pinecone/core-2020-05-10-deduplication huggingface dataset:
An Introduction to Nuclear Supersymmetry: a Unification Scheme for
  Nuclei

The main ideas behind nuclear supersymmetry are presented, starting from the
basic concepts of symmetry and the methods of group theory in physics. We
propose new, more stringent experimental tests that probe the supersymmetry
classification in nuclei and point out that specific correlations should exist
for particle transfer intensities among supersymmetric partners. We also
discuss possible ways to generalize these ideas to cases where no dynamical
symmetries are present. The combination of these theoretical and experimental
studies may play a unifying role in nuclear phenomena.Comment: 40 pages, 11 figures, lecture notes `VIII Hispalensis International
  Summer School: Exotic Nuclear Physics', Oromana, Sevilla, Spain, June 9-21,
  200
Stability of Spatial Optical Solitons

We present a brief overview of the basic concepts of the soliton stability
theory and discuss some characteristic examples of the instability-induced
soliton dynamics, in application to spatial optical solitons described by the
NLS-type nonlinear models and their generalizations. In particular, we
demonstrate that the soliton internal modes are responsible for the appearance
of the soliton instability, and outline an analytical approach based on a
multi-scale asymptotic technique that allows to analyze the soliton dynamics
near the marginal stability point. We also discuss some results of the rigorous
linear stability analysis of fundamental solitary waves and nonlinear impurity
modes. Finally, we demonstrate that multi-hump vector solitary waves may become
stable in some nonlinear models, and discuss the examples of stable
(1+1)-dimensional composite solitons and (2+1)-dimensional dipole-mode solitons
in a model of two incoherently interacting optical beams.Comment: 34 pages, 9 figures; to be published in: "Spatial Optical Solitons",
  Eds. W. Torruellas and S. Trillo (Springer, New York
Use of ENSO-based seasonal rainfall forecasting for informed cropping decisions by farmers in the SAT India

Dryland agriculture in India is practiced on 97 million ha of the cultivated area that supports 40% of the human population and 60% of livestock population by producing 44% of the food and fodder requirements. Even if India can achieve the full potential of irrigation in 139.5 million ha, still 75 million ha drylands would continue to depend on rainfall from southwest (SW) and northeast (NE) monsoons, characterized by high rainfall variability that cause most of production uncertainties. Thus dryland agriculture continues to play a crucial role in India’s food security. However, productivity gains have been relatively insignificant and risk-averse dryland farmers have to improve agricultural productivity with suitable management options and matching application of farm inputs to maximize crop productivity and income, while minimizing crop failure and input losses against uncertainties of seasonal weather to feed the booming populatio
The Cosmic Web: Geometric Analysis

The lecture notes describe the Delaunay Tessellation Field Estimator for
Cosmic Web analysis. The high sensitivity of Voronoi/Delaunay tessellations to
the local point distribution is used to obtain estimates of density and related
quantities. The adaptive and minimum triangulation properties of Delaunay
tessellations are utilized for interpolation to continuous volume-covering
density and velocity fields. The adaptivity to the local density and geometry
preserves three key characteristics of the cosmic matter distribution: 1) its
hierarchical nature,2) its anisotropic weblike morphology, 3) the presence and
structure of voids. The lecture notes discuss the mathematical context and
background of the DTFE method, in essence a first order version of Natural
Neighbour methods, smooth and higher order spatial interpolation techniques.
This is followed by an outline of the DTFE procedure. A series of tests on
spatially complex point distributions provides quantitative information on its
performance and noise characteristics. We conclude with a few cosmological
applications. The reconstruction of the spatial weblike patterns in N-body
simulations and in the 2dFGRS provide a visual impression of DTFE's
performance. The analysis of the velocity divergence pdf and maps obtained of
the velocity flow in the Local Universe (implied by PSCz) illustrate its
promise for probing the dynamics of cosmic structure. The Watershed Void Finder
(Platen et al. 2007), for the study of voids, and Multiscale Morphology Filter
(Aragon-Calvo et al. 2007), for identifying and analyzing weblike networks of
filaments, sheets and clusters, are based upon DTFE density fields. We also
mention SimpleX, a related random lattice radiative transfer formalism
(Ritzerveld & Icke 2006).Comment: 128 pp., 52+1 figures, lecture notes summerschool "Data Analysis in
  Cosmology" (Valencia), eds. V. Martinez, E. Saar, E. Martinez-Gonzalez, M.
  Pons-Borderia, Springer-Verlag. For high-res version see
  http://www.astro.rug.nl/~weygaert/tim1publication/weyval2004.pd
Self-Dual Chern-Simons Theories

