


Modern Statistical Mechanics 
Posted on 20161025
(Send to a Friend )


Table of contents: Classical spin systems, order and disorder, introducing the Ising model and solving the 1d case, the transfer matrix, the Peierls argument; The quantum/classical correspondence, the Ising Hamiltonian;
Quantum spin systems, su(2) symmetry;
The 1 1 dimensional Ising model: the low and hightemperature expansions, duality, solving it using free fermions; The XXZ chain and the sixvertex model; Landau theory and the meanfield approximation; A Conformal Field Theory Primer. . . . . 






Electronic Structure Theory 
Posted on 20161024
(Send to a Friend )


The goal of electonic structure theory is to be predictive!
Computational Electronic Structure Theory is an evergrowing field which
combines theoretical physics and chemistry with computer science and math. . . . . 






What's (the) Matter?, A Show on Elementary Particle Physics. 
Posted on 20161017
(Send to a Friend )


We present the screenplay of a physics show on particle physics, by the Physikshow of Bonn University. The show is addressed at nonphysicists aged 14 and communicates basic concepts of elementary particle physics including the discovery of the Higgs boson in an entertaining fashion. It is also demonstrates a successful outreach activity heavily relying on the university physics students. This paper is addressed at anybody interested in particle physics and/or show physics. This paper is also addressed at fellow physicists working in outre . . . . 






The historical development of Xray Absorption Fine Spectroscopy and of its applications to Materials Science 
Posted on 20161012
(Send to a Friend )


This essay sketches the development of Xray Absorption Fine Spectroscopy (XAFS) ever since the second half of 20th century. At that time, synchrotrons started competing with Xray discharge tubes as the sources of the excitation able to show the pre and nearedge structures (XANES) and extended oscillations (EXAFS) that characterize the Xray absorption edge of solid matter. Actually, modern XAFS began after 1975, when the hardXray synchrotron radiation derived from storage rings took over. Ever since, XAFS greatly contributed to both techn . . . . 






Dynamical Screening Effects in Correlated Electron Materials  A Progress Report on Combined ManyBody Perturbation and DMFT 
Posted on 20161012
(Send to a Friend )


We give a summary of recent progress in the field of electronic structure calculations for materials with strong electronic Coulomb correlations. The discussion focuses on developments beyond the by now well established combination of density functional and dynamical mean field theory dubbed "LDA DMFT". It is organized around the description of dynamical screening effects in the solid. Indeed, screening in the solid gives rise to dynamical local Coulomb interactions U(w) (Aryasetiawan et al 2004 Phys. Rev. B 70 195104), and this frequ . . . . 






Nonlinear response in extended systems: a realtime approach 
Posted on 20161012
(Send to a Friend )


In this thesis we present a new formalism to study linear and nonlinear response in extended systems. Our approach is based on realtime solution of an effective Schr\"odinger equation. The coupling between electrons and external field is described by means of Modern Theory of Polarization. Correlation effects are derived from Green's function theory. We show that the inclusion of localfield effects and electronhole interaction is crucial to predict and reproduce second and third harmonic generation in low dimensional structures, where . . . . 






Quantum theory of spontaneous emission and coherent effects in semiconductor microstructures 
Posted on 20161012
(Send to a Friend )


A fully quantummechanical theory for the interaction of light and electron
}
hole excitations
in semiconductor quantumwell systems is developed. The resulting manybody hierarchy for
the correlation functions is truncated using a dynamical decoupling scheme leading to coupled
semiconductor luminescence and Bloch equations. For incoherent excitation conditions, the
theory is used to describe nonlinear excitonic emission properties of singlequantum wells,
optically coupled multiple quantumwell systems, and quantum wells in a microcavit . . . . 






Quasiparticle SelfConsistent GW Method for the Spectral Properties of Complex Materials 
Posted on 20161011
(Send to a Friend )


The GWapproximation to the formally exact manybody perturbation
theory has been applied successfully to materials for several decades. Since the
practical calculations are extremely cumbersome, the GW selfenergy is most
commonly evaluated using a firstorder perturbative approach: This is the
socalled G0W0 scheme. However, the
G0W0 approximation depends heavily on
the meanfield theory that is employed as a basis for the perturbation theory.
Recently, a procedure to reach a kind of selfconsistency within the
GW framework has been pr . . . . 










Quantum walks: a comprehensive review 
Posted on 20160723
(Send to a Friend )


Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers.
In this paper we review theoretical advances on the foundations of both discrete and continuoustime quantum walks, together with the role that randomness plays in qu . . . . 






Quantum random walks  an introductory overview 
Posted on 20160722
(Send to a Friend )


This article aims to provide an introductory survey on quantum random walks. Starting from a physical effect to illustrate the main ideas we will introduce quantum random walks, review some of their properties and outline their striking differences to classical walks. We will touch upon both physical effects and computer science applications, introducing some of the main concepts and language of present day quantum information science in this context. We will mention recent developments in this new area and outline some open questions.
. . . . 






