The mean number of events from standard model sources
predicted by the data-driven background model based on the photon timing
distribution is $286 \pm 24$. A total of 322 events are observed. A $p$-value
of 12% is obtained, showing consistency of the data with standard model
predictions.


title:
A Random Matrix Approach to Differential Privacy and Structure Preserved
  Social Network Graph Publishing

abstract:
  Online social networks are being increasingly used for analyzing various
societal phenomena such as epidemiology, information dissemination, marketing
and sentiment flow. Popular analysis techniques such as clustering and
influential node analysis, require the computation of eigenvectors of the real
graph's adjacency matrix. Recent de-anonymization attacks on Netflix and AOL
datasets show that an open access to such graphs pose privacy threats. Among
the various privacy preserving models, Differential privacy provides the
strongest privacy guarantees.
  In this paper we propose a privacy preserving mechanism for publishing social
network graph data, which satisfies differential privacy guarantees by
utilizing a combination of theory of random matrix and that of differential
privacy. The key idea is to project each row of an adjacency matrix to a low
dimensional space using the random projection approach and then perturb the
projected matrix with random noise. We show that as compared to existing
approaches for differential private approximation of eigenvectors, our approach
is computationally efficient, preserves the utility and satisfies differential
privacy. We evaluate our approach on social network graphs of Facebook, Live
Journal and Pokec. The results show that even for high values of noise variance
sigma=1 the clustering quality given by normalized mutual information gain is
as low as 0.74. For influential node discovery, the propose approach is able to
correctly recover 80 of the most influential nodes. We also compare our results
with an approach presented in [43], which directly perturbs the eigenvector of
the original data by a Laplacian noise. The results show that this approach
requires a large random perturbation in order to preserve the differential
privacy, which leads to a poor estimation of eigenvectors for large social
networks.


title: Shear and bulk viscosities of a photon gas at low temperature

abstract:
  We explore the viscosities of a photon gas by means of the Euler-Heisenberg
effective theory and quantum electrodynamics at zero electron chemical
potential. We find parametric estimates that show a very large shear viscosity
and an extremely small bulk viscosity (reflecting the very weak coupling
simultaneously with a very approximate dilatation invariance). The system is of
some interest because it exemplifies very neatly the influence of the breaking
of scale invariance on the bulk viscosity.


title: Monotonicity Formulas for Bakry-Emery Ricci Curvature

abstract:
  Motivated and inspired by the recent work of Colding [5] and
Colding-Minicozzi [6] we derive several families of monotonicity formulas for
manifolds with nonnegative Bakry-Emery Ricci curvature, extending the formulas
in [5, 6].


title: The Bases of Effective Field Theories

abstract:
  With reference to the equivalence theorem, we discuss the selection of basis
operators for effective field theories in general. The equivalence relation can
be used to partition operators into equivalence classes, from which
inequivalent basis operators are selected. These classes can also be identified
as containing Potential-Tree-Generated (PTG) operators, Loop-Generated (LG)
operators, or both, independently of the specific dynamics of the underlying
extended models, so long as it is perturbatively decoupling. For an equivalence
class containing both, we argue that the basis operator should be chosen from
among the PTG operators, because they may have the largest coefficients. We
apply this classification scheme to dimension-six operators in an illustrative
Yukawa model as well in the Standard Model (SM). We show that the basis chosen
by Grzadkowski {\it et. al.} \cite{Grzadkowski:2010es} for the SM satisfies
this criterion. In this light, we also revisit and verify our earlier result
\cite{Arzt:1994gp} that the dimension-six corrections to the triple-gauge-boson
couplings only arise from LG operators, so the magnitude of the coefficients
should only be a few parts per thousand of the SM gauge coupling if BSM
dynamics respects decoupling. The same is true of the quartic-gauge-boson
couplings.


title: Uncertainty principle in a cavity at finite temperature

abstract:
  We employ a dressed state approach to perform a study on the behavior of the
uncertainty principle for a system in a heated cavity. We find, in a small
cavity for a given temperature, an oscillatory behavior of the
momentum--coordinate product, $(\Delta\,p)\,(\Delta\,q)$, which attains
periodically finite absolute minimum (maximum) values, no matter large is the
elapsed time. This behavior is in a sharp contrast with what happens in free
space, in which case, the product $(\Delta\,p)\,(\Delta\,q)$ tends
asymptotically, for each temperature, to a constant value, independent of time.


title: $T_7$ Flavor Model in Three Loop Seesaw and Higgs Phenomenology

abstract:
  We propose a new type of radiative seesaw model in which observed neutrino
masses are generated through a three-loop level diagram in combination with
tree-level type-II seesaw mechanism in a renormalizable theory. We introduce a
Non-abelian flavor symmetry $T_7$ in order to constrain the form of Yukawa
interactions and Higgs potential. Although several models based on a
Non-abelian flavor symmetry predict the universal coupling constants among the
standard model like Higgs boson and charged leptons, which is disfavored by the
current LHC data, our model can avoid such a situation. We show a benchmark
parameter set that is consistent with the current experimental data, and we
discuss multi-muon events as a key collider signature to probe our model.


title:
Baker-Akhiezer spinor kernel and tau-functions on moduli spaces of
  meromorphic differentials

abstract:
  In this paper we study Baker-Akhiezer spinor kernel on moduli spaces of
meromorphic differentials on Riemann surfaces. We introduce the Baker-Akhiezer
tau-function which is related to both Bergman tau-function (which was studied
before in the context of Hurwitz spaces and spaces of holomorphic and quadratic
differentials) and KP tau-function on such spaces. In particular, we derive
variational formulas of Rauch-Ahlfors type on moduli spaces of meromorphic
differentials with prescribed singularities: we use the system of homological
coordinates, consisting of absolute and relative periods of the meromorphic
differential, and show how to vary the fundamental objects associated to a
Riemann surface (the matrix of $b$-periods, normalized Abelian differentials,
the Bergman bidifferential, the Szeg\"o kernel and the Baker-Akhiezer spinor
kernel) with respect to these coordinates. The variational formulas encode
dependence both on the moduli of the Riemann surface and on the choice of
meromorphic differential (variation of the meromorphic differential while
keeping the Riemann surface fixed corresponds to flows of KP type). Analyzing
the global properties of the Bergman and Baker-Akhiezer tau-functions we
establish relationships between various divisor classes on the moduli spaces.


title: "Vacuum-like" Hadamard states for quantum fields on curved spacetimes

abstract:
  We present a modification of the recently proposed Sorkin-Johnston states for
scalar free quantum fields on a class of globally hyperbolic spacetimes
possessing compact Cauchy hypersurfaces. The modification relies on a smooth
cutoff of the commutator function and leads always to Hadamard states, in
contrast to the original Sorkin-Johnston states. The modified Sorkin-Johnston
states are, however, due to the smoothing no longer uniquely associated to the
spacetime.


title:
A Compressive Sampling Approach To Adaptive Multi-Resolution
  Approximation of Differential Equations With Random Inputs

abstract:
  In this paper, a novel method to adaptively approximate the solution to
stochastic differential equations, which is based on compressive sampling and
sparse recovery, is introduced. The proposed method consider the problem of
sparse recovery with respect to multi-wavelet basis (MWB) from a small number
of random samples to approximate the solution to problems. To illustrate the
robustness of developed method, three benchmark problems are studied and main
statistical features of solutions such as the variance and the mean of
solutions obtained by proposed method are compared with the ones obtained from
Monte Carlo simulations.