In these lectures I review classical aspects of the self-dual Chern-Simons
systems which describe charged scalar fields in $2+1$ dimensions coupled to a
gauge field whose dynamics is provided by a pure Chern-Simons Lagrangian. These
self-dual models have one realization with nonrelativistic dynamics for the
scalar fields, and another with relativistic dynamics for the scalars. In each
model, the energy density may be minimized by a Bogomol'nyi bound which is
saturated by solutions to a set of first-order self-duality equations. In the
nonrelativistic case the self-dual potential is quartic, the system possesses a
dynamical conformal symmetry, and the self-dual solutions are equivalent to the
static zero energy solutions of the equations of motion. The nonrelativistic
self-duality equations are integrable and all finite charge solutions may be
found. In the relativistic case the self-dual potential is sixth order and the
self-dual Lagrangian may be embedded in a model with an extended supersymmetry.
The self-dual potential has a rich structure of degenerate classical minima,
and the vacuum masses generated by the Chern-Simons Higgs mechanism reflect the
self-dual nature of the potential.Comment: 42 pages LaTe
Electron Coherence in Mesoscopic Kondo Wires

We present measurements of the magnetoresistance of long and narrow quasi
one-dimensional gold wires containing magnetic iron impurities. The electron
phase coherence time extracted from the weak antilocalisation shows a
pronounced plateau in a temperature region of 300 mK - 800 mK, associated with
the phase breaking due to the Kondo effect. Below the Kondo temperature, the
phase coherence time increases, as expected in the framework of Kondo physics.
At much lower temperatures, the phase coherence time saturates again, in
contradiction with standard Fermi liquid theory. In the same temperature
regime, the resistivity curve displays a characteristic maximum at zero
magnetic field, associated with the formation of a spin glass state. We argue
that the interactions between the magnetic moments are responsible for the low
temperature saturation of the phase coherence time.Comment: To appear in Advances in Solid State Physics, Vol 43, edited by B.
  Kramer (Springer Verlag, Berlin 2003
Simulation of Transport and Gain in Quantum Cascade Lasers

Quantum cascade lasers can be modeled within a hierarchy of different
approaches: Standard rate equations for the electron densities in the levels,
semiclassical Boltzmann equation for the microscopic distribution functions,
and quantum kinetics including the coherent evolution between the states. Here
we present a quantum transport approach based on nonequilibrium Green
functions. This allows for quantitative simulations of the transport and
optical gain of the device. The division of the current density in two terms
shows that semiclassical transitions are likely to dominate the transport for
the prototype device of Sirtori et al. but not for a recent THz-laser with only
a few layers per period. The many particle effects are extremely dependent on
the design of the heterostructure, and for the case considered here, inclusion
of electron-electron interaction at the Hartree Fock level, provides a sizable
change in absorption but imparts only a minor shift of the gain peak.Comment: 12 pages, 5 figures included, to appear in in "Advances in Solid
  State Physics", ed. by B. Kramer (Springer 2003
From Digital to Analogue Magnetoelectronics: Theory of Transport in
  Non-Collinear Magnetic Nanostructures

Magnetoelectronics is mainly digital, i.e. governed by up and down
magnetizations. In contrast, analogue magnetoelectronics makes use of phenomena
occuring for non-collinear magnetization configurations. Here we review
theories which have recently been applied to the transport in non-collinear
magnetic nanostructures in two and multiterminal structures, viz. random matrix
and circuit theory. Both are not valid for highly transparent systems in a
resistive environment like perpendicular metallic spin valves. The solution to
this problem is a renormalization of the conventional and spin-mixing
conductance parameters.Comment: To be published in "Advance in Solid State Physics", edited by B.
  Kramer, Springer Verlag, Berlin, 200
Scale invariance and dynamic phase transitions in diffusion-limited
  reactions

