The text of this book has its origins more than twenty- ve years ago. In the seminar of the Dutch Singularity Theory project in 1982 and 1983, the second-named author gave a series of lectures on Mixed Hodge Structures and Singularities, accompanied by a set of hand-written notes. The publication of these notes was prevented by a revolution in the subject due to Morihiko Saito: the introduction of the theory of Mixed Hodge Modules around 1985. Understanding this theory was at the same time of great importance and very hard, due to the fact that it uni es many di erent theories which are quite complicated themselves: algebraic D-modules and perverse sheaves. The present book intends to provide a comprehensive text about Mixed Hodge Theory with a view towards Mixed Hodge Modules. The approach to Hodge theory for singular spaces is due to Navarro and his collaborators, whose results provide stronger vanishing results than Deligne s original theory. Navarro and Guill en also lled a gap in the proof that the weight ltration on the nearby cohomology is the right one. In that sense the present book corrects and completes the second-named author s thesis."

This is the first comprehensive basic monograph on mixed Hodge structures. Starting with a summary of classic Hodge theory from a modern vantage point the book goes on to explain Deligne's mixed Hodge theory. Here proofs are given using cubical schemes rather than simplicial schemes. Next come Hain's and Morgan's results on mixed Hodge structures related to homotopy theory. Steenbrink's approach of the limit mixed Hodge structure is then explained using the language of nearby and vanishing cycle functors bridging the passage to Saito's theory of mixed Hodge modules which is the subject of the last chapter. Since here D-modules are essential, these are briefly introduced in a previous chapter. At various stages applications are given, ranging from the Hodge conjecture to singularities. The book ends with three large appendices, each one in itself a resourceful summary of tools and results not easily found in one place in the existing literature (homological algebra, algebraic and differential topology, stratified spaces and singularities). The book is intended for advanced graduate students, researchers in complex algebraic geometry as well as interested researchers in nearby fields (algebraic geometry, mathematical physics

The theory of motives was created by Grothendieck in the 1960s as he searched for a universal cohomology theory for algebraic varieties. The theory of pure motives is well established as far as the construction is concerned. Pure motives are expected to have a number of additional properties predicted by Grothendieck's standard conjectures, but these conjectures remain wide open. The theory for mixed motives is still incomplete. This book deals primarily with the theory of pure motives. The exposition begins with the fundamentals: Grothendieck's construction of the category of pure motives and examples. Next, the standard conjectures and the famous theorem of Jannsen on the category of the numerical motives are discussed. Following this, the important theory of finite dimensionality is covered. The concept of Chow-Künneth decomposition is introduced, with discussion of the known results and the related conjectures, in particular the conjectures of Bloch-Beilinson type. We finish with a chapter on relative motives and a chapter giving a short introduction to Voevodsky's theory of mixed motives.