pinecone/core-2020-05-10-deduplication huggingface dataset:
Next Generation Relativistic Models

The current generation of covariant mean-field models has had many successes
in calculations of bulk observables for medium to heavy nuclei, but there
remain many open questions. New challenges are confronted when trying to
systematically extend these models to reliably address nuclear structure
physics away from the line of stability. In this lecture, we discuss a
framework for the next generation of relativistic models that can address these
questions and challenges. We interpret nuclear mean-field approaches as
approximate implementations of Kohn-Sham density functional theory (DFT), which
is widely used in condensed matter and quantum chemistry applications. We look
to effective field theory (EFT) for a systematic approach to low-energy nuclear
physics that can provide the framework for nuclear DFT.Comment: 28 pp, 39 figs, invited lecture at 307. WE-Heraeus-Seminar,
  "Relativistic Structure Models for the Physics of Radioactive Nuclear Beams,"
  May 12-16, 2003, Bad Honnef, German
Covariant Effective Field Theory for Nuclear Structure and Nuclear
  Currents

Recent progress in Lorentz-covariant quantum field theories of the nuclear
many-body problem (quantum hadrodynamics or QHD) is discussed. The effective
field theory studied here contains nucleons, pions, isoscalar scalar (\sigma)
and vector (\omega) fields, and isovector vector (\rho) fields. The theory
exhibits a nonlinear realization of spontaneously broken SU(2)_L \times SU(2)_R
chiral symmetry and has three desirable features: it uses the same degrees of
freedom to describe the nuclear currents and the strong-interaction dynamics,
it satisfies the symmetries of the underlying theory of QCD, and its parameters
can be calibrated using strong-interaction phenomena, like hadron scattering or
the empirical properties of finite nuclei. Moreover, it has recently been
verified that for normal nuclear systems, it is possible to expand the
effective Lagrangian systematically in powers of the meson fields (and their
derivatives) and to truncate the expansion reliably after the first few orders.
Using a mean-field version of the energy functional, accurate quantitative
results are obtained for the bulk and single-particle properties of medium- and
heavy-mass nuclei. The importance of modern perspectives in effective field
theory and density functional theory for understanding these successes of QHD
is emphasized. The inclusion of hadronic electromagnetic structure and of
nonanalytic terms in the energy functional is also considered briefly. As a
further application, weak-interaction currents are studied in the QHD
framework. The axial-vector current, evaluated through the leading order in the
field expansion, satisfies both PCAC and the Goldberger--Treiman relation, and
the corresponding vector and axial-vector charges satisfy the familiar chiral
charge algebra to all orders in the pion field.Comment: 32 pages, 9 figures, LaTeX2e <2001/06/01> with svmult.cls and
  svmultphys.clo; invited lecture at 307. WE-Heraeus-Seminar, "Relativistic
  Structure Models for the Physics of Radioactive Nuclear Beams," 5/12-16/2003,
  Bad Honnef, Germany. Reference list put into correct order; four typos fixe
Exploring the nucleus in the context of low-energy QCD

These lecture notes address a central problem of theoretical nuclear physics:
how to establish a relationship between low-energy, non-perturbative QCD and
nuclear phenomenology which includes both nuclear matter and finite nuclei. We
develop a microscopic covariant description of nuclear many-body dynamics
constrained by chiral symmetry and in-medium QCD sum rules. A relativistic
point-coupling model is derived, based on an effective Lagrangian with
density-dependent contact interactions between nucleons. These interactions are
constructed from chiral one- and two-pion exchange, combined with the large
isoscalar nucleon self-energies that arise through changes in the quark
condensate and the quark density at finite baryon density. Nuclear binding and
saturation are almost completely generated by chiral (two-pion exchange)
fluctuations in combination with Pauli effects, whereas strong scalar and
vector fields of about equal magnitude and opposite sign, induced by changes of
the QCD vacuum in the presence of baryonic matter, generate the large effective
spin-orbit potential in finite nuclei. Promising results are found for the
nuclear matter equation of state and for the bulk and single-nucleon properties
of finite nuclei.Comment: 50 pages, 11 figures, invited lecture at 307. WE-Heraeus-Seminar,
  "Relativistic Structure Models for the Physics of Radioactive Nuclear Beams,"
  May 12-16, 2003, Bad Honnef, German
The Relativistic Dirac-Brueckner Approach to Nuclear Matter