Many systems that can be described in terms of diffusion-limited `chemical'
reactions display non-equilibrium continuous transitions separating active from
inactive, absorbing states, where stochastic fluctuations cease entirely. Their
critical properties can be analyzed via a path-integral representation of the
corresponding classical master equation, and the dynamical renormalization
group. An overview over the ensuing universality classes in single-species
processes is given, and generalizations to reactions with multiple particle
species are discussed as well. The generic case is represented by the processes
A <-> A + A, and A -> 0, which map onto Reggeon field theory with the critical
exponents of directed percolation (DP). For branching and annihilating random
walks (BARW) A -> (m+1) A and A + A -> 0, the mean-field rate equation predicts
an active state only. Yet BARW with odd m display a DP transition for d <= 2.
For even offspring number m, the particle number parity is conserved locally.
Below d_c' = 4/3, this leads to the emergence of an inactive phase that is
characterized by the power laws of the pair annihilation process. The critical
exponents at the transition are those of the `parity-conserving' (PC)
universality class. For local processes without memory, competing pair or
triplet annihilation and fission reactions k A -> (k - l) A, k A -> (k+m)A with
k=2,3 appear to yield the only other universality classes not described by
mean-field theory. In these reactions, site occupation number restrictions play
a crucial role.Comment: 16 pages, talk given at 2003 German Physical Society Spring Meeting;
  four figures and style files include
AC-Calorimetry at High Pressure and Low Temperature

Recent developments of the AC-calorimetric technique adapted for the needs of
high pressure experiments are discussed. A semi-quantitative measurement of the
specific heat with a Bridgman-type of pressure cell as well as a diamond anvil
cell is possible in the temperature range 0.1 K < T < 10 K. The pressure
transmitting medium used to ensure good pressure conditions determines to a
great extent via its thermal conductivity the operating frequency and thus the
accessible temperature range. Investigations with different pressure
transmitting media for T > 1.5 K reveal for solid He a cut-off frequency which
is considerably higher than for steatite. Experiments below 1 K and pressures
above 10 GPa clearly show that the pressure dependence of the linear
temperature coefficient of the specific heat can be measured. It is in
qualitative agreement to a related quantity obtained quasi-simultaneously by
electrical resistivity measurements on the same sample.Comment: 14 pages, 7 figures. The manuscript with high resoultion figures
  (pdf-file, about 1Mb) can be downloaded from http://www.cpfs.mpg.de/~wilhelm
Self-Organized InGaAs Quantum Rings -- Fabrication and Spectroscopy

13 páginas.-- The written version of the plenary and invited lectures of the Spring Meeting of the Condensed Matter Physics section of the Deutsche Physikalische Gesellschaft held from March 24 to 28, 2003 in Dresden, Germany.-- Kramer, Bernhard (Ed.).We report on recent experiments on semiconductor quantum rings, fabricated by self-organized Stranski-Krastanov growth. In the first part of this review we focus on the growth mechanisms that lead to formation of annular islands, with emphasis on the influence of diffusion and surface tension. In the second part, we summarize the results of intraband spectroscopy, which show the influence that the ring morphology has on the electronic properties, in particular, when a magnetic flux quantum threads the interior of the islands.Peer reviewe
Oriented matroids for shape representation and indexing

Iberian Conference on Pattern Recognition and Image Analysis (IbPRIA), Port d'Andratx (Spain)In this paper a novel method for indexing views of 3D objects is presented. The topological properties of the regions of the segmented images of the objects are used to define an index based on oriented matroid theory. Oriented matroids, which are projective invariants, encode incidence relations and relative position of the elements of the image and give local and global topological information about their spatial distribution. This indexing technique is applied to 3D object hypothesis generation from single views to reduce the number of candidates in object recognition processes.Peer Reviewe
Fusion of color and shape for object tracking under varying illumination