title: The dilaton Wess-Zumino action in higher dimensions

abstract:
  We present a general formula for the Wess-Zumino action associated with the
Weyl anomaly, given in a curved background for any even number of dimensions.
The result is obtained by considering a finite Weyl transformation of
counterterms in dimensional regularization.


title:
Berezinskii-Kosterlitz-Thouless Transition with a Constraint Lattice
  Action

abstract:
  The 2d XY model exhibits an essential phase transition, which was predicted
long ago --- by Berezinskii, Kosterlitz and Thouless (BKT) --- to be driven by
the (un)binding of vortex--anti-vortex pairs. This transition has been
confirmed for the standard lattice action, and for actions with distinct
couplings, in agreement with universality. Here we study a highly
unconventional formulation of this model, which belongs to the class of
topological lattice actions: it does not have any couplings at all, but just a
constraint for the relative angles between nearest neighbour spins. By means of
dynamical boundary conditions we measure the helicity modulus Upsilon, which
shows that this formulation performs a BKT phase transition as well. Its finite
size effects are amazingly mild, in contrast to other lattice actions. This
provides one of the most precise numerical confirmations ever of a BKT
transition in this model. On the other hand, up to the lattice sizes that we
explored, there are deviations from the spin wave approximation, for instance
for the Binder cumulant U_4 and for the leading finite size correction to
Upsilon. Finally we observe that the (un)binding mechanism follows the usual
pattern, although free vortices do not require any energy in this formulation.
Due to that observation, one should reconsider an aspect of the established
picture, which estimates the critical temperature based on this energy
requirement.


title: Examples of CM curves of genus two defined over the reflex field

abstract:
  In "Proving that a genus 2 curve has complex multiplication", van Wamelen
lists 19 curves of genus two over $\mathbf{Q}$ with complex multiplication
(CM). For each of the 19 curves, the CM-field turns out to be cyclic Galois
over $\mathbf{Q}$. The generic case of non-Galois quartic CM-fields did not
feature in this list, as the field of definition in that case always contains a
real quadratic field, known as the real quadratic subfield of the reflex field.
  We extend van Wamelen's list to include curves of genus two defined over this
real quadratic field. Our list therefore contains the smallest "generic"
examples of CM curves of genus two.
  We explain our methods for obtaining this list, including a new
height-reduction algorithm for arbitrary hyperelliptic curves over totally real
number fields. Unlike Van Wamelen, we also give a proof of our list, which is
made possible by our implementation of denominator bounds of Lauter and Viray
for Igusa class polynomials.


title: Topology of quadrature domains

abstract:
  We address the problem of topology of quadrature domains, namely we give
upper bounds on the connectivity of the domain in terms of the number of nodes
and their multiplicities in the quadrature identity.


title: Two-component Bose gases with one-body and two-body couplings

abstract:
  We study the competition between one-body and two-body couplings in
weakly-interacting two-component Bose gases, in particular as regards field
correlations. We derive the meanfield theory for both ground state and
low-energy pair excitations in the general case where both one-body and
two-body couplings are position-dependent and the fluid is subjected to a
state-dependent trapping potential. General formulas for phase and density
correlations are also derived. Focusing on the case of homogeneous systems, we
discuss the pair-excitation spectrum and the corresponding excitation modes,
and use them to calculate correlation functions, including both quantum and
thermal fluctuation terms. We show that the relative phase of the two
components is imposed by that of the one-body coupling, while its fluctuations
are determined by the modulus of the one-body coupling and by the two-body
coupling. One-body coupling and repulsive two-body coupling cooperate to
suppress relative-phase fluctuations, while attractive two-body coupling tends
to enhance them. Further applications of the formalism presented here and
extensions of our work are also discussed.


title: Scalability using effects

abstract:
  This note is about using computational effects for scalability. With this
method, the specification gets more and more complex while its semantics gets
more and more correct. We show, from two fundamental examples, that it is
possible to design a deduction system for a specification involving an effect
without expliciting this effect.


title: The small noise limit of order-based diffusion processes

abstract:
  We introduce order-based diffusion processes as the solutions to
multidimensional stochastic differential equations, with drift coefficient
depending only on the ordering of the coordinates of the process and diffusion
matrix proportional to the identity. These processes describe the evolution of
a system of Brownian particles moving on the real line with piecewise constant
drifts, and are the natural generalization of the rank-based diffusion
processes introduced in stochastic portfolio theory or in the probabilistic
interpretation of nonlinear evolution equations. Owing to the discontinuity of
the drift coefficient, the corresponding ordinary differential equations are
ill-posed. Therefore, the small noise limit of order-based diffusion processes
is not covered by the classical Freidlin-Wentzell theory. The description of
this limit is the purpose of this article. We first give a complete analysis of
the two-particle case. Despite its apparent simplicity, the small noise limit
of such a system already exhibits various behaviours. In particular, depending
on the drift coefficient, the particles can either stick into a cluster, the
velocity of which is determined by elementary computations, or drift away from
each other at constant velocity, in a random ordering. The persistence of
randomness in the zero noise limit is of the very same nature as in the
pioneering works by Veretennikov (Mat. Zametki, 1983) and Bafico and Baldi
(Stochastics, 1981) concerning the so-called Peano phenomenon. In the case of
rank-based processes, we use a simple convexity argument to prove that the
small noise limit is described by the sticky particle dynamics introduced by
Brenier and Grenier (SIAM J. Numer. Anal., 1998), where particles travel at
constant velocity between collisions, at which they stick together. In the
general case of order-based processes, we give a sufficient condition on the
drift for all the particles to aggregate into a single cluster, and compute the
velocity of this cluster. Our argument consists in turning the study of the
small noise limit into the study of the long time behaviour of a suitably
rescaled process, and then exhibiting a Lyapunov functional for this rescaled
process.


title:
Parallelization of a relaxation scheme modelling the bedload transport
  of sediments in shallow water flow

abstract:
  In this work we are interested in numerical simulations for bedload erosion
processes. We present a relaxation solver that we apply to moving dunes test
cases in one and two dimensions. In particular we retrieve the so-called
anti-dune process that is well described in the experiments. In order to be
able to run 2D test cases with reasonable CPU time, we also describe and apply
a parallelization procedure by using domain decomposition based on the
classical MPI library.


title:
Ver\"anderungen \"uber einen Satz von Timmesfeld - II. Symmetric powers
  of Nat sl(2,K)

abstract:
  We identify the spaces of homogeneous polynomials in two variables K[Y^k,
XY^{k-1}, ..., X^k] among representations of the Lie ring sl(2,K). This amounts
to constructing a compatible K-linear structure on some abstract
sl(2,K)-modules, where sl(2,K) is viewed as a Lie ring.


title:
The exponential map of the complexification of {\em Ham} in the
  real-analytic case

abstract:
  Let $(M, \omega, J)$ be a K\"ahler manifold and K its group of hamiltonian
symplectomorphisms. The complexification of K introduced by Donadson is not a
group, only a "formal Lie group". However it still makes sense to talk about
the exponential map in the complexification. In this note we show how to
construct geometrically the exponential map (for small time), in case the
initial data are real-analytic. The construction is motivated by, but does not
use, semiclassical analysis.