An overview on the relativistic Dirac-Brueckner approach to the nuclear
many-body problem is given. Different approximation schemes are discussed, with
particular emphasis on the nuclear self-energy and the saturation mechanism of
nuclear matter. I will further discuss extensions of the standard approach,
amongst other things the inclusion of non-nucleonic degrees of freedom,
many-body forces and finally compare relativistic and non-relativistic
approaches.Comment: 28 pages, 12 figs, ref. added, invited lecture at 307.
  WE-Heraeus-Seminar, "Relativistic Structure Models for the Physics of
  Radioactive Nuclear Beams," May 12-16, 2003, Bad Honnef, German
Seismic and Flood Risk Evaluation in Spain\ud
from Historical Data

Floods and earthquakes are two of the natural processes that cause in Spain\ud
economic and social losses, with major effects on the first ones. In order to evaluate the risk\ud
(social damages and economical losses) associated with these processes, the available\ud
historical data and information on happened events (from bibliographical and documentary\ud
sources, press, files, data bases, etc.) has been compiled and analysed exhaustively, including\ud
also the information related to the economic and social losses (damages, victims, direct\ud
and indirect economical losses, governmental and insurance companies data, etc.). The\ud
analysis of the historical information has allowed to estimate the distribution and extent of\ud
the damages and losses due to floods and earthquakes in Spain, as well as the vulnerability\ud
of the national territory. The estimation of the damages and losses for the next three decades\ud
has been approached from the study of the flood and earthquake potential hazard in\ud
Spain, estimating the probabilities of occurrence of these processes with different magnitude/\ud
intensity for the period of reference. The present economic and social conditions of the\ud
territory have been considered, carrying out probabilistic estimations and valuing hypothetical\ud
situations of potential damage scenarios. The results allow to know the hazard\ud
(probability of occurrence of processes of certain magnitude) and risk degree (potential\ud
damages and losses) of every municipality of the country
Navigating through the RLATES Interface: A Web-Based Adaptive and Intelligent Educational System

10 pages, 4 figures.-- Contributed to: Workshop on Human Computer Interface for Semantic Web and Web Applications (HCI-SWWA’03). Part of the International Federated Conferences (OTM'03, Catania, Sicily, Italy, Nov 3-7, 2003).The paper shows the architecture of the RLATES system, an Adaptive and Intelligent Educational System that uses the Reinforcement Learning model (RL) in order to learn to teach each student individually, being adapted to their learning needs in each moment of the interaction. This paper is focused on the interface module of RLATES, describing how the student could navigate through the system interface and how this interface adjusts the page contents according to the user learning needs. For this adaptation, the system changes the links appearance of the page and the presentation of the system knowledge.Publicad
Shape representation and indexing based on region connection calculus and oriented matroid theory

International Conference on Discrete Geometry for Computer Imagery (DGCI), 2003, Naples (Italy)In this paper a novel method for indexing views of 3D objects is presented. The topological properties of the regions of the views of a set of objects are used to define an index based on the region connection calculus and oriented matroid theory. Both are formalisms for qualitative spatial representation and reasoning and are complementary in the sense that whereas the region connection calculus encodes information about connectivity of pairs of connected regions of the view, oriented matroids encode relative position of the disjoint regions of the view 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 candidates in object recognition processes.Peer Reviewe
Probability of intrinsic time-arrow from information loss

