Differential algebraic groups were introduced by P. Cassidy and E. Kolchin and are, roughly speaking, groups defined by algebraic differential equations in the same way as algebraic groups are groups defined by algebraic equations. The aim of the book is two-fold: 1) the provide an algebraic geometer's introduction to differential algebraic groups and 2) to provide a structure and classification theory for the finite dimensional ones. The main idea of the approach is to relate this topic to the study of: a) deformations of (not necessarily linear) algebraic groups and b) deformations of their automorphisms. The reader is assumed to possesssome standard knowledge of algebraic geometry but no familiarity with Kolchin's work is necessary. The book is both a research monograph and an introduction to a new topic and thus will be of interest to a wide audience ranging from researchers to graduate students.

This book explores what social psychology can contribute to our understanding of real-life problems and how it can inform rational interventions in any area of social life. By reviewing some of the most recent achievements in applying social psychology to pressing contemporary problems, Forgas, Crano, and Fiedler convey a fundamentally optimistic message about social psychology's achievements and prospects. The book is organized into four sections. Part I focuses on the basic issues and methods of applying social psychology to real-life problems, discussing evolutionary influences on human sociability, the role of psychological 'mindsets' in interpreting reality, and the use of attitude change techniques to promote adaptive behaviors. Part II explores the applications of social psychology to improve individual health and well-being, including managing aggression, eating disorders, and improving therapeutic interactions. Part III turns to the application of social psychology to improve interpersonal relations and communication, including attachment processes in social relationships, the role of parent-child interaction in preventing adolescent suicide, and analyzing social relations in legal settings and online social networks. Finally, Part IV addresses the question of how social psychology may improve our understanding of public affairs and political behavior. The book will be of interest to students and academics in social psychology, and professionals working in applied settings.

This book demonstrates the lively interaction between algebraic topology, very low dimensional topology and combinatorial group theory. Many of the ideas presented are still in their infancy, and it is hoped that the work here will spur others to new and exciting developments. Among the many techniques disussed are the use of obstruction groups to distinguish certain exact sequences and several graph theoretic techniques with applications to the theory of groups.

This research monograph provides a self-contained approach to the problem of determining the conditions under which a compact bordered Klein surface S and a finite group G exist, such that G acts as a group of automorphisms in S. The cases dealt with here take G cyclic, abelian, nilpotent or supersoluble and S hyperelliptic or with connected boundary. No advanced knowledge of group theory or hyperbolic geometry is required and three introductory chapters provide as much background as necessary on non-euclidean crystallographic groups. The graduate reader thus finds here an easy access to current research in this area as well as several new results obtained by means of the same unified approach.

This book grew out of lectures on spectral theory which the author gave at the Scuola. Normale Superiore di Pisa in 1985 and at the Universite Laval in 1987. Its aim is to provide a rather quick introduction to the new techniques of subhar- monic functions and analytic multifunctions in spectral theory. Of course there are many paths which enter the large forest of spectral theory: we chose to follow those of subharmonicity and several complex variables mainly because they have been discovered only recently and are not yet much frequented. In our book Pro- pri6t6$ $pectrale$ de$ algebre$ de Banach, Berlin, 1979, we made a first incursion, a rather technical one, into these newly discovered areas. Since that time the bushes and the thorns have been cut, so the walk is more agreeable and we can go even further. In order to understand the evolution of spectral theory from its very beginnings, it is advisable to have a look at the following books: Jean Dieudonne, Hutory of Functional AnaIY$u, Amsterdam, 1981; Antonie Frans Monna., Functional AnaIY$i$ in Hutorical Per$pective, Utrecht, 1973; and Frederic Riesz & Bela SzOkefalvi-Nagy, Le on$ d'anaIY$e fonctionnelle, Budapest, 1952. However the picture has changed since these three excellent books were written. Readers may convince themselves of this by comparing the classical textbooks of Frans Rellich, Perturbation Theory, New York, 1969, and Tosio Kato, Perturbation Theory for Linear Operator$, Berlin, 1966, with the present work.