title:
Prolonged spontaneous emission and dephasing of localized excitons in
  air-bridged carbon nanotubes

abstract:
  The bright exciton emission of semiconducting carbon nanotubes is appealing
for optoelectronic and quantum photonic devices as well as fundamental studies
of light-matter interaction in one-dimensional nanostructures. The photophysics
of excitons in carbon nanotubes till date is however largely affected by
extrinsic effects of the dielectric environment. Here we carried out
time-resolved photoluminescence measurements over 14 orders of magnitude for
ultra-clean carbon nanotubes bridging an airgap over pillar posts. Our
measurements demonstrate a new regime of intrinsic exciton photophysics with
prolonged spontaneous emission times up to T1=18 ns, between one to two orders
of magnitude better than prior measurements and in agreement with values first
hypothesized by theorists about a decade ago. Further we establish for the
first time the exciton decoherence times of individual nanotubes in the
time-domain and found four-fold prolonged values up to T2=2.1 ps compared to
ensemble measurements. These first observations motivate new discussions about
the magnitude of the intrinsic dephasing mechanism while the prolonged exciton
dynamics is promising for device applications.


title: Pattern avoidance in ordered set partitions and words

abstract:
  We consider the enumeration of ordered set partitions avoiding a permutation
pattern, as introduced by Godbole, Goyt, Herdan and Pudwell. Let $\op_{n,k}(p)$
be the number of ordered set partitions of $\{1,2,\ldots,n\}$ into $k$ blocks
that avoid a permutation pattern $p$. We establish an explicit identity between
the number $\op_{n,k}(p)$ and the numbers of words avoiding the inverse of $p$.
This identity allows us to easily translate results on pattern-avoiding words
obtained in earlier works into equivalent results on pattern-avoiding ordered
set partitions. In particular, \emph{(a)} we determine the asymptotic growth
rate of the sequence $(\op_{n,k}(p))_{n\geq 1}$ for every positive $k$ and
every permutation pattern $p$, \emph{(b)} we partially confirm a conjecture of
Godbole et al. concerning the variation of the sequences $(\op_{n,k}p))_{1\leq
k\leq n}$, \emph{(c)} we undertake a detailed study of the number of ordered
set partitions avoiding a pattern of length 3.


title: Precision Higgs Measurements: Constraints from New Oblique Corrections

abstract:
  New particles entering into self-energies of the Higgs boson would
necessarily modify loop-induced couplings of the Higgs, if the new particle
carries standard model gauge quantum numbers. For a 1 TeV new particle,
deviations in these "Higgs oblique corrections" are generically of the order of
v^2/(1 TeV)^2 ~ 5%. We study constraints on masses and couplings of new scalars
and fermions that can be derived from 5-10% deviations in the Higgs digluon and
diphoton partial widths. To reduce theoretical uncertainties, we present
next-to-leading order QCD corrections to the Higgs-to-digluon coupling for
scalars and fermions in arbitrary representations of SU(3) color group, by
applying the low-energy Higgs theorems at two-loop order. As a by-product we
provide a new value for NLO QCD corrections to the top squark contributions to
digluon decays that differs from existing literature. We also emphasize that
precise measurements of Higgs couplings to W boson and top quark are
prerequisite to precise determinations of Higgs oblique corrections from new
particles.


title:
Determining the Spectrum of Cosmic Rays in Interstellar Space from the
  Diffuse Galactic Gamma-Ray Emissivity

abstract:
  More than 90% of the Galactic gas-related gamma-ray emissivity above 1 GeV is
attributed to the decay of neutral pions formed in collisions between cosmic
rays and interstellar matter, with lepton-induced processes becoming
increasingly important below 1 GeV. Given the high-quality measurements of the
gamma-ray emissivity of local interstellar gas between ~50 MeV and ~4 GeV
obtained with the Large Area Telescope on board the Fermi space observatory, it
is timely to re-investigate this topic in detail, including the hadronic
production mechanisms. The emissivity spectrum will allow the interstellar
cosmic-ray spectrum to be determined reliably, providing a reference for origin
and propagation studies as well as input to solar modulation models. A method
for such an analysis and illustrative results are presented.


title: Categorification of Lie algebras [d'apres Rouquier, Khovanov-Lauda]

abstract:
  Given a vector space with an action of a semi-simple Lie algebra, we can try
to "categorify" this representation, which means finding a category where the
generators of the Lie algebra act by functors. Such categorical representations
arise naturally in geometric representation theory and in modular
representation theory of symmetric groups. A framework for studying categorical
representations was introduced by Rouquier and Khovanov-Lauda. Their
definitions are algebraic/diagrammatic, but are connected to the topology of
quiver varieties by the work of Rouquier and Varagnolo-Vasserot. In this paper,
we give a survey of the above circle of ideas.


title: Physical Determination of the Action

abstract:
  The objective is a foundation of physics from the operationalization of its
basic observables. We begin with classical and relativistic kinematics. Seizing
on a programmatic proposal by Heinrich Hertz we arrive via quantification of
energy-momentum at the equations of motion and the action functional. Finally
we present a relativistic revision of energy, momentum and inertial mass. The
goal is not primarily to change or improve the mathematical structure of
mechanics, but to gain a deeper physical understanding of mechanics like
Einstein with his gedanken experiments on relativistic kinematics. Starting
from undisputed measurement operations and natural principles the mathematical
formalism is only created and thus shown in a new light. This work is in the
same context as current efforts to the "foundation of quantum mechanics", just
with respect to the interpretation of the classical and relativistic
calculuses.


title: Plasticity and non-Schmid effects

abstract:
  The structure of the overall response of a metal polycrystal is analyzed
under the assumption that activity on the slip systems of its constituents is
governed by a generalized Schmid law. In the resulting macro-model of metal
plasticity the overall rate of plastic deformation is related to the
stress-gradient of the yield surface via a generalized, but still associated
flow rule. While the overall rate of plastic deformation is no longer collinear
with the stress-gradient of the yield surface, its deviation is characterized
by an additional macro-variable, representative of the rate of the non-Schmid
effects taking place at constituent level.


title:
Possibility of Deconfined Criticality in SU(N) Heisenberg Models at
  Small N

abstract:
  To examine the validity of the scenario of the deconfined critical phenomena,
we carry out a quantum Monte Carlo simulation for the SU($N$) generalization of
the Heisenberg model with four-body and six-body interactions. The quantum
phase transition between the SU($N$) N\'eel and valence-bond solid phases is
characterized for $N=2,3,$ and $4$ on the square and honeycomb lattices. While
finite-size scaling analysis works well up to the maximum lattice size
($L=256$) and indicates the continuous nature of the phase transition, a clear
systematic change towards the first-order transition is observed in the
estimates of the critical exponent $y \equiv 1/\nu$ as the system size
increases. We also confirm the relevance of a squared valence-bond solid field
$\Psi^2$ for the SU(3) model.


title: The prevalence of AGN feedback in massive galaxies at z~1

abstract:
  We use the optical--infrared imaging in the UKIDSS Ultra Deep Survey field,
in combination with the new deep radio map of Arumugam et al., to calculate the
distribution of radio luminosities among galaxies as a function of stellar mass
in two redshift bins across the interval 0.4<z<1.2. This is done with the use
of a new Bayesian method to classify stars and galaxies in surveys with
multi-band photometry, and to derive photometric redshifts and stellar masses
for those galaxies. We compare the distribution to that observed locally and
find agreement if we consider only objects believed to be weak-lined radio-loud
galaxies. Since the local distribution is believed to be the result of an
energy balance between radiative cooling of the gaseous halo and mechanical AGN
heating, we infer that this balance was also present as long ago as z~1. This
supports the existence of a direct link between the presence of a
low-luminosity ('hot-mode') radio-loud active galactic nucleus and the absence
of ongoing star formation.