Iberian Conference on Pattern Recognition and Image Analysis (IbPRIA), 2003, Port d'Andratx (Spain)In this paper a new technique to perform tracking in cluttered scenarios with varying illumination conditions is presented. The robustness of the approach lies in the integration of appearance and structural information of the object. The fusion is done using the CONDENSATION algorithm that formulates multiple hypothesis about the estimation of the object's color distribution and validates them taking into account the contour information of the object.This work was supported by projects: 'Navegación autónoma de robots guiados por objetivos visuales' (070-720), 'Supervised learning of industrial scenes by means of an active vision equipped mobile robot.' (J-00063).Peer Reviewe
A Graph-based Clustering Approach to Evaluate Interestingness Measures: A Tool and a Comparative Study

Finding interestingness measures to evaluate association rules has become an important knowledge quality issue in KDD. Many interestingness measures may be found in the literature, and many authors have discussed and compared interestingness properties in order to improve the choice of the most suitable measures for a given application. As interestingness depends both on the data structure and on the decision-maker's goals, some measures may be relevant in some context, but not in others. Therefore, it is necessary to design new contextual approaches in order to help the decision-maker select the most suitable interestingness measures. In this paper, we present a new approach implemented by a new tool, ARQAT, for making comparisons. The approach is based on the analysis of a correlation graph presenting the clustering of objective interestingness measures and reflecting the post-processing of association rules. This graph-based clustering approach is used to compare and discuss the behavior of thirty-six interestingness measures on two prototypical and opposite datasets: a highly correlated one and a lowly correlated one. We focus on the discovery of the stable clusters obtained from the data analyzed between these thirty-six measures
Stability Analysis of a Metabolic Model with Sequential Feedback Inhibition

International audienceThis paper deals with the stability analysis of a simple metabolic system with feedback inhibition. The system is a sequence of monomolecular enzymatic reactions. The last metabolite acts as a feedback regulator for the first enzyme of the pathway. The enzymatic reactions of the pathway satisfy Michaelis-Menten kinetics. The inhibition is described by an hyperbolic model. Without inhibition, it is clear that the system is cooperative and has a single globally asymptotically stable equilibrium. But, in the common situation where there is inhibition, the system is no longer cooperative and the stability analysis is more intricate. In this paper we exhibit sufficient conditions on the kinetic parameters in order to guarantee that this simple metabolic system with inhibition still has a single globally asymptotically stable equilibrium
Mixing patterns and community structure in networks

Common experience suggests that many networks might possess community
structure - division of vertices into groups, with a higher density of edges
within groups than between them. Here we describe a new computer algorithm that
detects structure of this kind. We apply the algorithm to a number of
real-world networks and show that they do indeed possess non-trivial community
structure. We suggest a possible explanation for this structure in the
mechanism of assortative mixing, which is the preferential association of
network vertices with others that are like them in some way. We show by
simulation that this mechanism can indeed account for community structure. We
also look in detail at one particular example of assortative mixing, namely
mixing by vertex degree, in which vertices with similar degree prefer to be
connected to one another. We propose a measure for mixing of this type which we
apply to a variety of networks, and also discuss the implications for network
structure and the formation of a giant component in assortatively mixed
networks.Comment: 21 pages, 9 postscript figures, 2 table
Chaos and Chaotic Phase Mixing in Galaxy Evolution and Charged Particle Beams

This paper discusses three new issues that necessarily arise in realistic attempts to apply nonlinear dynamics to galaxy evolution, namely: (i) the meaning of chaos in many-body systems, (ii) the time-dependence of the bulk potential, which can trigger intervals of {\em transient chaos}, and (iii) the self-consistent nature of any bulk chaos, which is generated by the bodies themselves, rather than imposed externally. Simulations and theory both suggest strongly that the physical processes associated with galactic evolution should also act in nonneutral plasmas and charged particle beams. This in turn suggests the possibility of testing this physics in real laboratory experiments, an undertaking currently underway
Weak Homology of Bright Elliptical Galaxies