Time-arrow $s=+/-$, intrinsic to a concrete physical system, is associated
with the direction of information loss $\Delta I$ displayed by the random
evolution of the given system. When the information loss tends to zero the
intrinsic time-arrow becomes uncertain. We propose the heuristic relationship
$1/[1+exp(-s\Delta I)]$ for the probability of the intrinsic time-arrow. The
main parts of the present work are trying to confirm this heuristic equation.
The probability of intrinsic time arrow is defined by Bayesian inference from
the observed random process. From irreversible thermodynamic systems, the
proposed heuristic probabilities follow via the Gallavotti-Cohen relations
between time-reversed random processes. In order to explore the underlying
microscopic mechanism, a trivial microscopic process is analyzed and an obvious
discrepancy is identified. It can be resolved by quantum theory. The
corresponding trivial quantum process will exactly confirm the proposed
heuristic time-arrow probability.Comment: 13pp, revtex4, to appear in Proceedings of DICE 2002 (Springer, LNP
Dissipation, Emergent Quantization and Quantum Fluctuations

We review some aspects of the quantization of the damped harmonic oscillator.
We derive the exact action for a damped mechanical system in the frame of the
path integral formulation of the quantum Brownian motion problem developed by
Schwinger and by Feynman and Vernon. The doubling of the phase-space degrees of
freedom for dissipative systems and thermal field theories is discussed and the
doubled variables are related to quantum noise effects. The 't Hooft proposal,
according to which the loss of information due to dissipation in a classical
deterministic system manifests itself in the quantum features of the system, is
analyzed and the quantum spectrum of the harmonic oscillator is shown to be
originated from the dissipative character of the original classical
deterministic system.Comment: Invited talk at the International Workshop DICE2002 "Decoherence,
  Information, Complexity and Entropy" - Piombino (Tuscany), September 2-6,
  200
Quantum Mechanics and Discrete Time from "Timeless" Classical Dynamics

We study classical Hamiltonian systems in which the intrinsic proper time
evolution parameter is related through a probability distribution to the
physical time, which is assumed to be discrete. - This is motivated by the
``timeless'' reparametrization invariant model of a relativistic particle with
two compactified extradimensions. In this example, discrete physical time is
constructed based on quasi-local observables. - Generally, employing the
path-integral formulation of classical mechanics developed by Gozzi et al., we
show that these deterministic classical systems can be naturally described as
unitary quantum mechanical models. The emergent quantum Hamiltonian is derived
from the underlying classical one. It is closely related to the Liouville
operator. We demonstrate in several examples the necessity of regularization,
in order to arrive at quantum models with bounded spectrum and stable
groundstate.Comment: 24 pages, 1 figure. Lecture given at DICE 2002. To be published in:
  Decoherence and Entropy in Complex Systems, Lecture Notes in Physics
  (Springer-Verlag, Berlin 2003). - Comprises quant-ph/0306096 and
  gr-qc/0301109, additional reference
Decoherence and quantum trajectories

Decoherence is the process by which quantum systems interact and become
correlated with their external environments; quantum trajectories are a
powerful technique by which decohering systems can be resolved into stochastic
evolutions, conditioned on different possible ``measurements'' of the
environment. By calling on recently-developed tools from quantum information
theory, we can analyze simplified models of decoherence, explicitly quantifying
the flow of information and randomness between the system, the environment, and
potential observers.Comment: 14 pages, Springer LNP LaTeX macros, 1 figure in encapsulated
  postscript format. To appear in proceedings of DICE 200
Decoherence in Discrete Quantum Walks

We present an introduction to coined quantum walks on regular graphs, which
have been developed in the past few years as an alternative to quantum Fourier
transforms for underpinning algorithms for quantum computation. We then
describe our results on the effects of decoherence on these quantum walks on a
line, cycle and hypercube. We find high sensitivity to decoherence, increasing
with the number of steps in the walk, as the particle is becoming more
delocalised with each step. However, the effect of a small amount of
decoherence can be to enhance the properties of the quantum walk that are
desirable for the development of quantum algorithms, such as fast mixing times
to uniform distributions.Comment: 15 pages, Springer LNP latex style, submitted to Proceedings of DICE
  200
Decoherence and Quantum-state Measurement in Quantum Optics