title: The Physical Squeezed Limit: Consistency Relations at Order q^2

abstract:
  In single-field models of inflation the effect of a long mode with momentum q
reduces to a diffeomorphism at zeroth and first order in q. This gives the
well-known consistency relations for the n-point functions. At order q^2 the
long mode has a physical effect on the short ones, since it induces curvature,
and we expect that this effect is the same as being in a curved FRW universe.
In this paper we verify this intuition in various examples of the three-point
function, whose behaviour at order q^2 can be written in terms of the power
spectrum in a curved universe. This gives a simple alternative understanding of
the level of non-Gaussianity in single-field models. Non-Gaussianity is always
parametrically enhanced when modes freeze at a physical scale k_{ph, f} shorter
than H: f_{NL} \sim (k_{ph, f}/H)^2.


title: Electroelasticity of Charged Black Branes

abstract:
  We present the first-order corrected dynamics of fluid branes carrying
higher-form charge by obtaining the general form of their equations of motion
to pole-dipole order. Assuming linear response theory, we characterize the
corresponding effective theory of stationary bent charged (an)isotropic fluid
branes in terms of two sets of response coefficients, the Young modulus and the
piezoelectric moduli. We subsequently find large classes of examples in gravity
of this effective theory, by constructing stationary strained charged black
brane solutions to first order in a derivative expansion. Using solution
generating techniques and bent neutral black branes as a seed solution, we
obtain a class of charged black brane geometries carrying smeared Maxwell
charge in Einstein-Maxwell-dilaton gravity. In the specific case of
ten-dimensional space-time we furthermore use T-duality to generate bent black
branes with higher-form charge, including smeared D-branes of type II string
theory. By subsequently measuring the bending moment and the electric dipole
moment which these geometries acquire due to the strain, we uncover that their
form is captured by classical electroelasticity theory. In particular, we find
that the Young modulus and the piezoelectric moduli of our strained charged
black brane solutions are parameterized by a total of 4 response coefficients,
both for the isotropic as well as anisotropic cases.


title:
Chemical Abundance Evidence of Enduring High Star Formation Rates in an
  Early Type Galaxy: High [Ca/Fe] in NGC 5128 Globular Clusters

abstract:
  We present [Fe/H], ages, and Ca abundances for an initial sample of 10
globular clusters in NGC 5128 obtained from high resolution, high
signal-to-noise ratio echelle spectra of their integrated light. All abundances
and ages are obtained using our original technique for high resolution
integrated light abundance analysis of globular clusters. The clusters have a
range in [Fe/H] between -1.6 to -0.2. In this sample, the average [Ca/Fe] for
clusters with [Fe/H]<-0.4 is +0.37$\pm$0.07, while the average [Ca/Fe] in our
MW and M31 GC samples is +0.29 $\pm$0.09 and +0.24 $\pm$0.10, respectively.
This may imply a more rapid chemical enrichment history for NGC 5128 than for
either the Milky Way or M31.This sample provides the first quantitative picture
of the chemical history of NGC 5128 that is directly comparable to what is
available for the Milky Way. Data presented here were obtained with the MIKE
echelle spectrograph on the Magellan Clay Telescope.


title:
A Pan-STARRS + UKIDSS Search for Young, Wide Planetary-Mass Companions
  in Upper Scorpius

abstract:
  We have combined optical and NIR photometry from Pan-STARRS 1 and UKIDSS to
search the young (5-10 Myr) star-forming region of Upper Scorpius for wide
(~400-4000 AU) substellar companions down to ~5 Mjup. Our search is ~4mag
deeper than previous work based on 2MASS. We identified several candidates
around known stellar members using a combination of color selection and
spectral energy distribution fitting. Our followup spectroscopy has identified
two new companions as well as confirmed two companions previously identified
from photometry, with spectral types of M7.5-M9 and masses of ~15-60 Mjup,
indicating a frequency for such wide substellar companions of ~0.6+/-0.3%. Both
USco1610-1913B and USco1612-1800B are more luminous than expected for their
spectral type compared with known members of Upper Sco. HIP77900B has an
extreme mass ratio (M2/M1~0.005) and an extreme separation of 3200 AU.
USco1602-2401B also has a very large separation of 1000 AU. We have also
confirmed a low-mass stellar companion, USco1610-2502B (730AU, M5.5). Our
substellar companions appear both non-coeval with their primary stars according
to evolutionary models and, as a group, are systematically more luminous than
the Upper Sco cluster sequence. One possible reason for these luminosity
discrepancies could be different formation processes or accretion histories for
these objects.


title: A simple model of many-body localization

abstract:
  We study a simple and tractable model of many-body localization. The main
idea is to take a renormalization group perspective in which local entanglement
is removed to reach a product state. The model is built from a random local
unitary which implements a real space renormalization procedure and a fixed
point Hamiltonian with random exponentially decaying interactions. We prove
that every energy eigenstate is localized, that energy is not transported, and
argue that despite being fine tuned, the model is stable to perturbations. We
also show that every energy eigenstate obeys an area law for entanglement
entropy and we consider the dynamics of entanglement entropy under
perturbations. In the case of extensive pertubations we recover a logarithmic
growth of entanglement observed in recent numerical simulations.


title: Theoretical Evolution of Optical Strong Lines across Cosmic Time

abstract:
  We use the chemical evolution predictions of cosmological hydrodynamic
simulations with our latest theoretical stellar population synthesis,
photoionization and shock models to predict the strong line evolution of
ensembles of galaxies from z=3 to the present day. In this paper, we focus on
the brightest optical emission-line ratios, [NII]/H-alpha and [OIII]/H-beta. We
use the optical diagnostic Baldwin-Phillips-Terlevich (BPT) diagram as a tool
for investigating the spectral properties of ensembles of active galaxies. We
use four redshift windows chosen to exploit new near-infrared multi-object
spectrographs. We predict how the BPT diagram will appear in these four
redshift windows given different sets of assumptions. We show that the position
of star-forming galaxies on the BPT diagram traces the ISM conditions and
radiation field in galaxies at a given redshift. Galaxies containing AGN form a
mixing sequence with purely star-forming galaxies. This mixing sequence may
change dramatically with cosmic time, due to the metallicity sensitivity of the
optical emission-lines. Furthermore, the position of the mixing sequence may
probe metallicity gradients in galaxies as a function of redshift, depending on
the size of the AGN narrow line region. We apply our latest slow shock models
for gas shocked by galactic-scale winds. We show that at high redshift,
galactic wind shocks are clearly separated from AGN in line ratio space.
Instead, shocks from galactic winds mimic high metallicity starburst galaxies.
We discuss our models in the context of future large near-infrared
spectroscopic surveys.


title: U-duality covariant gravity

abstract:
  We extend the techniques of double field theory to more general gravity
theories and U-duality symmetries, having in mind applications to the complete
D=11 supergravity. In this paper we work out a (3+3)-dimensional `U-duality
covariantization' of D=4 Einstein gravity, in which the Ehlers group SL(2,R) is
realized geometrically, acting in the 3 representation on half of the
coordinates. We include the full (2+1)-dimensional metric, while the `internal
vielbein' is a coset representative of SL(2,R)/SO(2) and transforms under gauge
transformations via generalized Lie derivatives. In addition, we introduce a
gauge connection of the `C-bracket', and a gauge connection of SL(2,R), albeit
subject to constraints. The action takes the form of (2+1)-dimensional gravity
coupled to a Chern-Simons-matter theory but encodes the complete D=4 Einstein
gravity. We comment on generalizations, such as an `$E_{8(8)}$
covariantization' of M-theory.


