On the Slope and Geography of Fibred Surfaces and Threefolds. 

Barja Yáñez, Miguel Ángel (Date of defense: 1998-12-21)

In this tesis we study numerical propieties of surfaces and threefolds, mainly fibred over curves, the so called "slope" of the fibration. We prove partially a conjecture of Fujita on the semiampleness of the direct image ...