A primer on quantum fluids 
Posted on 20160716
(Send to a Friend )


This book introduces the theoretical description and properties of quantum fluids. The focus is on gaseous atomic BoseEinstein condensates and, to a minor extent, superfluid helium, but the underlying concepts are relevant to other forms of quantum fluids such as polariton and photonic condensates. The book is pitched at the level of advanced undergraduates and early postgraduate students, aiming to provide the reader with the knowledge and skills to develop their own research project on quantum fluids. Indeed, the content for this book grew f . . . . 






An Introduction to Business Mathematics 
Posted on 20160713
(Send to a Friend )


These lecture notes provide a selfcontained introduction to the mathematical methods required in a Bachelor degree programme in Business, Economics, or Management. In particular, the topics covered comprise realvalued vector and matrix algebra, systems of linear algebraic equations, Leontief's stationary inputoutput matrix model, linear programming, elementary financial mathematics, as well as differential and integral calculus of realvalued functions of one real variable. A special focus is set on applications in quantitative economical mo . . . . 






Electronphonon interactions from first principles 
Posted on 20160617
(Send to a Friend )


This article reviews the theory of electronphonon interactions in solids from the point of view of abinitio calculations. While the electronphonon interaction has been studied for almost a century, predictive nonempirical calculations have become feasible only during the past two decades. Today it is possible to calculate from first principles many materials properties related to the electronphonon interaction, including the critical temperature of conventional superconductors, the carrier mobility in semiconductors, the temperature depend . . . . 






Response Theory of the ElectronPhonon Coupling 
Posted on 20160616
(Send to a Friend )


This article presents a systematic theoretical enquiry concerning the conceptual foundations and the nature of phononmediated electronelectron interactions. Starting from the fundamental manybody Hamiltonian, we propose a simple scheme to decouple the electrons and nuclei of a crystalline solid via effective interactions. These effective interactions, which we express in terms of linear response functions, are completely symmetric between electrons and nuclei. Correspondingly, we derive concrete formulae for both the effective electron inte . . . . 






Network Science 
Posted on 20160523
(Send to a Friend )


Networks are everywhere, from the Internet, to social networks, and the genetic networks that determine our biological existence. Illustrated throughout in full colour, this pioneering textbook, spanning a wide range of topics from physics to computer science, engineering, economics and the social sciences, introduces network science to an interdisciplinary audience. From the origins of the six degrees of separation to explaining why networks are robust to random failures, the author explores how viruses like Ebola and H1N1 spread, and why it i . . . . 






Pattern Recognition and Machine Learning 
Posted on 20160512
(Send to a Friend )


This new textbook reflects these recent developments while providing a compre
hensive introduction to the fields of pattern recognition and machine learning. It is
aimed at advanced undergraduates or first year PhD students, as well as researchers
and practitioners, and assumes no previous knowledge of pattern recognition or ma
chine learning concepts. Knowledge of multivariate calculus and basic linear algebra
is required, and some familiarity with probabilities would be helpful though not es
sential as the book includes a selfcontai . . . . 






Statistical Learning and Sequential Prediction 
Posted on 20160511
(Send to a Friend )


1
About
This course will focus on theoretical aspects of
Statistical Learning
and
Sequential
Prediction
. Until recently, these two subjects have been treated separately within
the learning community. The course will follow a unified approach to analyzing
learning in both scenarios. To make this happen, we shall bring together ideas
from probability and statistics, game theory, algorithms, and optimization. It is
this blend of ideas that makes the subject interesting for us, and we hope to convey
the excitement. We shall tr . . . . 






An Introduction to Statistical Learning: with Applications in R 
Posted on 20160509
(Send to a Friend )


One of the first books in this area—
The Elements of Statistical Learning
(ESL) (Hastie, Tibshirani, and Friedman)—was published in 2001, with a
second edition in 2009. ESL has become a popular text not only in statis
tics but also in related fields. One of the reasons for ESL’s popularity is
its relatively accessible style. But ESL is intended for individuals with ad
vanced training in the mathematical sciences.
An Introduction to Statistical
Learning
(ISL) arose from the perceived need for a broader and less tech
nical treatment . . . . 






The Elements of Statistical Learning 
Posted on 20160508
(Send to a Friend )


This book is our attempt to bring together many of the important new
ideas in learning, and explain them in a statistical framework. While some
mathematical details are needed, we emphasize the methods and their con
ceptual underpinnings rather than their theoretical properties. As a result,
we hope that this book will appeal not just to statisticians but also to
researchers and practitioners in a wide variety of fields. . . . . 