title: Distinguishing between lepton number violating scalars at the LHC

abstract:
  Scalars with lepton number violating interactions decaying into lepton pairs,
as those mediating the see-saw of type II, always include doubly-charged
components. If these are observed at the LHC, their electro-weak quantum
numbers can be determined through their leptonic decays in pair and single
production.


title: 3d dualities from 4d dualities for orthogonal groups

abstract:
  We extend recent work on the relation of 4d and 3d IR dualities of
supersymmetric gauge theories with four supercharges to the case of orthogonal
gauge groups. The distinction between different SO(N) gauge theories in 4d
plays an important role in this relation. We show that the 4d duality leads to
a 3d duality between an SO(N_c) gauge theory with N_f flavors and an
SO(N_f-N_c+2) theory with N_f flavors and extra singlets, and we derive its
generalization in the presence of Chern-Simons terms. There are two different
O(N) theories in 3d, which we denote by O(N)_\pm, and we also show that the
O(N_c)_- gauge theory is dual to a Spin(N_f-N_c+2) theory, and derive from 4d
the known duality between O(N_c)_+ and O(N_f-N_c+2)_+. We verify the
consistency of these 3d dualities by various methods, including index
computations.


title: Analysis of slope-intercept plots for arrays of electron field emitters

abstract:
  In electron field emission experiments, a linear relationship in plots of
slope vs. intercept obtained from Fowler-Nordheim analysis is commonly observed
for single tips or tip arrays. By simulating samples with many tips, it is
shown here that the observed linear relationship results from the distribution
of input parameters, assuming a log-normal distribution for the radius of each
tip. Typically, a shift from the lower-left to the upper-right of a
slope-intercept plot has been correlated with a shift in work function.
However, as shown in this paper, the same effect can result from a variation in
the number of emitters.


title:
Domain-wall melting in ultracold boson systems with holes and spin-flip
  defects

abstract:
  Quantum magnetism is a fundamental phenomenon of nature. As of late, it has
garnered a lot of interest because experiments with ultracold atomic gases in
optical lattices could be used as a simulator for phenomena of magnetic
systems. A paradigmatic example is the time evolution of a domain-wall state of
a spin-1/2 Heisenberg chain, the so-called domain-wall melting. The model can
be implemented by having two species of bosonic atoms with unity filling and
strong on-site repulsion U in an optical lattice. In this paper, we study the
domain-wall melting in such a setup on the basis of the time-dependent density
matrix renormalization group (tDMRG). We are particularly interested in the
effects of defects that originate from an imperfect preparation of the initial
state. Typical defects are holes (empty sites) and flipped spins. We show that
the dominating effects of holes on observables like the spatially resolved
magnetization can be taken account of by a linear combination of spatially
shifted observables from the clean case. For sufficiently large U, further
effects due to holes become negligible. In contrast, the effects of spin flips
are more severe as their dynamics occur on the same time scale as that of the
domain-wall melting itself. It is hence advisable to avoid preparation schemes
that are based on spin-flips.


title: The Cosmic BPT Diagram: Confronting Theory with Observations

abstract:
  We compare a large sample of galaxies between 0.5<z<2.6 with theoretical
predictions for how the optical diagnostic line ratios in galaxy ensembles
change as a function of cosmic time. We show that star forming galaxies at high
redshift (z>1.5) are consistent with a model in which the ISM conditions are
more extreme at high redshift than seen in the global spectra of local
galaxies. We speculate that global spectra of our high redshift galaxies may be
dominated by HII regions similar to the extreme clumpy, dense star-forming
complexes in the Antennae and M82. The transition to local-type conditions
occurs between 0.8<z<1.5. We conclude that classification schemes developed for
local samples should not be applied at high redshift (z > 1.5). We use our
theoretical models to derive a new redshift-dependent classification line that
utilizes the standard optical diagnostic line ratios [OIII]/H-beta and
[NII]/H-alpha. Our new line can be used to separate star-forming galaxies from
AGN between z=0 to z~3.5. We anticipate that our redshift-dependent optical
classification line will be useful for future large surveys with near-infrared
multi-object spectrographs. We apply our classification line to a sample of
gravitationally lensed galaxies at z~2.5. Although limited by small numbers, we
show that our classification line is consistent with the position of AGN that
have been independently confirmed via other methods.


title:
Stabilizing Cloud Feedback Dramatically Expands the Habitable Zone of
  Tidally Locked Planets

abstract:
  The habitable zone (HZ) is the circumstellar region where a planet can
sustain surface liquid water. Searching for terrestrial planets in the HZ of
nearby stars is the stated goal of ongoing and planned extrasolar planet
surveys. Previous estimates of the inner edge of the HZ were based on
one-dimensional radiative-convective models. The most serious limitation of
these models is the inability to predict cloud behavior. Here we use global
climate models with sophisticated cloud schemes to show that due to a
stabilizing cloud feedback, tidally locked planets can be habitable at twice
the stellar flux found by previous studies. This dramatically expands the HZ
and roughly doubles the frequency of habitable planets orbiting red dwarf
stars. At high stellar flux, strong convection produces thick water clouds near
the substellar location that greatly increase the planetary albedo and reduce
surface temperatures. Higher insolation produces stronger substellar convection
and therefore higher albedo, making this phenomenon a stabilizing climate
feedback. Substellar clouds also effectively block outgoing radiation from the
surface, reducing or even completely reversing the thermal emission contrast
between dayside and nightside. The presence of substellar water clouds and the
resulting clement surface conditions will therefore be detectable with the
James Webb Space Telescope.


title: Dynamical Structure of a Traditional Amazonian Social Network

abstract:
  Reciprocity is a vital feature of social networks, but relatively little is
known about its temporal structure or the mechanisms underlying its persistence
in real world behavior. In pursuit of these two questions, we study the
stationary and dynamical signals of reciprocity in a network of manioc beer
(Spanish: chicha; Tsimane': shocdye') drinking events in a Tsimane' village in
lowland Bolivia. At the stationary level, our analysis reveals that social
exchange within the community is heterogeneously patterned according to kinship
and spatial proximity. A positive relationship between the frequencies at which
two families host each other, controlling for kinship and proximity, provides
evidence for stationary reciprocity. Our analysis of the dynamical structure of
this network presents a novel method for the study of conditional, or
non-stationary, reciprocity effects. We find evidence that short-timescale
reciprocity (within three days) is present among non- and distant-kin pairs;
conversely, we find that levels of cooperation among close kin can be accounted
for on the stationary hypothesis alone.


title:
Relativistic Fluids, Superfluids, Solids and Supersolids from a Coset
  Construction

abstract:
  We provide a systematic coset construction of the effective field theories
governing the low-energy dynamics of relativistic fluids and solids, and of
their "super" counterparts. These effective theories agree with those
previously derived via different techniques. As an application of our methods,
we re-derive the Wess-Zumino term relevant for anomalous charge-carrying fluids
in (1+1) dimensions.


title: Diagonal approximation and the cohomology ring of torus fiber bundles

abstract:
  For a torus bundle (S^1 x S^1) -> E -> S^1$, we construct a finite free
resolution Z over ZG, where G is the fundamental group of the total space E,
and then we compute the cohomology groups H^*(G,Z) and H^*(G,Z_p) for a prime
p. We also construct a partial diagonal approximation for the resolution, which
allows us to compute the cup product in H^*(G,Z) and H^*(G,Z_p).