This paper discusses work developed in recent years, in the domain of quantum
optics, which has led to a better understanding of the classical limit of
quantum mechanics. New techniques have been proposed, and experimentally
demonstrated, for characterizing and monitoring in real time the quantum state
of an electromagnetic field in a cavity. They allow the investigation of the
dynamics of the decoherence process by which a quantum-mechanical superposition
of coherent states of the field becomes a statistical mixture.Comment: 19 pages, 6 figures in encapsulated postscript format, Springer LNP
  LaTeX macros. To appear in the Proceedings of the Conference on Decoherence,
  Information, Complexity, and Entropy (DICE2002), Piombino, Italy, September,
  2002 (edited by T.Elze
Measurement and Information Extraction in Complex Dynamics Quantum
  Computation

We address the problem related to the extraction of the information in the
simulation of complex dynamics quantum computation. Here we present an example
where important information can be extracted efficiently by means of quantum
simulations. We show how to extract efficiently the localization length, the
mean square deviation and the system characteristic frequency. We show how this
methods work on a dynamical model, the Sawtooth Map, that is characterized by
very different dynamical regimes: from near integrable to fully developed
chaos; it also exhibits quantum dynamical localization.Comment: 8 pages, 4 figures, Proceeding of "First International Workshop
  DICE2002 - Piombino (Tuscany), (2002)
Generalization of Boltzmann Equilibration Dynamics

We propose a novel approach in the study of transport phenomena in dense
systems or systems with long range interactions where multiple particle
interactions must be taken into consideration. Within Boltzmann's kinetic
formalism, we study the influence of other interacting particles in terms of a
random distortion of energy and momentum conservation occurring when
multi-particle interactions are considered as binary collisions. Energy and
momentum conservation still holds exactly but not in each model binary
collision. We show how this new system differs from the Boltzmann system and we
note that our approach naturally explains the emergence of Tsallis-like
equilibrium statistics in physically relevant systems in terms of the long
since neglected physics of interacting and dense systems.Comment: 4 pages, references and clarifications adde
On the Emergence of Nonextensivity at the Edge of Quantum Chaos

We explore the border between regular and chaotic quantum dynamics,
characterized by a power law decrease in the overlap between a state evolved
under chaotic dynamics and the same state evolved under a slightly perturbed
dynamics. This region corresponds to the edge of chaos for the classical map
from which the quantum chaotic dynamics is derived and can be characterized via
nonextensive entropy concepts.Comment: Invited paper to appear in "Decoherence and Entropy in Complex
  Systems", ed. H.T. Elze, Lecture Notes in Physics (Springer, Heidelberg), in
  press. 13 pages including 6 figures and 1 tabl
Dynamics of Pure Shape, Relativity and the Problem of Time

A new approach to the dynamics of the universe based on work by O Murchadha,
Foster, Anderson and the author is presented. The only kinematics presupposed
is the spatial geometry needed to define configuration spaces in purely
relational terms. A new formulation of the relativity principle based on
Poincare's analysis of the problem of absolute and relative motion (Mach's
principle) is given. The enire dynamics is based on shape and nothing else. It
leads to much stronger predictions than standard Newtonian theory. For the
dynamics of Riemannian 3-geometries on which matter fields also evolve,
implementation of the new relativity principle establishes unexpected links
between special relativity, general relativity and the gauge principle. They
all emerge together as a self-consistent complex from a unified and completely
relational approach to dynamics. A connection between time and scale invariance
is established. In particular, the representation of general relativity as
evolution of the shape of space leads to unique definition of simultaneity.
This opens up the prospect of a solution of the problem of time in quantum
gravity on the basis of a fundamental dynamical principle.Comment: 17 pages. To appear in Decoherence and Entropy in Complex Systems
  (Proceedings of the Conference DICE, Piombino 2002, ed. H. -T. Elze, Spring
  Lecture Notes in Physics 2003
Covariant hamiltonian formalism for field theory: Hamilton-Jacobi
  equation on the space G