This ground-breaking new volume reviews and extends theory and research on the psychology of justice in social contexts, exploring the dynamics of fairness judgments and their consequences. Perceptions of fairness, and the factors that cause and are caused by fairness perceptions, have long been an important part of social psychology. Featuring work from leading scholars on psychological processes involved in reactions to fairness, as well as the applications of justice research to government institutions, policing, medical care and the development of radical and extremist behavior, the book expertly brings together two traditionally distinct branches of social psychology: social cognition and interpersonal relations. Examining how people judge whether the treatment they experience from others is fair and how this effects their attitudes and behaviors, this essential collection draws on theory and research from multiple disciplines as it explores the dynamics of fairness judgments and their consequences. Integrating theory on interpersonal relations and social cognition, and featuring innovative biological research, this is the ideal companion for senior undergraduates and graduates, as well as researchers and scholars interested in the social psychology of justice.

- Qa faut avouer, dit Trouscaillon qui, dans cette simple ellipse, utilisait hyperboliquement Ie cercle vicieux de la parabole. - Bun, dit Ie Sanctimontronais, j'y vais. (R. Queneau, Zazie dans Ie metru, Chapitre X.) L'etude des groupes infinis a toujours ete en relation etroite avec des considerations geometriques: etude des deplacements de l'espace euclidien R3 (Jordan, 1868), programme d'Erlangen (Klein, 1872), travaux de Lie et Poincare. L'approche combinatoire des groupes, fondee sur la notion de presentation, remonte a Dyck (1882) mais doit son developpement en premier lieu a Dehn (des 1910) (voir ChM]). Les resultats decisifs de Dehn sur les groupes fondamentaux des sur faces sont marques par un ingredient geometrique crucial qui est la couTbuTe negati.ve. C'est ce me-me ingredient qui est ala base du tra vail fondamental de Gromov sur les groupes hyperboliques, conune on Ie voit esquisse dans Gr2, Gr4] et repris dans Gr5]. Nous sonuues cOllvaincus que l'importance de ce travail dans Ie developpement. de la theorie des groupes est comparable it ceux deja cites de Klein et Dehll."

This book deals with central simple Lie algebras over arbitrary fields of characteristic zero. It aims to give constructions of the algebras and their finite-dimensional modules in terms that are rational with respect to the given ground field. All isotropic algebras with non-reduced relative root systems are treated, along with classical anisotropic algebras. The latter are treated by what seems to be a novel device, namely by studying certain modules for isotropic classical algebras in which they are embedded. In this development, symmetric powers of central simple associative algebras, along with generalized even Clifford algebras of involutorial algebras, play central roles. Considerable attention is given to exceptional algebras. The pace is that of a rather expansive research monograph. The reader who has at hand a standard introductory text on Lie algebras, such as Jacobson or Humphreys, should be in a position to understand the results. More technical matters arise in some of the detailed arguments. The book is intended for researchers and students of algebraic Lie theory, as well as for other researchers who are seeking explicit realizations of algebras or modules. It will probably be more useful as a resource to be dipped into, than as a text to be worked straight through.

Determinantal rings and varieties have been a central topic of commutative algebra and algebraic geometry. Their study has attracted many prominent researchers and has motivated the creation of theories which may now be considered part of general commutative ring theory. The book gives a first coherent treatment of the structure of determinantal rings. The main approach is via the theory of algebras with straightening law. This approach suggest (and is simplified by) the simultaneous treatment of the Schubert subvarieties of Grassmannian. Other methods have not been neglected, however. Principal radical systems are discussed in detail, and one section is devoted to each of invariant and representation theory. While the book is primarily a research monograph, it serves also as a reference source and the reader requires only the basics of commutative algebra together with some supplementary material found in the appendix. The text may be useful for seminars following a course in commutative ring theory since a vast number of notions, results, and techniques can be illustrated significantly by applying them to determinantal rings.

The programme of the Conference at El Escorial included 4 main courses of 3-4 hours. Their content is reflected in the four survey papers in this volume (see above). Also included are the ten 45-minute lectures of a more specialized nature.