title: Fate of CP(N-1) fixed points with q-monopoles

abstract:
  We present an extensive quantum Monte Carlo study of the N\'eel-valence bond
solid (VBS) phase transition on rectangular and honeycomb lattice SU($N$)
antiferromagnets in sign problem free models. We find that in contrast to the
honeycomb lattice and previously studied square lattice systems, on the
rectangular lattice for small $N$ a first order N\'eel-VBS transition is
realized. On increasing $N\geq 4$, we observe that the transition becomes
continuous and with the {\em same} universal exponents as found on the
honeycomb and square lattices (studied here for $N=5,7,10$), providing strong
support for a deconfined quantum critical point. Combining our new results with
previous numerical and analytical studies we present a general phase diagram of
the stability of $\mathbb{CP}^{N-1}$ fixed points with $q$-monopoles.


title: Waveform cross correlation applied to earthquakes in the Atlantic Ocean

abstract:
  We assess the level of cross correlation between P-waves generated by
earthquakes in the Atlantic Ocean and measured by 22 array stations of the
International Monitoring System (IMS). There are 931 events with 6,411 arrivals
in 2011 and 2012. Station TORD was the most sensitive and detected 868 from 931
events. We constructed several 931 by 931 matrices of cross correlation
coefficients (CCs) for individual stations and also for average and cumulative
CCs. These matrices characterize the detection performance of the involved
stations and the IMS. Sixty earthquakes located in the northern hemisphere were
selected as master events for signal detection and building of events
populating a cross correlation Standard Event List (XSEL) for the first halves
of 2009 and 2012. High-quality signals (SNR>5.0) recorded by 10 most sensitive
stations were used as waveform templates. In order to quantitatively estimate
the gain in the completeness and resolution of the XSEL we compared it with the
Reviewed Event Bulletin (REB) of the International Data Centre (IDC) for the
North Atlantic (NA) and with the ISC Bulletin. Machine learning and
classification algorithms were successfully applied to automatically reject
invalid events in the XSEL for 2009.


title: Complete density perturbations in the Jordan-Fierz-Brans-Dicke theory

abstract:
  In the context of scalar-tensor theories we study the evolution of the
density contrast for Jordan-Fierz-Brans-Dicke theories in a
Friedmann-Lemaitre-Robertson-Walker Universe. Calculations are performed in the
Einstein Frame with the cosmological background described as Lambda-Cold Dark
Matter (Lambda-CDM) and supplemented by a Jordan-Fierz-Brans-Dicke field. By
using a completely general procedure valid for all scalar-tensor theories, we
obtain the exact fourth-order differential equation for the density contrast
evolution in modes of arbitrary size. In the case of sub-Hubble modes, the
expression reduces to a simpler but still fourth-order equation that is then
compared with the standard (quasistatic) approximation. Differences with
respect to the evolution as predicted by the standard Concordance Lambda-CDM
model are observed depending on the value of the coupling.


title:
Generalized Alpha Investing: Definitions, Optimality Results, and
  Application to Public Databases

abstract:
  The increasing prevalence and utility of large, public databases necessitates
the development of appropriate methods for controlling false discovery.
Motivated by this challenge, we discuss the generic problem of testing a
possibly infinite stream of null hypotheses. In this context, Foster and Stine
(2008) suggested a novel method named Alpha Investing for controlling a false
discovery measure known as mFDR. We develop a more general procedure for
controlling mFDR, of which Alpha Investing is a special case. We show that in
common, practical situations, the general procedure can be optimized to produce
an expected reward optimal (ERO) version, which is more powerful than Alpha
Investing.
  We then present the concept of quality preserving databases (QPD), originally
introduced in Aharoni et al. (2011), which formalizes efficient public database
management to simultaneously save costs and control false discovery. We show
how one variant of generalized alpha investing can be used to control mFDR in a
QPD and lead to significant reduction in costs compared to naive approaches for
controlling the Family-Wise Error Rate implemented in Aharoni et al. (2011).


title: What is integrability of discrete variational systems?

abstract:
  We propose a notion of a pluri-Lagrangian problem, which should be understood
as an analog of multi-dimensional consistency for variational systems. This is
a development along the line of research of discrete integrable Lagrangian
systems initiated in 2009 by Lobb and Nijhoff, however having its more remote
roots in the theory of pluriharmonic functions, in the Z-invariant models of
statistical mechanics and their quasiclassical limit, as well as in the theory
of variational symmetries going back to Noether. A d-dimensional
pluri-Lagrangian problem can be described as follows: given a d-form L on an
m-dimensional space (called multi-time, m>d), whose coefficients depend on a
sought-after function x of m independent variables (called field), find those
fields x which deliver critical points to the action functionals
$S_{\Sigma}=\int_{\Sigma} L$ for any d-dimensional manifold $\Sigma$ in the
multi-time. We derive the main building blocks of the multi-time Euler-Lagrange
equations for a discrete pluri-Lagrangian problem with d=2, the so called
corner equations, and discuss the notion of consistency of the system of corner
equations. We analyze the system of corner equations for a special class of
three-point 2-forms, corresponding to integrable quad-equations of the ABS
list. This allows us to close a conceptual gap of the work by Lobb and Nijhoff
by showing that the corresponding 2-forms are closed not only on solutions of
(non-variational) quad-equations, but also on general solutions of the
corresponding corner equations. We also find an example of a pluri-Lagrangian
system not coming from a multidimensionally consistent system of
quad-equations.


title:
Cuts, Cancellations and the Closed Time Path: The Soft Leptogenesis
  Example

abstract:
  By including all leading quantum-statistical effects at finite temperature,
we show that no net asymmetry of leptons and sleptons is generated from soft
leptogenesis, save the possible contribution from the resonant mixing of
sneutrinos. This result contrasts with different conclusions appearing in the
literature that are based on an incomplete inclusion of quantum statistics. We
discuss vertex and wave-function diagrams as well as all different possible
kinematic cuts that nominally lead to CP-violating asymmetries. The present
example of soft leptogenesis may therefore serve as a paradigm in order to
identify more generally applicable caveats relevant to alternative scenarios
for baryogenesis and leptogenesis, and it may provide useful guidance in
constructing viable models.


title:
Transport via double constrictions in integer and fractional topological
  insulators

abstract:
  We study transport properties of the helical edge states of two-dimensional
integer and fractional topological insulators via double constrictions. Such
constrictions couple the upper and lower edges of the sample, and can be made
and tuned by adding side gates to the system. Using renormalization group and
duality mapping, we analyze phase diagrams and transport properties in each of
these cases. Most interesting is the case of two constrictions tuned to
resonance, where we obtain Kondo behavior, with a tunable Kondo temperature.
Moving away from resonance gives the possibility of a metal-insulator
transition at some finite detuning. For integer topological insulators, this
physics is predicted to occur for realistic interaction strengths and gives a
conductance $G$ with two temperature $T$ scales where the sign of $dG/dT$
changes; one being related to the Kondo temperature while the other is related
to the detuning.


title:
Dynamics of a spherical object of uniform density in an expanding
  universe

abstract:
  We present Newtonian and fully general-relativistic solutions for the
evolution of a spherical region of uniform interior density \rho_i(t), embedded
in a background of uniform exterior density \rho_e(t). In both regions, the
fluid is assumed to support pressure. In general, the expansion rates of the
two regions, expressed in terms of interior and exterior Hubble parameters
H_i(t) and H_e(t), respectively, are independent. We consider in detail two
special cases: an object with a static boundary, H_i(t)=0; and an object whose
internal Hubble parameter matches that of the background, H_i(t)=H_e(t). In the
latter case, we also obtain fully general-relativistic expressions for the
force required to keep a test particle at rest inside the object, and that
required to keep a test particle on the moving boundary. We also derive a
generalised form of the Oppenheimer-Volkov equation, valid for general
time-dependent spherically-symmetric systems, which may be of interest in its
own right.