Studies of the Fundamental Plane of early-type galaxies, from small to intermediate redshifts, are often carried out under the guiding principle that the Fundamental Plane reflects the existence of an underlying mass-luminosity relation for such galaxies, in a scenario where elliptical galaxies are homologous systems in dynamical equilibrium. Here I will re-examine the issue of whether empirical evidence supports the view that significant systematic deviations from strict homology occur in the structure and dynamics of bright elliptical galaxies. In addition, I will discuss possible mechanisms of dynamical evolution for these systems, in the light of some classical thermodynamical arguments and of recent N-body simulations for stellar systems under the influence of weak collisionality
A SAURON view of galaxies

We have measured the two-dimensional kinematics and line-strength distributions of 72 representative nearby early-type galaxies, out to approximately one effective radius, with our panoramic integral-field spectrograph SAURON. The resulting maps reveal a rich variety in kinematical structures and linestrength distributions, indicating that early-type galaxies are more complex systems than often assumed. We are building detailed dynamical models for these galaxies, to derive their intrinsic shape and dynamical structure, and to determine the mass of the supermassive central black hole. Here we focus on two examples, the compact elliptical M32 and the E3 galaxy NGC4365. These objects represent two extreme cases: M32 has very regular kinematics which can be represented accurately by an axisymmetric model in which all stars rotate around the short axis, while NGC4365 is a triaxial galaxy with a prominent kinematically decoupled core, with an inner core that rotates about an axis that is nearly perpendicular to the rotation axis of the main body of the galaxy. Our dynamical models for these objects demonstrate that two-dimensional observations are essential for deriving the intrinsic orbital structure and dark matter content of galaxies
Major Mergers and the Origin of Elliptical Galaxies

The formation of elliptical galaxies as a result of the merging of spiral galaxies is discussed. We analyse a large set of numerical N-Body merger simulations which show that major mergers can in principle explain the observed isophotal fine structure of ellipticals and its correlation with kinematical properties. Equal-mass mergers lead to boxy, slowly rotating systems, unequal-mass mergers produce fast rotating and disky ellipticals. However, several problems remain. Anisotropic equal mass mergers appear disky under certain projections which is not observed. The intrinsic ellipticities of remnants are often larger than observed. Finally, although unequal-mass mergers produce fast rotating ellipticals, the remnants are in general more anisotropic than expected from observations. Additional processes seem to play an important role which are not included in dissipationless mergers. Resolving these problems might provide interesting new information on the structure and gas content of the progenitors of early-type galaxies
Collisionless evaporation from cluster elliptical galaxies

We describe a particular aspect of the effects of the parent cluster tidal field (CTF) on stellar orbits inside cluster Elliptical galaxies. In particular we discuss, with the aid of a simple numerical model, the possibility that collisionless stellar evaporation from elliptical galaxies is an effective mechanism for the production of the recently discovered intracluster stellar populations. A preliminary investigation, based on very idealized galaxy density profiles (Ferrers density distributions), showed that over an Hubble time, the amount of stars lost by a representative galaxy may sum up to the 10% of the initial galaxy mass, a fraction in interesting agreement with observational data. The effectiveness of this mechanism is due to the fact that the galaxy oscillation periods near equilibrium configurations in the CTF are comparable to stellar orbital times in the external galaxy regions. Here we extend our previous study to more realistic galaxy density profiles, in particular by adopting a triaxial Hernquist model
Jeans solutions for triaxial galaxies

The Jeans equations relate the second-order velocity moments to the density and potential of a stellar system. For general three-dimensional stellar systems, there are three equations, but these are not very helpful, as they contain six independent moments. By assuming that the potential is triaxial and of separable Staeckel form, the mixed moments vanish in confocal ellipsoidal coordinates. The three Jeans equations and three remaining non-vanishing moments form a closed system of three highly-symmetric coupled first-order partial differential equations in three variables. They were first derived by Lynden-Bell in 1960, but have resisted solution by standard methods. Here we present the general solution by superposition of singular solutions