It is well known that there are close relations between classes of singularities and representation theory via the McKay correspondence and between representation theory and vector bundles on projective spaces via the Bernstein-Gelfand-Gelfand construction. These relations however cannot be considered to be either completely understood or fully exploited. These proceedings document recent developments in the area. The questions and methods of representation theory have applications to singularities and to vector bundles. Representation theory itself, which had primarily developed its methods for Artinian algebras, starts to investigate algebras of higher dimension partly because of these applications. Future research in representation theory may be spurred by the classification of singularities and the highly developed theory of moduli for vector bundles. The volume contains 3 survey articles on the 3 main topics mentioned, stressing their interrelationships, as well as original research papers.

The past several years have witnessed a striking number of important developments in Complex Analysis. One of the characteristics of these developments has been to bridge the gap existing between the theory of functions of one and of several complex variables. The Special Year in Complex Analysis at the University of Maryland, and these proceedings, were conceived as a forum where these new developments could be presented and where specialists in different areas of complex analysis could exchange ideas. These proceedings contain both surveys of different subjects covered during the year as well as many new results and insights. The manuscripts are accessible not only to specialists but to a broader audience. Among the subjects touched upon are Nevanlinna theory in one and several variables, interpolation problems in Cn, estimations and integral representations of the solutions of the Cauchy-Riemann equations, the complex Monge-AmpA]re equation, geometric problems in complex analysis in Cn, applications of complex analysis to harmonic analysis, partial differential equations.

All the papers in this volume are research papers presenting new results. Most of the results concern semi-simple Lie groups and non-Riemannian symmetric spaces: unitarisation, discrete series characters, multiplicities, orbital integrals. Some, however, also apply to related fields such as Dirac operators and characters in the general case.

This book provides an introduction to the theory of existentially closed groups, for both graduate students and established mathematicians. It is presented from a group theoretical, rather than a model theoretical, point of view. The recursive function theory that is needed is included in the text. Interest in existentially closed groups first developed in the 1950s. This book brings together a large number of results proved since then, as well as introducing new ideas, interpretations and proofs. The authors begin by defining existentially closed groups, and summarizing some of the techniques that are basic to infinite group theory (e.g. the formation of free products with amalgamation and HNN-extensions). From this basis the theory is developed and many of the more recently discovered results are proved and discussed. The aim is to assist group theorists to find their way into a corner of their subject which has its own characteristic flavour, but which is recognizably group theory.

From 1-4 April 1986 a Symposium on Algebraic Groups was held at the University of Utrecht, The Netherlands, in celebration of the 350th birthday of the University and the 60th of T.A. Springer. Recognized leaders in the field of algebraic groups and related areas gave lectures which covered wide and central areas of mathematics. Though the fourteen papers in this volume are mostly original research contributions, some survey articles are included. Centering on the Symposium subject, such diverse topics are covered as Discrete Subgroups of Lie Groups, Invariant Theory, D-modules, Lie Algebras, Special Functions, Group Actions on Varieties.

These notes are a record of a course given in Algiers from lOth to 21st May, 1965. Their contents are as follows. The first two chapters are a summary, without proofs, of the general properties of nilpotent, solvable, and semisimple Lie algebras. These are well-known results, for which the reader can refer to, for example, Chapter I of Bourbaki or my Harvard notes. The theory of complex semisimple algebras occupies Chapters III and IV. The proofs of the main theorems are essentially complete; however, I have also found it useful to mention some complementary results without proof. These are indicated by an asterisk, and the proofs can be found in Bourbaki, Groupes et Algebres de Lie, Paris, Hermann, 1960-1975, Chapters IV-VIII. A final chapter shows, without proof, how to pass from Lie algebras to Lie groups (complex-and also compact). It is just an introduction, aimed at guiding the reader towards the topology of Lie groups and the theory of algebraic groups. I am happy to thank MM. Pierre Gigord and Daniel Lehmann, who wrote up a first draft of these notes, and also Mlle. Franr: oise Pecha who was responsible for the typing of the manuscript.