Porte-Documents Vintage Parchemin

Sac à main en python des années 40. Le modèle est un classique à l'élégance intemporelle : il ne passe pas inaperçu et ne se démode jamais. Les conditions sont bonnes ; les petites imperfections du cuir sont dues au temps.

Porte-monnaie de Cesare Piccini vraisemblablement des années 1960, en velours marron avec une bande de couleur jaune et noire. Le manche est également en velours. La fermeture du sac est particulière: un simple anneau en acier est tiré à l'extérieur et ouvre la fermeture. À l'intérieur du miroir est incorporé dans la poche. Les conditions sont excellentes, seule la peau est légèrement marquée à l'intérieur du sac.

Simon Kirwan Donaldson, S. K. Donaldson, P. B. Kronheimer
Clarendon Press

This book provides the first lucid and accessible account to the modern study of the geometry of four-manifolds. It has become required reading for postgraduates and research workers whose research touches on this topic. Pre-requisites are a firm grounding in differential topology, andgeometry as may be gained from the first year of a graduate course. The subject matter of this book is the most significant breakthrough in mathematics of the last fifty years, and Professor Donaldson won a Fields medal for his work in the area. The authors start from the standpoint that thefundamental group and intersection form of a four-manifold provides information about its homology and characteristic classes, but little of its differential topology. It turns out that the classification up to diffeomorphism of four-manifolds is very different from the classification of unimodularforms and that the study of this question leads naturally to the new Donaldson invariants of four-manifolds. A central theme of this book is that the appropriate geometrical tools for investigating these questions come from mathematical physics: the Yang-Mills theory and anti-self dual connectionsover four-manifolds. One of the many consquences of this theory is that 'exotic' smooth manifolds exist which are homeomorphic but not diffeomorphic to (4, and that large classes of forms cannot be realized as intersection forms whereas distinct manifolds may share the same form. These result havehad far-reaching consequences in algebraic geometry, topology, and mathematical physics, and will continue to be a mainspring of mathematical research for years to come.