Hamiltonian mechanics of field theory can be formulated in a generally
covariant and background independent manner over a finite dimensional extended
configuration space. The physical symplectic structure of the theory can then
be defined over a space G of three-dimensional surfaces without boundary, in
the extended configuration space. These surfaces provide a preferred
over-coordinatization of phase space. I consider the covariant form of the
Hamilton-Jacobi equation on G, and a canonical function S on G which is a
preferred solution of the Hamilton-Jacobi equation. The application of this
formalism to general relativity is equivalent to the ADM formalism, but fully
covariant. In the quantum domain, it yields directly the
Ashtekar-Wheeler-DeWitt equation. Finally, I apply this formalism to discuss
the partial observables of a covariant field theory and the role of the spin
networks --basic objects in quantum gravity-- in the classical theory.Comment: 19 pages, no figure
Some Recent Developments in the Decoherent Histories Approach to Quantum
  Theory

A brief introduction to the decoherent histories approach to quantum theory
is given, with emphasis on its role in the discussion of the emergence of
classicality from quantum theory. Some applications are discussed, including
quantum-classical couplings, the relationship of the histories approach to
quantum state diffusion, and the application of the histories approach to
situations involving time in a non-trivial way.Comment: 26 pages, Latex. To appear in Proceedings of the Conference,
  Decoherence, Information, Complexity, Entropy (DICE), Piombino, Italy,
  September, 2002 (edited by T.Elze
Is there an information-loss problem for black holes?

Black holes emit thermal radiation (Hawking effect). If after black-hole
evaporation nothing else were left, an arbitrary initial state would evolve
into a thermal state (`information-loss problem'). Here it is argued that the
whole evolution is unitary and that the thermal nature of Hawking radiation
emerges solely through decoherence -- the irreversible interaction with further
degrees of freedom. For this purpose a detailed comparison with an analogous
case in cosmology (entropy of primordial fluctuations) is presented. Some
remarks on the possible origin of black-hole entropy due to interaction with
other degrees of freedom are added. This might concern the interaction with
quasi-normal modes or with background fields in string theory.Comment: 11 pages, to appear in the Proceedings of the conference DICE,
  Piombino 2002, ed. by H.-T. Elze (Springer 2003), references and
  clarifications adde
Towards a Statistical Geometrodynamics

Can the spatial distance between two identical particles be explained in
terms of the extent that one can be distinguished from the other? Is the
geometry of space a macroscopic manifestation of an underlying microscopic
statistical structure? Is geometrodynamics derivable from general principles of
inductive inference? Tentative answers are suggested by a model of
geometrodynamics based on the statistical concepts of entropy, information
geometry, and entropic dynamics.Comment: Invited talk at the Decoherence, Information, Entropy, and Complexity
  Workshop, DICE02, September 2000, Piombino, Ital
Microscopic Models of Heavy Ion Interactions

An introduction to dynamical microscopic models of hadronic and nuclear
interactions is presented. Special emphasis is put in the relation between
multiparticle production and total cross-section contributions. In heavy ion
collisions, some observables, considered as signals of the production of a
Quark Gluon Plasma (QGP), are studied. It is shown that they can only be
described if final state interactions are introduced. It is argued that the
cross-sections required are too small to drive the system to thermal
equilibrium within the duration time of the final state interaction.Comment: 39 pages, 18 figures. Lectures at VIII Hispalensis International
  Summer School, Seville (Spain), to be published by Springer Verla
Ultrarelativistic nucleus-nucleus collisions and the quark-gluon plasma

We present an overview of selected aspects of ultrarelativistic
nucleus-nucleus collisions, a research program devoted to the study of strongly
interacting matter at high energy densities and in particular to the
characterization of the quark-gluon plasma (QGP). The basic features of the
phase diagram of nuclear matter, as currently understood theoretically, are
discussed. The experimental program, carried out over a broad energy domain at
various accelerators, is briefly reviewed, with an emphasis on the global
characterization of nucleus-nucleus collisions. Two particular aspects are
treated in more detail: i) the application of statistical models to a
phenomenological description of particle production and the information it
provides on the phase diagram; ii) the production of hadrons carrying charm
quarks as messengers from the QGP phase.Comment: Based on lectures given by P.Braun-Munzinger at the VIII Hispalensis
  International Summer School, Oromana (Seville, Spain), June 9-21, 2003 32
  pages, 20 figures. A clickable list of references available at
  http://www-linux.gsi.de/~andronic/qgp/qgp.htm