Dynamical screening in correlated electron systems  from lattice models to realistic materials 
Posted on 20160325
(Send to a Friend )


Recent progress in treating the dynamically screened nature of the Coulomb interaction in strongly correlated lattice models and materials is reviewed with a focus on computational schemes based on the dynamical mean field approximation. We discuss approximate and exact methods for the solution of impurity models with retarded interactions, and explain how these models appear as auxiliary problems in various extensions of the dynamical mean field formalism. The current state of the field is illustrated with results from recent applications of t . . . . 






Introduction to the Modeling and Analysis of Complex Systems 
Posted on 20160316
(Send to a Friend )


Introduction to the Modeling and Analysis of Complex Systems
introduces students to
mathematical/computational modeling and analysis developed in the emerging interdis
ciplinary field of
Complex Systems Science
. Complex systems are systems made of a
large number of microscopic components interacting with each other in nontrivial ways.
Many realworld systems can be understood as complex systems, where critically impor
tant information resides in the relationships between the parts and not necessarily within
the parts themselves.
T . . . . 






Copyright Oxford University Press 2006 v1. 0 Statistical Mechanics Entropy, Order Parameters, and Complexity 
Posted on 20160316
(Send to a Friend )


This text is careful to address the interests and background not only
of physicists, but of sophisticated students and researchers in mathe
matics, biology, engineering, comput
er science, and the social sciences.
It therefore does not presume an extensive background in physics, and
(except for Chapter
7
) explicitly does not assume that the reader knows
or cares about quantum mechanics. T
he text treats the intersection of
the interests of all of these groups
, while the exercises encompass the
union of interests. Statistical me . . . . 






Stochastic dynamics and relaxation in molecular systems 
Posted on 20160117
(Send to a Friend )


Contents: Langevin’s approach to Brownian dynamics; Diffusion processes and the FokkerPlanck equation; Diffusive motions in simple liquids; Protein dynamics; Elements of probability theory; Autoregressive model; Bibliography. . . . . 






Stochastic Differential Equations: Models and Numerics 
Posted on 20160117
(Send to a Friend )


The goal of this course is to give useful understanding for solving problems formulated by
stochastic differential equations models in science, engineering and mathematical finance.
Typically, these problems require numerical methods to obtain a solution and therefore
the course focuses on basic understanding of stochastic and partial differential equations
to construct reliable and efficient computational methods.
Stochastic and deterministic differential equations are fundamental for the modeling
in Science and Engineering. . . . . 






Control Principles of Complex Networks 
Posted on 20160102
(Send to a Friend )


A reflection of our ultimate understanding of a complex system is our ability to control its behavior. Typically, control has multiple prerequisites: It requires an accurate map of the network that governs the interactions between the system's components, a quantitative description of the dynamical laws that govern the temporal behavior of each component, and an ability to influence the state and temporal behavior of a selected subset of the components. With deep roots in nonlinear dynamics and control theory, notions of control and controllabi . . . . 






Introduzione all Intelligenza Artificiale 
Posted on 20160102
(Send to a Friend )


The paper presents an introduction to Artificial Intelligence (AI) in an accessible and informal but precise form. The paper focuses on the algorithmic aspects of the discipline, presenting the main techniques used in AI systems groped in symbolic and subsymbolic. The last part of the paper is devoted to the discussion ongoing among experts in the field and the public at large about on the advantages and disadvantages of AI and in particular on the possible dangers. The personal opinion of the author on this subject concludes the paper. . . . . 






Theory of Special Relativity 
Posted on 20151227
(Send to a Friend )


Special Relativity is taught to physics sophomores at Johns Hopkins University in a series of eight lectures. Lecture 1 covers the principle of relativity and the derivation of the Lorentz transform. Lecture 2 covers length contraction and time dilation. Lecture 3 covers Minkowski diagrams, simultaneous events and causally connected events, as well as velocity transforms. Lecture 4 covers energy and momentum of particles and introduces 4vectors. Lecture 5 covers energy and momentum of photons and collision problems. Lecture 6 covers Doppler ef . . . . 






Computational Sociolinguistics: A Survey 
Posted on 20151225
(Send to a Friend )


Language is a social phenomenon and inherent to its social nature is that it is constantly changing. Recently, a surge of interest can be observed within the computational linguistics (CL) community in the social dimension of language. In this article we present a survey of the emerging field of "Computational Sociolinguistics" that reflects this increased interest. We aim to provide a comprehensive overview of CL research on sociolinguistic themes, featuring topics such as the relation between language and social identity, langua . . . . 






Introduction to the variational and diffusion Monte Carlo methods 
Posted on 20151225
(Send to a Friend )


We provide a pedagogical introduction to the two main variants of realspace quantum Monte Carlo methods for electronicstructure calculations: variational Monte Carlo (VMC) and diffusion Monte Carlo (DMC). Assuming no prior knowledge on the subject, we review in depth the MetropolisHastings algorithm used in VMC for sampling the square of an approximate wave function, discussing details important for applications to electronic systems. We also review in detail the more sophisticated DMC algorithm within the fixednode approximation, introduce . . . . 