title:
Classification and environmental properties of X-ray selected point-like
  sources in the XMM-LSS field

abstract:
  The XMM-Large Scale Structure survey, covering an area of 11.1 sq. deg.,
contains more than 6000 X-ray point-like sources detected with XMM-Newton down
to a flux of 3x10^-15 erg s^-1 cm^-2 in the [0.5-2] keV band, the vast majority
of which have optical (CFHTLS), infrared (SWIRE), near-infrared (UKIDSS) and/or
ultraviolet (GALEX) counterparts. We wish to investigate the environmental
properties of the different types of the XMM-LSS X-ray sources, defining their
environment using the i-band CFHTLS W1 catalog of optical galaxies down to a
magnitude limit of 23.5 mag. We have classified 4435 X-ray selected sources on
the basis of their spectra, SEDs and X-ray luminosity and estimated their
photometric redshifts, having 4-11 band photometry, with an accuracy
sigma=0.076 and 22.6% outliers for i<26 mag. We estimated the local
overdensities of 777 X-ray sources which have spectro-z or photo-z calculated
using more than 7 bands (accuracy sigma=0.061 with 13.8% outliers) within the
volume-limited region defined by 0.1<z<0.85 and -23.5<Mi<-20. Although X-ray
sources may be found in variety of environments, a large fraction (~55-60%), as
verified by comparing with the random expectations, reside in overdense
regions. The galaxy overdensities within which X-ray sources reside show a
positive recent redshift evolution. We also find that X-ray selected galaxies,
with respect to AGN, inhabit significantly higher galaxy overdensities,
although their spatial extent appear to be smaller than that of AGN. Hard AGN
(HR>=-0.2) are located in more overdense regions with respect to the Soft AGN
(HR<-0.2), a fact clearly seen in both redshift ranges, although it appears to
be stronger in the higher redshift range (0.55<z<0.85). Furthermore, the galaxy
overdensities (with d>1.5) within which Soft AGN are embedded appear to evolve
more rapidly with respect to the corresponding overdensities around Hard AGN.


title:
Complementarity and Classical Limit of Quantum Mechanics: Energy
  Measurement aspects

abstract:
  In the present contribution we discuss the role of experimental limitations
in the classical limit problem. We studied some simple models and found that
Quantum Mechanics does not re-produce classical mechanical predictions, unless
we consider the experimental limitations ruled by uncertainty principle. We
have shown that the discrete nature of energy levels of integrable systems can
be accessed by classical measurements. We have defined a precise limit for this
procedure. It may be used as a tool to define the classical limit as far as the
discrete spectra of integrable systems are concerned. If a diffusive
environment is considered, we conclude that the "lifetime" of discreteness is
approximately $1/\kappa$ ($\kappa$ is the diffusion constant), thus it was
possible to relate the classical limit of a spectra with the action of an
environment and experimental resolution.


title: Long-Term Multiwavelength Studies of High-Redshift Blazar 0836+710

abstract:
  Aims. The observation of gamma -ray flares from blazar 0836+710 in 2011,
following a period of quiescence, offered an opportunity to study correlated
activity at different wavelengths for a high-redshift (z=2.218) active galactic
nucleus. Methods. Optical and radio monitoring, plus Fermi-LAT gamma-ray
monitoring provided 2008-2012 coverage, while Swift offered auxiliary optical,
ultraviolet, and X-ray information. Other contemporaneous observations were
used to construct a broad-band spectral energy distribution. Results. There is
evidence of correlation but not a measurable lag between the optical and
gamma-ray flaring emission. On the contrary, there is no clear correlation
between radio and gamma-ray activity, indicating radio emission regions that
are unrelated to the parts of the jet that produce the gamma-rays. The
gamma-ray energy spectrum is unusual in showing a change of shape from a power
law to a curved spectrum when going from the quiescent state to the active
state.


title:
Information-Entropic Stability Bound for Compact Objects: Application to
  Q-Balls and the Chandrasekhar Limit of Polytropes

abstract:
  Spatially-bound objects across diverse length and energy scales are
characterized by a binding energy. We propose that their spatial structure is
mathematically encoded as information in their momentum modes and described by
a measure known as configurational entropy (CE). Investigating solitonic
Q-balls and stars with a polytropic equation of state $P = K{\rho}^{\gamma}$,
we show that objects with large binding energy have low CE, whereas those at
the brink of instability (zero binding energy) have near maximal CE. In
particular, we use the CE to find the critical charge allowing for classically
stable Q-balls and the Chandrasekhar limit for white dwarfs $({\gamma} = 4/3)$
with an accuracy of a few percent.

categories: hep-th astro-ph.SR nlin.PS physics.comp-ph


title:
An Experimental Comparison of Speed Scaling Algorithms with Deadline
  Feasibility Constraints

abstract:
  We consider the first, and most well studied, speed scaling problem in the
algorithmic literature: where the scheduling quality of service measure is a
deadline feasibility constraint, and where the power objective is to minimize
the total energy used. Four online algorithms for this problem have been
proposed in the algorithmic literature. Based on the best upper bound that can
be proved on the competitive ratio, the ranking of the online algorithms from
best to worst is: $\qOA$, $\OA$, $\AVR$, $\BKP$. As a test case on the
effectiveness of competitive analysis to predict the best online algorithm, we
report on an experimental "horse race" between these algorithms using instances
based on web server traces. Our main conclusion is that the ranking of our
algorithms based on their performance in our experiments is identical to the
order predicted by competitive analysis. This ranking holds over a large range
of possible power functions, and even if the power objective is temperature.


title:
On two-dimensional supersymmetric quantum mechanics, pseudoanalytic
  functions and transmutation operators

abstract:
  Pseudoanalytic function theory is considered to study a two-dimensional
supersymmetric quantum mechanics system. Hamiltonian components of the
superhamiltonian are factorized in terms of one Vekua and one Bers derivative
operators. We show that imaginary and real solutions of a Vekua equation and
its Bers derivative are ground state solutions for the superhamiltonian. The
two-dimensional Darboux and pseudo-Darboux transformations correspond to Bers
derivatives in the complex plane. Results on the completeness of the ground
states are obtained. Finally, superpotential is studied in the separable case
in terms of transmutation operators. We show how Hamiltonian components of the
superhamiltonian are related to the Laplacian operator using these
transmutation operators.


title: Maximizing measures for expanding transformations

abstract:
  On a one-sided shift of finite type we prove that for a generic Holder
continuous function there is a unique maximizing measure. We show that b-Holder
continuous functions can be approximated in the a-Holder topology, a<b, by a
function whose maximizing measure is supported on a periodic orbit. We also
show that maximizing measures can be obtained as weak limits of equilibrium
states.
  We apply these theorems to the class of C(1+a) endomorphisms of the circle
which are coverings of degree 2, uniformly expanding and orientation
preserving. We prove that generically the invariant probability which maximizes
the Lyapunov exponent is unique and that C(1+b) endomorphisms can be
approximated in the C(1+a) topology by endomorphisms whose Lyapunov maximizing
measure is supported on a periodic orbit.


