The purpose of this CIME summer school was to present current areas of research arising both in the theoretical and applied setting that involve fully nonlinear partial different equations. The equations presented in the school stem from the fields of Conformal Mapping Theory, Differential Geometry, Optics, and Geometric Theory of Several Complex Variables. The school consisted of four courses: Extremal problems for quasiconformal mappings in space by Luca Capogna, Fully nonlinear equations in geometry by Pengfei Guan, Monge-Ampere type equations and geometric optics by Cristian E. Gutierrez, and On the Levi Monge Ampere equation by Annamaria Montanari.

A conference, to celebrate the 65th birthday of Professor James Serrin, was held at the University of Ferrara from 26 to 30 October 1992, on the occasion of the sixth centenary of the foundation of the university. The dual purpose of this conference was to honor James Serrin and to bring together mathematicians in four main areas of Professor Serrin's research in terests: partial differential equations, variational methods, fluid mechanics, and thermodynamics. These fields, with their significant historical connotation, still remain the object of active research and development, and possess a remarkable degree of interrelation in their pure and applied aspects. Thus the organizing committee, consisting of G. Buttazzo, G.P. Galdi, E. Lanconelli, and P. Pucci, had the opportunity to invite a number of well-known mathematicians and friends of James Serrin to make this meeting a success. An honorary committee was also formed, including Professor A. Rossi, Rector of the University of Ferrara, Professor C. Bighi, President of the Accadernia Scienze di Ferrara, Professor G. Del Piero, Decano of the Faculty of Engineering of the University of Ferrara, and Professor L. Zanghirati, Director of the Department of Mathematics of the University of Ferrara. The conference was further supported by G.N.A.F.A., G.N.F.M., and the Mathematics Committee of the Consiglio Nazionale delle Ricerche, together with the University of Ferrara and the Cassa di Risparrnio of Ferrara, to all of whom the organizing committee expresses their most sincere thanks."

This book provides an extensive treatment of Potential Theory for sub-Laplacians on stratified Lie groups. It also provides a largely self-contained presentation of stratified Lie groups, and of their Lie algebra of left-invariant vector fields. The presentation is accessible to graduate students and requires no specialized knowledge in algebra or differential geometry.

This volume contains the notes of the lectures delivered at the CIME course GeometricAnalysis andPDEsduringtheweekofJune11-162007inCetraro (Cosenza). The school consisted in six courses held by M. Gursky (PDEs in Conformal Geometry), E. Lanconelli (Heat kernels in sub-Riemannian s- tings), A. Malchiodi(Concentration of solutions for some singularly perturbed Neumann problems), G. Tarantello (On some elliptic problems in the study of selfdual Chern-Simons vortices), X. J. Wang (Thek-Hessian Equation)and P. Yang (Minimal Surfaces in CR Geometry). Geometric PDEs are a ?eld of research which is currently very active, as it makes it possible to treat classical problems in geometry and has had a dramatic impact on the comprehension of three- and four-dimensional ma- folds in the last several years. On one hand the geometric structure of these PDEs might cause general di?culties due to the presence of some invariance (translations, dilations, choice of gauge, etc. ), which results in a lack of c- pactness of the functional embeddings for the spaces of functions associated with the problems. On the other hand, a geometric intuition or result might contribute enormously to the search for natural quantities to keep track of, andtoproveregularityoraprioriestimatesonsolutions. Thistwo-foldaspect of the study makes it both challenging and complex, and requires the use of severalre?nedtechniquestoovercomethemajordi?cultiesencountered

This book provides an extensive treatment of Potential Theory for sub-Laplacians on stratified Lie groups. It also provides a largely self-contained presentation of stratified Lie groups, and of their Lie algebra of left-invariant vector fields. The presentation is accessible to graduate students and requires no specialized knowledge in algebra or differential geometry.