title:
Folding model study of the charge-exchange scattering to the isobaric
  analog state and implication for the nuclear symmetry energy

abstract:
  The Fermi transition (\Delta L=\Delta S=0 and \Delta T=1) between the nuclear
isobaric analog states (IAS), induced by the charge-exchange (p,n) or (3He,t)
reaction, can be considered as "elastic" scattering of proton or 3He by the
isovector term of the optical potential (OP) that flips the projectile isospin.
The accurately measured (p,n) or (3He,t) scattering cross-section to the IAS
can be used, therefore, to probe the isospin dependence of the proton or 3He
optical potential. Within the folding model, the isovector part of the OP is
determined exclusively by the neutron-proton difference in the nuclear
densities and the isospin dependence of the effective nucleon-nucleon (NN)
interaction. Because the isovector coupling explicitly links the isovector part
of the proton or 3He optical potential to the cross section of the
charge-exchange (p,n) or (3He,t) scattering to the IAS, the isospin dependence
of the effective (in-medium) NN interaction can be well tested in the folding
model analysis of these charge-exchange reactions. On the other hand, the same
isospin- and density dependent NN interaction can also be used in a
Hartree-Fock calculation of asymmetric nuclear matter, to estimate the nuclear
matter energy and its asymmetry part (the nuclear symmetry energy). As a
result, the fine-tuning of the isospin dependence of the effective NN
interaction against the measured (p,n) or (3He,t) cross sections should allow
us to make some realistic prediction of the nuclear symmetry energy and its
density dependence.


title: Proton stability in low-scale extra-dimensional grand unified theories

abstract:
  We propose an extra-dimensional mechanism that adequately suppresses the rate
of proton decay mediated by the X-bosons in grand unified theories. The
X-bosons and their Kaluza-Klein modes are localized in the extra spatial
dimensions due to the kink configuration of the adjoint Higgs multiplet that is
responsible for the spontaneous breaking of the unified gauge group while the
standard model gauge bosons freely propagate in the bulk. By localizing fermion
multiplets apart from the X-bosons in the extra dimensions, the resulting
four-dimensional couplings that give rise to proton decay are exponentially
suppressed, leading to the longevity of proton even when the mass scale of the
X-bosons is much lower than the usual unification scale.


title:
The Principle of Stationary Action in Biophysics: Stability in Protein
  Folding

abstract:
  Processes that proceed reliably from a variety of initial conditions to a
unique final form, regardless of moderately changing conditions, are of obvious
importance in biophysics. Protein folding is a case in point. We show that the
action principle can be applied directly to study the stability of biological
processes. The action principle in classical physics starts with the first
variation of the action and leads immediately to the equations of motion. The
second variation of the action leads in a natural way to powerful theorems that
provide quantitative treatment of stability and focusing and also explain how
some very complex processes can behave as though some seemingly important
forces drop out. We first apply these ideas to the non-equilibrium states
involved in two-state folding. We treat torsional waves and use the action
principle to talk about critical points in the dynamics. For some proteins the
theory resembles TST. We reach several quantitative and qualitative
conclusions. Besides giving an explanation of why TST often works in folding,
we find that the apparent smoothness of the energy funnel is a natural
consequence of the putative critical points in the dynamics. These ideas also
explain why biological proteins fold to unique states and random polymers do
not. The insensitivity to perturbations which follows from the presence of
critical points explains how folding to a unique shape occurs in the presence
of dilute denaturing agents in spite of the fact that those agents disrupt the
folded structure of the native state. This paper contributes to the theoretical
armamentarium by directing attention to the logical progression from first
physical principles to the stability theorems related to catastrophe theory as
applied to folding. This can potentially have the same success in biophysics as
it has enjoyed in optics.


title:
The Pioneer Anomaly: an inconvenient reality or NASA's 12 year
  misconception?

abstract:
  This paper discusses the likelihood of whether the Pioneer anomaly is due to
'mundane' systematic errors/effects or indicative of new or unappreciated
physics. The main aim of this paper is to argue that recent publications
suggesting that the anomaly is previously overlooked thermal recoil forces,
which is in stark contrast to the earlier consensus (1998-2010), are open to
questioning. Both direct and circumstantial evidence are examined, and the
uncertainty or inaccuracy associated with observations of such a small
magnitude effect is recognised. Whilst a non-systematic based anomaly appears
to be very unlikely, by way of the awkwardness of the observational
characteristics that would need to be modelled, the existence of other
peripheral anomalous phenomena makes an outright dismissal of the anomaly
unwise. Issues from the philosophy of science (and physics) are also tabled. In
the interests of having a contingency plan, should future experiments provide
support for a Pioneer-like anomaly, the type of unappreciated physics that
could conceivably satisfy the awkward observational evidence is alluded to,
albeit in a non-rigorous and cursory manner.


title: Fibered Knots and Virtual Knots

abstract:
  We introduce a new technique for studying classical knots with the methods of
virtual knot theory. Let $K$ be a knot and $J$ a knot in the complement of $K$
with $\text{lk}(J,K)=0$. Suppose there is covering space $\pi_J: \Sigma \times
(0,1) \to \bar{S^3\backslash V(J)}$, where $V(J)$ is a regular neighborhood of
$J$ satisfying $V(J) \cap \text{im}(K)=\emptyset$ and $\Sigma$ is a connected
compact orientable 2-manifold. Let $K'$ be a knot in $\Sigma \times (0,1)$ such
that $\pi_J(K')=K$. Then $K'$ stabilizes to a virtual knot $\hat{K}$, called a
virtual cover of $K$ relative to $J$. We investigate what can be said about a
classical knot from its virtual covers in the case that $J$ is a fibered knot.
Several examples and applications to classical knots are presented. A basic
theory of virtual covers is established.


title: The Evolution of Beliefs over Signed Social Networks

abstract:
  We study the evolution of opinions (or beliefs) over a social network modeled
as a signed graph. The sign attached to an edge in this graph characterizes
whether the corresponding individuals or end nodes are friends (positive links)
or enemies (negative links). Pairs of nodes are randomly selected to interact
over time, and when two nodes interact, each of them updates its opinion based
on the opinion of the other node and the sign of the corresponding link. This
model generalizes DeGroot model to account for negative links: when two enemies
interact, their opinions go in opposite directions. We provide conditions for
convergence and divergence in expectation, in mean-square, and in almost sure
sense, and exhibit phase transition phenomena for these notions of convergence
depending on the parameters of the opinion update model and on the structure of
the underlying graph. We establish a {\it no-survivor} theorem, stating that
the difference in opinions of any two nodes diverges whenever opinions in the
network diverge as a whole. We also prove a {\it live-or-die} lemma, indicating
that almost surely, the opinions either converge to an agreement or diverge.
Finally, we extend our analysis to cases where opinions have hard lower and
upper limits. In these cases, we study when and how opinions may become
asymptotically clustered to the belief boundaries, and highlight the crucial
influence of (strong or weak) structural balance of the underlying network on
this clustering phenomenon.


title: Anomaly induced transport coefficients, from weak to strong coupling

abstract:
  The existence of new transport phenomena associated to the presence of
quantum anomalies has atracted very recently the attention of theorist. These
transport coefficient have very interesting properties, for example, they do
not renormalize. The most famous case of anomaly induced transport phenomena is
the Chiral Magnetic Effect, in which an electric current is produced by a
magnetic field if the system has a different number of right handed fermions
respect the left handed one. In this thesis we have studied those transport
coefficients from Kubo formulas at weak and strong coupling. To finish a
fluid/gravity approach is used to compute all the second order anomalous
coefficients in an anomalous conformal fluid.